SpringBoot Controller中各个注解的使用(三)

ゝ一世哀愁。 2024-02-18 20:30 34阅读 0赞

**Controller的使用**

<table style="border-spacing:0px;background-color:rgb(253,253,253);color:rgb(51,51,51);font-family:'Helvetica Neue', Helvetica, Arial, sans-serif;font-size:14px;"> 
 <tbody> 
 <tr> 
 <td style="padding:0px;">@Controller</td> 
 <td style="padding:0px;">处理http请求（整体页面刷新提交的处理注解）</td> 
 </tr> 
 <tr> 
 <td style="padding:0px;">@RestController</td> 
 <td style="padding:0px;">Spring4之后新加的注解，原来返回json需要@ResponseBody配合@Controller（ajax提交，一般返回json格式）</td> 
 </tr> 
 <tr> 
 <td style="padding:0px;">@RequestMapping</td> 
 <td style="padding:0px;">配置url映射</td> 
 </tr> 
 </tbody> 
</table>

**Controller的url路径参数**

@PathVariable 获取url中的数据

@RequestParam 获取请求参数中的值

**一.@Controller整体页面交互**

请求后台，必须返回一个视图，以前我们一般用Jsp，但是SpringBoot不推荐我们实用jsp，主要是强调前后台分离；

官方推荐的是这几种模版视图引擎，

![20180526112954903][]

推荐Freemarker和Velocity；

首先，添加Freemarker支持，打开pom.xml文件，alt+/

![2018052611310828][]

弹出对话框

![20180526113122215][]

选择Freemarker

![20180526113129787][]

此时，在pom.xml文件

![20180526113233869][]

配置application.properties文件

![20180526113313448][]

FreemarkerController控制器

package com.hlx.controller;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.servlet.ModelAndView;
    
    @Controller
    public class FreemarkerController {
    
    	@RequestMapping("/show")
    	public ModelAndView show() {
    		ModelAndView view = new ModelAndView("he");
    		view.addObject("msg", "Freemarker Template Language 模板引擎!");
    		return view;
    
    	}
    }

工程如下：

![20180526113402512][]

he.ftl

![20180526113620909][]

页面访问

![20180526113349963][]

二.@RestController ajax页面交互

package com.hlx.controller;
    
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    @RequestMapping("/ajax")
    public class AjaxController {
    	
    	@RequestMapping("/json")
    	public String disable(){
    		String json="{'msg1':'测试ajax!','msg2':'获得json的数据!'}";
    		return json;
    	}
    
    }

index.html

<html>
 <head>
 <meta charset="UTF-8">
 <title>Insert title here</title>
 </head>
 
 <script type="text/javascript" src="jquery-3.2.1.js"></script>
 
 <script type="text/javascript">
 $(function(){
 	//单击事件
 	$("#but").click(function(){	
 		//异步post提交
 		$.post("ajax/json",{},function(data){
 			alert(data);
 		});
 			
 	});
 	
 });
 
 
 </script>
 <body>
 <input type="button" id="but" value="单击我！">
 <a href="/hello3/path/208">使用pathVariable中的数据</a>
 <hr/>
 
 <a href="/hello3/path/find?uname=bear&upass=aaa">使用requestParameter参数的数据</a>
 
 <a href="/hello3/path/find?uname=mike">使用requestParameter参数的数据</a>
 </body>
 </html>

![20180526113958462][]

浏览页面

![20180526114013816][]

这里的json比较简单，所以我直接返回； 实际项目Json格式复杂，要借助于一些json框架，比如Json-lib，gson等等；

**三.介绍url地址上的参数使用**

import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.servlet.ModelAndView;
    
    @Controller
    @RequestMapping("/path")
    public class PathController {
    
    	@RequestMapping("/{id}")
    	public ModelAndView show(@PathVariable("id") Integer id){
    		//试图对象
    		ModelAndView view=new ModelAndView("blog");
    		//保存数据
    		view.addObject("id", id);
    		return view;
    	}
    	
    	
    	@RequestMapping("/find")
    	public ModelAndView param(@RequestParam(value="uname",required=false) String uname, @RequestParam(value="upass",required=false) String pwd){
    		//试图对象
    		ModelAndView view=new ModelAndView("param");
    		//保存数据
    		view.addObject("name", uname);
    		view.addObject("pwd",pwd);
    		return view;
    	}
    }

**(1)@PathVariable 获取url中的数据**

![20180526114333355][]

![20180526114343598][]

**(2)@RequestParam 获取请求参数中的值**

注意：（required=false）这个参数可以传也可以不传哦！

**param.ftl**

**![20180526114459995][]**

**![20180526114416235][]**

**![20180526114426755][]**

、

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