SpringMVC的异常处理

异常处理的思路

1.Controller调用service，service调用dao，异常都是向上抛出的，最终由DispatcherServlet找异常处理器进行异常的处理。

1、编写自定义异常类（做提示信息）

package net.togogo.exception;

/**
 * 自定义的异常类
 */
public class SysException extends Exception{
    private String message;

    public SysException(String message) {
        this.message = message;
    }

    @Override
    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

2、编写异常处理器

package net.togogo.exception;

import org.springframework.web.servlet.HandlerExceptionResolver;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 异常处理器
 */
public class SysExceptionResolver implements HandlerExceptionResolver {

    /**
     * 处理异常逻辑
     * @param httpServletRequest
     * @param httpServletResponse
     * @param o
     * @param e
     * @return
     */
    @Override
    public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {
        //获取到异常处理对象
        SysException sysException = null;
        if(e instanceof SysException){
            sysException = (SysException)e;
        }else{
            sysException = new SysException("系统正在维护。。");
        }
        //创建ModelAndView对象
        ModelAndView mv = new ModelAndView();
        mv.addObject("errorMsg",sysException.getMessage());
        mv.setViewName("error");
        return mv;
    }
}

3、配置异常处理器

<!--配置异常处理器-->
    <bean id="sysExceptionResolver" class="net.togogo.exception.SysExceptionResolver"/>