springMVC controller中方法的返回值类型

不念不忘少年蓝@ 2022-06-14 04:17 275阅读 0赞

## 具体介绍 ##

详细介绍每一个返回类型的各个特点；

## ModelAndView ##

<table style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
 <tbody style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
  <tr style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
   <td style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:3em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; color:rgb(175,175,175)!important"> <code style="word-break:break-all; padding:0px 0.3em 0px 0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; text-align:right!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:2.7em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; display:block!important">3</code></td> 
   <td style="padding:0px 0px 0px 0.5em!important; margin:0px!important; border-width:0px 0px 0px 3px!important; border-left-style:solid!important; border-left-color:rgb(108,226,108)!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> <code style="word-break:break-all; color:rgb(64,170,83); padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">ModelAndView modelAndView =&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:rgb(0,102,153)!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-weight:bold!important; font-size:10pt!important; min-height:inherit!important">new</code>&nbsp;<code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">ModelAndView(</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:blue!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">"/user/index"</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">);</code></td> 
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 </tbody> 
</table>

<table style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
 <tbody style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
  <tr style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
   <td style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:3em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; color:rgb(175,175,175)!important"> <code style="word-break:break-all; padding:0px 0.3em 0px 0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; text-align:right!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:2.7em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; display:block!important">4</code></td> 
   <td style="padding:0px 0px 0px 0.5em!important; margin:0px!important; border-width:0px 0px 0px 3px!important; border-left-style:solid!important; border-left-color:rgb(108,226,108)!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> <code style="word-break:break-all; color:rgb(64,170,83); padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">modelAndView.addObject(</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:blue!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">"xxx"</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">,&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:blue!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">"xxx"</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">);</code></td> 
  </tr> 
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通过ModelAndView构造方法可以指定返回的页面名称，也可以通过setViewName()方法跳转到指定的页面 ,  
使用addObject()设置需要返回的值，addObject()有几个不同参数的方法，可以默认和指定返回对象的名字。  
调用addObject()方法将值设置到一个名为ModelMap的类属性，ModelMap是LinkedHashMap的子类，  
具体请看类。

<table style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
 <tbody style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
  <tr style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
   <td style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:3em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; color:rgb(175,175,175)!important"> <code style="word-break:break-all; padding:0px 0.3em 0px 0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; text-align:right!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:2.7em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; display:block!important">4</code></td> 
   <td style="padding:0px 0px 0px 0.5em!important; margin:0px!important; border-width:0px 0px 0px 3px!important; border-left-style:solid!important; border-left-color:rgb(108,226,108)!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> <code style="word-break:break-all; color:rgb(64,170,83); padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">modelAndView.addObject(</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:blue!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">"xxx"</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">,&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:blue!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">"xxx"</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">);</code></td> 
  </tr> 
 </tbody> 
</table>

对于ModelAndView类的属性和方法

[![39754432_1.jpg][]][39754432_1.jpg]

## Model ##

一个模型对象，主要包含[spring][]封装好的model和modelMap,以及[Java][spring].util.Map，当没有视图返回的时候视图名称将由requestToViewNameTranslator决定；**Model 是一个接口， 其实现类为ExtendedModelMap，继承了ModelMap类。**

## ModelMap ##

待续

## Map ##

<table style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
 <tbody style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
  <tr style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
   <td style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:3em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; color:rgb(175,175,175)!important"> <code style="word-break:break-all; padding:0px 0.3em 0px 0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; text-align:right!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:2.7em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; display:block!important">3</code></td> 
   <td style="padding:0px 0px 0px 0.5em!important; margin:0px!important; border-width:0px 0px 0px 3px!important; border-left-style:solid!important; border-left-color:rgb(108,226,108)!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> <code style="word-break:break-all; color:rgb(64,170,83); padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">Map&lt;String, String&gt; map =&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:rgb(0,102,153)!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-weight:bold!important; font-size:10pt!important; min-height:inherit!important">new</code>&nbsp;<code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">HashMap&lt;String, String&gt;();</code></td> 
  </tr> 
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</table>

PS：响应的view应该也是该请求的view。等同于void返回。

Java代码

1.  @RequestMapping("/demo2/show")  
2.      publicMap<String, String> getMap() \{  
3.          Map<String, String> map = newHashMap<String, String>();  
4.          map.put("key1", "value-1");  
5.          map.put("key2", "value-2");  
6.          returnmap;  
7.      \}

在jsp页面中可直通过$\{key1\}获得到值, map.put()相当于request.setAttribute方法。  
写例子时发现，key值包括 - . 时会有问题.

## View ##

这个时候如果在渲染页面的过程中模型的话，就会给处理器方法定义一个模型参数，然后在方法体里面往模型中添加值。可以返回pdf excel等，暂时没详细了解。

## String ##

对于String的返回类型，笔者是配合Model来使用的；

或者通过配合@ResponseBody来将内容或者对象作为HTTP响应正文返回（适合做即时校验）；

<table style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
 <tbody style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
  <tr style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
   <td style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:3em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; color:rgb(175,175,175)!important"> <code style="word-break:break-all; padding:0px 0.3em 0px 0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; text-align:right!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:2.7em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; display:block!important">3</code></td> 
   <td style="padding:0px 0px 0px 0.5em!important; margin:0px!important; border-width:0px 0px 0px 3px!important; border-left-style:solid!important; border-left-color:rgb(108,226,108)!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> <code style="word-break:break-all; color:rgb(64,170,83); padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">&nbsp;&nbsp;&nbsp;&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">String valid(</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:rgb(128,128,128)!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">@RequestParam</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">(value =&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:blue!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">"userId"</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">, required =&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:rgb(0,102,153)!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-weight:bold!important; font-size:10pt!important; min-height:inherit!important">false</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">) Integer userId,</code></td> 
  </tr> 
 </tbody> 
</table>

<table style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
 <tbody style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
  <tr style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
   <td style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:3em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; color:rgb(175,175,175)!important"> <code style="word-break:break-all; padding:0px 0.3em 0px 0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; text-align:right!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:2.7em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; display:block!important">4</code></td> 
   <td style="padding:0px 0px 0px 0.5em!important; margin:0px!important; border-width:0px 0px 0px 3px!important; border-left-style:solid!important; border-left-color:rgb(108,226,108)!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> <code style="word-break:break-all; color:rgb(64,170,83); padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:rgb(128,128,128)!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">@RequestParam</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">(value =&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:blue!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">"logName"</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">) String strLogName) { </code></td> 
  </tr> 
 </tbody> 
</table>

ps:返回字符串表示一个视图名称，这个时候如果需要在渲染视图的过程中需要模型的话，就可以给处理器添加一个模型参数，然后在方法体往模型添加值就可以了，

String 指定返回的视图页面名称，结合设置的返回地址路径加上页面名称后缀即可访问到。  
注意：如果方法声明了注解@ResponseBody ，则会直接将返回值输出到页面。  
例如：

Java代码

1.  @RequestMapping(value = "/something", method = RequestMethod.GET)  
2.  @ResponseBody  
3.  publicString helloWorld()  \{  
4.  return"Hello World";  
5.  \}

上面的结果会将文本"Hello World "直接写到http响应流。

Java代码

1.  @RequestMapping("/welcome")  
2.  publicString welcomeHandler() \{  
3.    return"center";  
4.  \}

返回字符串代表的意义：  
1）：字符串代表逻辑视图名

真实的访问路径=“前缀”+逻辑视图名+“后缀”

注意：如果返回的String代表逻辑视图名的话，那么Model的返回方式如下：

public String testController(Model model)\{  
model.addAttribute(attrName,attrValue);//相当于ModelAndView的addObject方法  
return "逻辑视图名";  
   \}

2）：代表redirect重定向

redirect的特点和servlet一样，使用redirect进行重定向那么地址栏中的URL会发生变化，同时不会携带上一次的request

案例：

public String testController(Model model)\{  
return "redirect:path";//path代表重定向的地址  
\}

3）：代表forward转发

通过forward进行转发，地址栏中的URL不会发生改变，同时会将上一次的request携带到写一次请求中去

案例：  
public String testController(Model model)\{  
return "forward:path";//path代表转发的地址  
\}

详细例子参考：http://blog.csdn.net/u011001084/article/details/52847174

## Void ##

当返回类型为Void的时候，则响应的视图页面为对应着的访问地址

<table style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
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   <td style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:3em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; color:rgb(175,175,175)!important"> <code style="word-break:break-all; padding:0px 0.3em 0px 0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; text-align:right!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:2.7em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; display:block!important">03</code></td> 
   <td style="padding:0px 0px 0px 0.5em!important; margin:0px!important; border-width:0px 0px 0px 3px!important; border-left-style:solid!important; border-left-color:rgb(108,226,108)!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> <code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:rgb(0,102,153)!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-weight:bold!important; font-size:10pt!important; min-height:inherit!important">public</code>&nbsp;<code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:rgb(0,102,153)!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-weight:bold!important; font-size:10pt!important; min-height:inherit!important">class</code>&nbsp;<code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">TypeController&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:rgb(0,102,153)!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-weight:bold!important; font-size:10pt!important; min-height:inherit!important">extends</code>&nbsp;<code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">AbstractBaseController{ </code></td> 
  </tr> 
 </tbody> 
</table>

<table style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
 <tbody style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
  <tr style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> 
   <td style="padding:0px!important; margin:0px!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:3em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; color:rgb(175,175,175)!important"> <code style="word-break:break-all; padding:0px 0.3em 0px 0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; text-align:right!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:2.7em!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important; display:block!important">08</code></td> 
   <td style="padding:0px 0px 0px 0.5em!important; margin:0px!important; border-width:0px 0px 0px 3px!important; border-left-style:solid!important; border-left-color:rgb(108,226,108)!important; outline:0px!important; float:none!important; vertical-align:top!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important"> <code style="word-break:break-all; color:rgb(64,170,83); padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">modelAndView.addObject(</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:blue!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">"xxx"</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">,&nbsp;</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; color:blue!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">"xxx"</code><code style="word-break:break-all; padding:0px!important; margin:0px!important; font-family:Consolas,&quot;Bitstream Vera Sans Mono&quot;,&quot;Courier New&quot;,Courier,monospace!important; border:0px!important; outline:0px!important; float:none!important; vertical-align:baseline!important; position:static!important; left:auto!important; top:auto!important; right:auto!important; bottom:auto!important; height:auto!important; width:auto!important; line-height:1.1em!important; font-size:10pt!important; min-height:inherit!important">);</code></td> 
  </tr> 
 </tbody> 
</table>

返回的结果页面还是：/type

PS:这个时候我们一般是将返回结果写在了HttpServletResponse 中了，如果没写的话，[spring][]就会利用RequestToViewNameTranslator 来返回一个对应的视图名称。如果这个时候需要模型的话，处理方法和返回字符串的情况是相同的。

小结：  
1.使用 String 作为请求处理方法的返回值类型是比较通用的方法，这样返回的逻辑视图名不会和请求 URL 绑定，具有很大的灵活性，而模型数据又可以通过 ModelMap 控制。  
2.使用void,map,Model 时，返回对应的逻辑视图名称真实url为：prefix前缀+视图名称 +suffix后缀组成。  
3.使用String,ModelAndView返回视图名称可以不受请求的url绑定，ModelAndView可以设置返回的视图名称。

Model model,HttpServletRequest request, ModelMap map声明变量  
  
request.getSession().setAttribute("test", "haiwei2Session");  
request.setAttribute("test", "haiwei1request");   
map.addAttribute("test", "haiweiModelMap");  
model.addAttribute("test", "haiweiModel");  
  
**我通过$\{test\}这个方式取值，优先取Model和ModelMap的，Model和ModelMap是同一个东西，谁最后赋值的就取谁的，然后是request，最后是从session中获取**

[39754432_1.jpg]: http://image70.360doc.com/DownloadImg/2014/03/0919/39754432_1.jpg
[spring]: http://lib.csdn.net/base/javaee