JAVA高级面试进阶训练营视频教程

admin

系统：WIN8.1

数据库：Oracle 11GR2

开发工具：MyEclipse 8.6

框架：Spring3.2.9、SpringMVC3.2.9、MyBatis3.2.8

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使用SpringMVC开发的时候，页面如果有日期格式的数据，后台接受也是java.util.Date，则报告400错误 。下面是解决方案的演示示例：

 

这个是实体类，里面createDate就是java.util.Date类型

 1 import java.util.Date;
 2 
 3 public class User {
 4 
 5     private int userId;
 6     private String userName;
 7     private Date createDate;
 8     
 9     public User() {}
10 
11     public User(int userId, String userName, Date createDate) {
12         super();
13         this.userId = userId;
14         this.userName = userName;
15         this.createDate = createDate;
16     }
17 
18     public User(String userName, Date createDate) {
19         super();
20         this.userName = userName;
21         this.createDate = createDate;
22     }
23 
24     public int getUserId() {
25         return userId;
26     }
27 
28     public void setUserId(int userId) {
29         this.userId = userId;
30     }
31 
32     public String getUserName() {
33         return userName;
34     }
35 
36     public void setUserName(String userName) {
37         this.userName = userName;
38     }
39 
40     public Date getCreateDate() {
41         return createDate;
42     }
43 
44     public void setCreateDate(Date createDate) {
45         this.createDate = createDate;
46     }
47 
48     @Override
49     public String toString() {
50         return "User [createDate=" + createDate + ", userId=" + userId
51                 + ", userName=" + userName + "]";
52     }
53 }

页面代码

1 　　<form action="regUser" method="post">
2         userName:<input type="text" name="userName"/><br>
3         createDate:<input type="text" name="createDate"/><br>
4         double类型:<input type="text" name="dd"/><br>
5         <input type="submit" value="注册">
6     </form>

 因为对于原生基本类型的form表单绑定，会出错。需要指定具体的类型编辑器。用法如下：首先在BaseController中增加方法initBinder，并使用注解@InitBinder标注，那么spring mvc在绑定表单之前，都会先注册这些编辑器。剩下的控制器都继承该类。CustomDateEditor spring自己已经提供了。代码如下：

 1 import java.text.SimpleDateFormat;
 2 import java.util.Date;
 3 
 4 import org.springframework.beans.propertyeditors.CustomDateEditor;
 5 import org.springframework.stereotype.Controller;
 6 import org.springframework.web.bind.WebDataBinder;
 7 import org.springframework.web.bind.annotation.InitBinder;
 8 
 9 import sun.beans.editors.DoubleEditor;
10 import sun.beans.editors.FloatEditor;
11 import sun.beans.editors.IntEditor;
12 import sun.beans.editors.LongEditor;
13 
14 @Controller
15 public class BaseController {
16 
17     @InitBinder    
18     public void initBinder(WebDataBinder binder) {    
19 
20         binder.registerCustomEditor(Date.class, new CustomDateEditor(new SimpleDateFormat("yyyy-MM-dd"), true)); 
21         binder.registerCustomEditor(int.class, new IntEditor());
22         binder.registerCustomEditor(long.class, new LongEditor());  
23         binder.registerCustomEditor(double.class, new DoubleEditor());  
24         binder.registerCustomEditor(float.class, new FloatEditor());  
25     }
26     
27     
28 }

上面的代码不仅仅有日期格式的编辑器，还有基础类型的编辑器，这样就解决了SpringMVC中controller方法接受参数的时候，基础类型报错的问题了。

下面是测试用代码，继承BaseController之后就可以直接运行了。接受的参数有实体类和基础类型。

 1 import org.springframework.stereotype.Controller;
 2 import org.springframework.web.bind.annotation.RequestMapping;
 3 
 4 import com.kickstarter.entity.User;
 5 
 6 @Controller("userController")
 7 public class UserController extends BaseController{
 8 
 9     @RequestMapping(value="regUser")
10     public String dateTest(User user , double dd){
11         
12         System.out.println( user.toString() );
13         System.out.println( dd );
14         return "index"; 
15     }
16 }

以上，问题解决。然后我们切换第二种方式，删除 BaseController 这个类，直接在User实体类中的 createDate字段上加上注解 ， 注意第10行代码：

 1 import java.util.Date;
 2 
 3 import org.springframework.format.annotation.DateTimeFormat;
 4 
 5 public class User {
 6 
 7     private int userId;
 8     private String userName;
 9     
10     @DateTimeFormat(pattern="yyyy-MM-dd")
11     private Date createDate;
12     
13     public User() {}
14 
15     public User(int userId, String userName, Date createDate) {
16         super();
17         this.userId = userId;
18         this.userName = userName;
19         this.createDate = createDate;
20     }
21 
22     public User(String userName, Date createDate) {
23         super();
24         this.userName = userName;
25         this.createDate = createDate;
26     }
27 
28     public int getUserId() {
29         return userId;
30     }
31 
32     public void setUserId(int userId) {
33         this.userId = userId;
34     }
35 
36     public String getUserName() {
37         return userName;
38     }
39 
40     public void setUserName(String userName) {
41         this.userName = userName;
42     }
43 
44     public Date getCreateDate() {
45         return createDate;
46     }
47 
48     public void setCreateDate(Date createDate) {
49         this.createDate = createDate;
50     }
51 
52     @Override
53     public String toString() {
54         return "User [createDate=" + createDate + ", userId=" + userId
55                 + ", userName=" + userName + "]";
56     }
57 }

这样也可以解决日期格式报400问题。而且不管页面是否有数据都可以正常使用。