ControllerAdvice注解的使用-蒲公英云

为了方便对异常的统一管理，spring mvc提供了ControllerAdvice注解对异常进行统一的处理，拿到这些异常信息后，可以做一些处理，比如提供一个统一的web界面查看异常信息，或者普通到异常信息后，发送短信、邮件形式通知到相关人员，可以帮助开发人员快速发现并定位问题，减少以往通过查看线上日志文件排查问繁琐锁耗时的所耗费的时间。下面我跟大家介绍具体步骤。

配置

spring 版本：

<org.springframework-version>4.1.9.RELEASE</org.springframework-version>

spring-servlet.xml，注意必须开启注解，即xml要有

<?xml version="1.0" encoding="UTF-8"?>  
<beans:beans xmlns="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:beans="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">  
    <!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->  
    <!-- Enables the Spring MVC @Controller programming model -->  
    <annotation-driven />  
    <!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->  
    <resources mapping="/resources/**" location="/resources/" />  
    <!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->  
    <beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">  
        <beans:property name="prefix" value="/WEB-INF/views/" />  
        <beans:property name="suffix" value=".jsp" />  
    </beans:bean>  
    <context:component-scan base-package="org.as.asjee" use-default-filters="false">  
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>  
    </context:component-scan>  
</beans:beans>

异常统一处理类

package org.as.asjee.core.exception;
import java.sql.SQLException;
import javax.servlet.http.HttpServletRequest;
import org.as.asjee.core.log.AsJEELogger;
import org.as.asjee.core.log.AsJEELoggerFactory;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
/** * 捕获异常统一处理 * @description TODO * @author chen.gs * @create date 2016年4月28日 * @modified by * @modify date * @version v1.0 */
@ControllerAdvice
public class GlobalExceptionHandler {
    private final static AsJEELogger LOG = AsJEELoggerFactory.getLogger(GlobalExceptionHandler.class);
    private final static String EXPTION_MSG_KEY = "message";
    @ExceptionHandler(BusinessException.class)
    @ResponseBody
    public void handleBizExp(HttpServletRequest request, Exception ex){
        LOG.info("Business exception handler " + ex.getMessage() );
        request.getSession(true).setAttribute(EXPTION_MSG_KEY, ex.getMessage());
    }
    @ExceptionHandler(SQLException.class)
    public ModelAndView handSql(Exception ex){
        LOG.info("SQL Exception " + ex.getMessage());
        ModelAndView mv = new ModelAndView();
        mv.addObject("message", ex.getMessage());
        mv.setViewName("sql_error");
        return mv;
    }
}

自定义异常类BussinessException.java

package org.as.asjee.core.exception;
/** * 业务异常 * @description TODO * @author chen.gs * @create date 2016年4月28日 * @modified by * @modify date * @version v1.0 */
public class BusinessException extends Exception{ 
    private static final long serialVersionUID = 1L;
    //业务类型
    private String bizType;
    //业务代码
    private int bizCode;
    //错误信息
    private String message;
    public BusinessException(String bizType, int bizCode, String message){
        super(message);
        this.bizType = bizType;
        this.bizCode = bizCode;
        this.message = message;
    }
    public BusinessException(String message){
        super(message);
        this.bizType = "";
        this.bizCode = -1;
        this.message = message;
    }
    public BusinessException(String bizType, String message){
        super(message);
        this.bizType = bizType;
        this.bizCode = -1;
        this.message = message;
    }
    public BusinessException(int bizCode, String message){
        super(message);
        this.bizType = "";
        this.bizCode = bizCode;
        this.message = message;
    }
    public String getBizType() {
        return bizType;
    }
    public void setBizType(String bizType) {
        this.bizType = bizType;
    }
    public int getBizCode() {
        return bizCode;
    }
    public void setBizCode(int bizCode) {
        this.bizCode = bizCode;
    }
    public String getMessage() {
        return message;
    }
    public void setMessage(String message) {
        this.message = message;
    }
}

controller

package org.as.asjee.core.security.web;
import java.sql.SQLException;
import javax.annotation.Resource;
import org.as.asjee.core.exception.BusinessException;
import org.as.asjee.core.security.model.User;
import org.as.asjee.core.security.service.UserService;
import org.as.asjee.core.service.ServiceFacade;
import org.as.asjee.core.web.AbstractController;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
@RequestMapping("/security/user")
public class UserController extends AbstractController<User>{ 
    @Resource
    private UserService userService;
    @Resource
    private ServiceFacade serviceFacade;
    @RequestMapping("login")
    public String login() { 
        return "login";
    }
    @RequestMapping("login2")
    public String login2() throws Exception {
        throw new SQLException("出错鸟。。。。。。。。。");
    }   
    @RequestMapping("login3")
    public String login3() throws Exception { 
        throw new BusinessException("业务执行异常");
    }
    //此方法抛出的异常不是由GlobalExceptionHandler处理
    //而是在catch块处理
    @RequestMapping("login4")
    public String login4() { 
        try {
            throw new BusinessException("业务执行异常");
        } catch (BusinessException e) {
            e.printStackTrace();
        }
        return "login";
    }
}

简要说明

在Controller中抛出的异常，当没有被catch处理时，GlobalExceptionHandler中定义的处理方法可以起作用，在方法写明注解@ExceptionHandler，并注明其异常类即可。此种方法不仅可以作用于Controller，同样的在DAO层、service层也可，都可以由GlobalExceptionHandler进行处理。此种写法减少代码的入侵，值得推荐。
异常的统一处理只是注解ControllerAdvice用处之一，有兴趣了解更多的，请到spring官网查阅。