SpringMVC -- 梗概--源码--贰--异常管理
附：实体类
Class ： User
package com.c61.entity; import java.text.SimpleDateFormat; import java.util.Date; import org.springframework.format.annotation.DateTimeFormat; import com.alibaba.fastjson.annotation.JSONField; public class User { private Integer id; private String name; //@DateTimeFormat(pattern="yyyy-MM-dd HH:mm:ss") @DateTimeFormat(pattern="yyyy-MM-dd")//定制在接收请求参数时的日期格式 @JSONField(format="yyyy-MM-dd")//作用在java序列化成json时 private Date birth; private String dateStr; public String getDateStr() { return dateStr; } public void setDateStr(String dateStr) { this.dateStr = dateStr; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Date getBirth() { return birth; } public void setBirth(Date birth) { this.birth = birth; SimpleDateFormat format=new SimpleDateFormat("yyyy-MM-dd"); this.dateStr=format.format(birth); } @Override public String toString() { return "User [id=" + id + ", name=" + name + ", birth=" + birth + "]"; } public User(){} public User(Integer id, String name, Date birth) { super(); this.id = id; this.name = name; this.birth = birth; } }
Class ： LoginErrorException
package com.c61.exception; public class LoginErrorException extends RuntimeException{ public LoginErrorException(){} public LoginErrorException(String msg){ super(msg); } }
Class ： AException
package com.c61.exception; public class AException extends RuntimeException{ public AException(){} public AException(String msg){ super(msg); } }
Class ： UserServiceImpl
package com.c61.service; import com.c61.exception.AException; import com.c61.exception.LoginErrorException; public class UserServiceImpl implements UserService{ public void login(String username, String password) { //登录业务 if(!"c61".equals(username)){ //日志 throw new LoginErrorException("用户名无效"); }else if(!"123".equals(password)){ //日志 throw new LoginErrorException("密码无效"); }else if(username.length()<10){ throw new AException("test"); } //正常的登录逻辑控制 //...... } }
1.配置web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <display-name></display-name> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> <!-- 前端控制器 /=默认的url-pattern /a/b/c /a /a/d/c /a/d /a / *注意：此控制器默认加载/WEB-INF下的xxx-servlet.xml文件 ：其中xxx等于【DispatcherServlet的配置名】 --> <servlet> <servlet-name>mvc61</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:mvc62.xml</param-value> </init-param> <!-- 随项目启动而启动 --> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>mvc61</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <!-- 专治Post请求参数乱码 --> <filter> <filter-name>encoding61</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <!-- 将请求的编码方式设置为utf-8 --> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>encoding61</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>
2.配置SpringMVC.xml
<?xml version="1.0" encoding="utf-8"?> <!-- xmlns:xml name space 是每一个schema唯一标识 --> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd"> <!-- 扫描所有控制器中的注解 --> <context:component-scan base-package="com.c61.controller"></context:component-scan> <!-- MVC中基于注解开发，导入注解驱动 <mvc:annotation-driven/> --> <mvc:annotation-driven> <mvc:message-converters> <bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter"> <property name="supportedMediaTypes"> <list> <!-- 支持的格式：application/json --> <value>application/json</value> </list> </property> </bean> </mvc:message-converters> </mvc:annotation-driven> <!-- 视图解析器：解析视图 控制器方法的返回值，会被视图解析器捕获。"abc" 根据捕获的内容，解析出一个视图地址:/abc.jsp --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/"></property> <property name="suffix" value=".jsp"></property> </bean> <!-- 静态资源：html,js,css,jpg 访问404 解决 --> <mvc:default-servlet-handler/> <!-- 声明异常处理器 --> <bean class="com.c61.ex.resolver.MyExceptionResolver"></bean> <!-- 拦截器配置 --> <!-- /a/b inter1 inter2 拦截顺序：先配置先拦截 具体顺序：pre1==pre2==contorller==post2==post1==after2==after1 --> <mvc:interceptors> <mvc:interceptor> <!-- 定义要拦截的路径 /inter/* 匹配 /inter/a /inter/b inter/cssdafasfsafs 不能匹配/inter/a/b /inter/** 匹配 /inter/a /inter/xxsjaflsajf /inter/a/b/c/e/d/xxxcvx *注意：exclude-mapping不能单独使用。要配合mapping使用 ：在mapping匹配的范围中排除一些个。 --> <mvc:mapping path="/inter/**"/> <mvc:mapping path="/a/b"/> <mvc:mapping path="/c/**"/> <mvc:exclude-mapping path="/inter/test/*"/> <mvc:exclude-mapping path="/c/b/**"/> <!-- 声明拦截器 --> <bean class="com.c61.interceptor.MyInterceptor"/> </mvc:interceptor> <mvc:interceptor> <!-- 定义要拦截的路径 --> <mvc:mapping path="/inter/test"/> <!-- 声明拦截器 --> <bean class="com.c61.interceptor.MyInterceptor2"/> </mvc:interceptor> </mvc:interceptors> <!-- 声明文件上传解析器 注意：此解析器，id必须为：multipartResolver --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- 最大允许的上传大小 byte --> <property name="MaxUploadSize" value="2097152"></property> </bean> <!-- 注册，验证码生成器 --> <bean id="captcha" class="com.google.code.kaptcha.servlet.KaptchaExtend"> <constructor-arg> <props> <!-- 是否有边框 边框颜色 边框粗细 --> <prop key="kaptcha.border">no</prop> <prop key="kaptcha.border.color">105,179,90</prop> <prop key="kaptcha.border.thickness">20</prop> <prop key="kaptcha.textproducer.font.color">black</prop> <prop key="kaptcha.image.width">200</prop> <prop key="kaptcha.image.height">50</prop> <prop key="kaptcha.textproducer.font.size">40</prop> <prop key="kaptcha.session.key">code61</prop> <prop key="kaptcha.textproducer.char.length">4</prop> <prop key="kaptcha.textproducer.font.names">Arial,Courier</prop> <!-- <prop key="kaptcha.background.clear.from">black</prop> <prop key="kaptcha.background.clear.to">255,0,0</prop> --> </props> </constructor-arg> </bean> </beans>
3.配置控制器
Class ： ExceptionController
package com.c61.controller; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import com.c61.service.UserService; import com.c61.service.UserServiceImpl; @Controller @RequestMapping("/ex") public class ExceptionController { /*private UserService us=new UserServiceImpl(); public String login(String username,String password){ try{ us.login(username, password); }catch(LoginErrorException e){ return "redirect:/login.jsp"; }catch(AException e){ return "redirect:/xxx.jsp"; }catch(Exception e){ } return "forward:/index.jsp"; }*/ private UserService us=new UserServiceImpl(); @RequestMapping("/login") public String login(String username,String password){ us.login(username,password); return "forward:/index.jsp"; } }
4.定制异常管理器
Class ： MyExceptionResolver
package com.c61.ex.resolver; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException; import org.springframework.web.multipart.MaxUploadSizeExceededException; import org.springframework.web.servlet.HandlerExceptionResolver; import org.springframework.web.servlet.ModelAndView; import com.c61.exception.AException; import com.c61.exception.LoginErrorException; /* * 异常处理器：所有Controller中抛出的所有异常，都由此处理器接收并处理。 */ public class MyExceptionResolver implements HandlerExceptionResolver{ /** * 主体逻辑：自动捕获Controller中的异常,每当Controller中抛出异常时，就会执行。 * param:ex=当前抛出的异常 * req=请求对象 * res=响应对象 * handler=抛出异常的控制器方法 */ public ModelAndView resolveException(HttpServletRequest req, HttpServletResponse res, Object handler, Exception ex) { System.out.println(ex.getClass()); //System.out.println(req.getClass()+" "+res.getClass()+" "+handler.getClass()); System.out.println("异常处理~~~~"+ex.getMessage()); ModelAndView mav=new ModelAndView(); //识别异常 if(ex instanceof LoginErrorException){ mav.setViewName("redirect:/error1.jsp"); }else if(ex instanceof AException){ mav.setViewName("redirect:/error2.jsp"); }else if(ex instanceof MaxUploadSizeExceededException){ mav.setViewName("redirect:/error4.jsp"); }else{ mav.setViewName("redirect:/error3.jsp"); } return mav; } }
5.声明异常管理器
XML ： SpringMVC.xml
<!-- 声明异常处理器 --> <bean class="com.c61.ex.resolver.MyExceptionResolver"></bean>
6.配置视图
View ： errer1.jsp
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> This is my error1 JSP page. <br> </body> </html>
View ： errer2.jsp
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> This is my error2 JSP page. <br> </body> </html>
View ： errer3.jsp
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> This is my error3 JSP page. <br> </body> </html>
View ： errer4.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> 请上传小于2M的文件 </body> </html>
异常管理
定制异常管理器
public class MyExceptionResolver implements HandlerExceptionResolver{
/**
* 主体逻辑：自动捕获Controller中的异常,每当Controller中抛出异常时，就会执行。
* param:ex=当前抛出的异常
* req=请求对象
* res=响应对象
* handler=抛出异常的控制器方法
* 返回值：ModelAndView=用来返回错误页面
*/
public ModelAndView resolveException(HttpServletRequest req,
HttpServletResponse res, Object handler, Exception ex) {
ModelAndView mav=new ModelAndView();
//识别异常
if(ex instanceof LoginErrorException){
mav.setViewName("redirect:/error1.jsp");
}else if(...){}
...
return mav;
}
}
声明
<bean class="com.c61.ex.resolver.MyExceptionResolver"></bean>
异常管理器作用
作用：统一抽取了所有控制器中的异常处理逻辑
抽取前：
public String login(String username,String password){
try{
us.login(username, password);
}catch(LoginErrorException e){
return "redirect:/login.jsp";
}catch(AException e){
return "redirect:/xxx.jsp";
}catch(Exception e){
}
return "forward:/index.jsp";
}
抽取后：
public String login(String username,String password){
us.login(username,password);
return "forward:/index.jsp";
}
啦啦啦
