springMVC之异常处理



来自：http://blog.youkuaiyun.com/zdp072/article/details/38693027

1. 自定义一个异常类: UserException.java

[java] view plain copy print ?

1. public class UserException extends RuntimeException {  
2.   
3.     private static final long serialVersionUID = 1L;  
4.   
5.     public UserException() {  
6.         super();  
7.     }  
8.   
9.     public UserException(String message, Throwable cause) {  
10.         super(message, cause);  
11.     }  
12.   
13.     public UserException(String message) {  
14.         super(message);  
15.     }  
16.   
17.     public UserException(Throwable cause) {  
18.         super(cause);  
19.     }  
20.   
21. }  

public class UserException extends RuntimeException {

	private static final long serialVersionUID = 1L;

	public UserException() {
		super();
	}

	public UserException(String message, Throwable cause) {
		super(message, cause);
	}

	public UserException(String message) {
		super(message);
	}

	public UserException(Throwable cause) {
		super(cause);
	}

}

2. 使用用户登录的例子: UserController.java

   假定用户名不存在或用户密码错误系统会抛出异常, 并跳到error.jsp页面

[java] view plain copy print ?

1. @Controller  
2. @RequestMapping("/user")  
3. public class UserController {  
4.     // 使用map模拟数据库   
5.     private Map<String, User> userMap = new HashMap<String, User>();  
6.   
7.     public UserController() {  
8.         userMap.put("zhangsan", new User("zhangsan", "123"));  
9.         userMap.put("lishimin", new User("lishimin", "456"));  
10.     }  
11.       
12.     // 用户登录之异常处理  
13.     // 访问方法: http://localhost/springmvc_user/login.jsp  
14.     @RequestMapping(value="/login", method=RequestMethod.POST)  
15.     public String login(String username, String password, HttpSession session) {  
16.         if(!userMap.containsKey(username)) {  
17.             throw new UserException("用户名不存在");  
18.         }  
19.         User user = userMap.get(username);   
20.         if(!user.getPassword().equals(password)) {  
21.             throw new UserException("用户密码不正确");  
22.         }  
23.         session.setAttribute("loginUser", user);  
24.         return "redirect:/user/users";  
25.     }  
26.       
27.     /** 
28.      * 局部异常处理(只能处理这个控制器中的异常) 
29.      */  
30.     @ExceptionHandler(value={UserException.class})  
31.     public String handlerException(UserException e,HttpServletRequest request) {  
32.         request.setAttribute("exception",e);   
33.         return "exception/error";  
34.     }  
35.       
36. }  

@Controller
@RequestMapping("/user")
public class UserController {
	// 使用map模拟数据库 
	private Map<String, User> userMap = new HashMap<String, User>();

	public UserController() {
		userMap.put("zhangsan", new User("zhangsan", "123"));
		userMap.put("lishimin", new User("lishimin", "456"));
	}
	
	// 用户登录之异常处理
	// 访问方法: http://localhost/springmvc_user/login.jsp
	@RequestMapping(value="/login", method=RequestMethod.POST)
	public String login(String username, String password, HttpSession session) {
		if(!userMap.containsKey(username)) {
			throw new UserException("用户名不存在");
		}
		User user = userMap.get(username); 
		if(!user.getPassword().equals(password)) {
			throw new UserException("用户密码不正确");
		}
		session.setAttribute("loginUser", user);
		return "redirect:/user/users";
	}
	
	/**
	 * 局部异常处理(只能处理这个控制器中的异常)
	 */
	@ExceptionHandler(value={UserException.class})
	public String handlerException(UserException e,HttpServletRequest request) {
		request.setAttribute("exception",e); 
		return "exception/error";
	}
	
}

3. 配置全局异常处理: user-servlet.xml

[html] view plain copy print ?

1. <!-- 全局异常处理 -->  
2. <bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">  
3.     <property name="exceptionMappings">  
4.         <props>  
5.             <prop key="com.zdp.exception.UserException">exception/error</prop>  
6.         </props>  
7.     </property>  
8. </bean>  

<!-- 全局异常处理 -->
<bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
	<property name="exceptionMappings">
		<props>
			<prop key="com.zdp.exception.UserException">exception/error</prop>
		</props>
	</property>
</bean>

4. 错误信息页面: error.jsp

[html] view plain copy print ?

1. <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>  
2. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">  
3. <html>  
4. <head>  
5. <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">  
6. <title>错误页面</title>  
7. </head>  
8. <body>  
9. 发现错误: ${exception.message}  
10. </body>  
11. </html>  

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>错误页面</title>
</head>
<body>
发现错误: ${exception.message}
</body>
</html>