springMVC类型转换，@initBinder使用

川长思鸟来 2022-08-06 03:15 245阅读 0赞

[http://jwlsky.iteye.com/blog/1890676][http_jwlsky.iteye.com_blog_1890676]

**1：代码实例**

Java代码 [ ![复制代码][icon_copy.gif]][_icon_copy.gif]  ![收藏代码][icon_star.png]![spinner.gif][]

1.  @InitBinder 
2.  public void initBinder(WebDataBinder binder) \{ 
3.   
4.   
5.      SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd"); 
6.      dateFormat.setLenient(false); 
7.      binder.registerCustomEditor(Date.class, new CustomDateEditor(dateFormat, true)); 
8.   
9.   
10.     binder.registerCustomEditor(SystemInfo.class, new PropertyEditorSupport() \{ 
11.  
12.         @Override 
13.         public void setAsText(String text) throws IllegalArgumentException \{ 
14.             if (!StringUtils.hasText(text)) \{ 
15.                 return; 
16.             \} 
17.             \{ 
18.                 Long systemInfoId = Long.valueOf(text); 
19.                 SystemInfo systemInfo = systemInfoService.findById(systemInfoId); 
20.                 setValue(systemInfo); 
21.             \} 
22.         \} 
23.     \}); 
24.  
25.     binder.registerCustomEditor(Category.class, new PropertyEditorSupport() \{ 
26.  
27.         @Override 
28.         public void setAsText(String text) throws IllegalArgumentException \{ 
29.             if (!StringUtils.hasText(text)) \{ 
30.                 return; 
31.             \} else \{ 
32.                 Long categoryId = Long.valueOf(text); 
33.                 Category category = categoryService.findById(categoryId); 
34.                 setValue(category); 
35.             \} 
36.         \} 
37.     \}); 
38. \}

@InitBinder
        public void initBinder(WebDataBinder binder) {
    
    
            SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
            dateFormat.setLenient(false);
            binder.registerCustomEditor(Date.class, new CustomDateEditor(dateFormat, true));
    
    
            binder.registerCustomEditor(SystemInfo.class, new PropertyEditorSupport() {
    
                @Override
                public void setAsText(String text) throws IllegalArgumentException {
                    if (!StringUtils.hasText(text)) {
                        return;
                    }
                    {
                        Long systemInfoId = Long.valueOf(text);
                        SystemInfo systemInfo = systemInfoService.findById(systemInfoId);
                        setValue(systemInfo);
                    }
                }
            });
    
            binder.registerCustomEditor(Category.class, new PropertyEditorSupport() {
    
                @Override
                public void setAsText(String text) throws IllegalArgumentException {
                    if (!StringUtils.hasText(text)) {
                        return;
                    } else {
                        Long categoryId = Long.valueOf(text);
                        Category category = categoryService.findById(categoryId);
                        setValue(category);
                    }
                }
            });
        }

Html代码 [ ![复制代码][icon_copy.gif 1]][_icon_copy.gif 1]  ![收藏代码][icon_star.png 1]![spinner.gif 1][]

1.              <form:form modelAttribute="categoryEditForm" id="categoryForm" method="post" action="saveOrUpdate.do"> 
2.                
3.              <form:hidden path="category.objectId" /> 
4.              <input type="hidden" name="category.parent" value="$\{categoryEditForm.category.parent.objectId\}"/> 
5.              <input type="hidden" name="category.systemInfo" value="$\{categoryEditForm.category.systemInfo.objectId \}"/> 
6.                
7.              <div class="area"> 
8.                  <div class="areaTitle"> 
9.                      <div class="inner"> 
10.                         <label>Category Information Form</label> 
11.                         <div class="clear"></div> 
12.                     </div> 
13.                 </div> 
14.             </div> 
15.               
16.             <div class="areaBody"> 
17.     <table class="formTable"> 
18.                     <tbody> 
19.                         <tr> 
20.                 <td colspan="4"> 
21.                     <span class="button"><span><a href="javascript:sumbit();" class="btnSave">Submit</a></span></span> 
22.                 </td> 
23.             </tr>   
24.             <tr> 
25.                 <td colspan="4">&nbsp;</td> 
26.             </tr> 
27.             <tr> 
28.                 <td align="right">Parent Category Name:</td> 
29.                 <td colspan="3"><form:input path="category.parent.name.fullName" readonly="true" id="parentCategory" cssClass="input readOnly" /></td>                                          
30.             </tr> 
31.             <tr> 
32.                 <td align="right">Current Category Name:</td> 
33.                 <td><form:input path="category.name.fullName" id="categoryName" cssClass="input"/></td> 
34.                 <td align="right">description:</td> 
35.                 <td><form:input path="category.description" id="description" cssClass="input"/></td> 
36.             </tr> 
37.                     </tbody> 
38.                         </table> 
39.             </div> 
40.               
41. </form:form>

**2、实例2**

# spring mvc的表单类型转换(custom property editor) #

*9*人收藏此文章, 我要收藏发表于7个月前(2012-10-28 14:14) , 已有 **329**次阅读 ，共 **[1][]**个评论

spring mvc的表单类型转换太强大了，目前用到了两个简单的，

一个是将表单中的file自动映射成byte\[\],这样文件上传（如果使用blob）就无需写任何代码了。

另一个是将表单中的yyyy-MM-dd格式映射成java.util.Date，

假设User.java中有如下这两种特殊的属性：

注册这两种属性编辑器只需在Controller中定义如下这样一个`initBinder`方法:

ByteArrayMultipartFileEditor和CustomDateEditor都是spring直接提供的。可以参考这两个类的源码,

高级的自定义的还没用过，等用到的时候再补充到这里(2012-11-04补充）

今天终于用到了自定义的Editor，我现在有一个User对象，它有一个Set<Role> roles集合。

Role有id和name属性，

UserController如下

我的user\_new.jsp如下：

<table style="border-width:0px!important; margin:0px; padding:0px!important; width:auto!important; height:auto!important; text-align:left!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important; border-collapse:collapse!important"> 
 <tbody> 
  <tr style="border-width:0px!important; margin:0px; padding:0px!important; width:auto!important; height:auto!important; text-align:left!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important"> 
   <td style="border-width:0px!important; margin:0px; padding:0px!important; width:3em!important; height:auto!important; text-align:left!important; color:rgb(175,175,175)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:top!important; float:none!important"> <code style="margin:0px; padding:0px 0.3em 0px 0px!important; border:0px solid rgb(221,221,221); width:2.7em!important; height:auto!important; text-align:right!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important; display:block!important">2</code></td> 
   <td style="margin:0px; padding:0px 0px 0px 0.5em!important; width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,0,0)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:top!important; border-left-color:rgb(108,226,108); border-top-width:0px!important; border-right-width:0px!important; border-bottom-width:0px!important; border-left-width:3px; border-left-style:solid; float:none!important"> <code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">&nbsp;&nbsp;&nbsp; </code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,0,0)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">&lt;</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,102,153)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:bold!important; vertical-align:baseline!important; float:none!important">label</code> <code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(128,128,128)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">class</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,0,0)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">=</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:blue!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">"control-label"</code> <code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(128,128,128)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">for</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,0,0)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">=</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:blue!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">"roles"</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,0,0)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">&gt;角色:&lt;/</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,102,153)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:bold!important; vertical-align:baseline!important; float:none!important">label</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,0,0)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">&gt;</code></td> 
  </tr> 
 </tbody> 
</table>

<table style="border-width:0px!important; margin:0px; padding:0px!important; width:auto!important; height:auto!important; text-align:left!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important; border-collapse:collapse!important"> 
 <tbody> 
  <tr style="border-width:0px!important; margin:0px; padding:0px!important; width:auto!important; height:auto!important; text-align:left!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important"> 
   <td style="border-width:0px!important; margin:0px; padding:0px!important; width:3em!important; height:auto!important; text-align:left!important; color:rgb(175,175,175)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:top!important; float:none!important"> <code style="margin:0px; padding:0px 0.3em 0px 0px!important; border:0px solid rgb(221,221,221); width:2.7em!important; height:auto!important; text-align:right!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important; display:block!important">4</code></td> 
   <td style="margin:0px; padding:0px 0px 0px 0.5em!important; width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,0,0)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:top!important; border-left-color:rgb(108,226,108); border-top-width:0px!important; border-right-width:0px!important; border-bottom-width:0px!important; border-left-width:3px; border-left-style:solid; float:none!important"> <code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,0,0)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">&lt;</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,102,153)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:bold!important; vertical-align:baseline!important; float:none!important">sf:checkboxes</code> <code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(128,128,128)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">path</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,0,0)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">=</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:blue!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">"roles"</code> <code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(128,128,128)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">items</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,0,0)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">=</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:blue!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">"${roleList }"</code> <code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(128,128,128)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">itemValue</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,0,0)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">=</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:blue!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">"id"</code> <code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(128,128,128)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">itemLabel</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,0,0)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">=</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:blue!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">"name"</code><code style="margin:0px; padding:0px!important; border:0px solid rgb(221,221,221); width:auto!important; height:auto!important; text-align:left!important; color:rgb(0,0,0)!important; line-height:1.1em!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:10pt!important; font-style:normal!important; font-weight:normal!important; vertical-align:baseline!important; float:none!important">/&gt;</code></td> 
  </tr> 
 </tbody> 
</table>

用户在页面上check一个或多个角色，提交form，这时我们期望user对象中的roles集合能自动绑定用户选择的值，但是提交到服务器上的数据其实是一组roleId，我们需要在自定义的PropertyEditor中将其转成Role对象.

可以像这样定义RoleEditor.java

并在UserController中的initBinder方法中注册该编辑器

这时在UserController的create方法中取得的User对象就是已经绑定了roles的了

值得注意的是，你必须要覆写Role的equals和hashCode方法，不然当你进入修改页面时，user的role属性不会自动的check上。

RoleEditor可以简化成  
public class RoleEditor extends PropertyEditorSupport \{  
  @Override  
  public void setAsText(String text) throws IllegalArgumentException \{  
    if (text != null) \{  
      Role role = new Role();  
      role.setId(Long.valueOf(text));  
      setValue(role);  
    \} else \{  
      setValue(null);  
    \}  
  \}  
\}  
保存时只用了id值，没有必要去数据库再查找一次

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