Spring全局异常处理的三种方式

 

全局的异常处理

1，配置异常解析器

 

SimpleMappingExceptionResolver 或者实现HandlerExceptionResolver接口自动以异常解析器

 

 

2，直接用全局的异常处理注解（@ControllerAdvice）

 

@ExceptionHandler（单用的话只能拦截当前类，配合@ControllerAdvice可以拦截所有的controller）

 

 

在异常处理的通知逻辑方法中可以控制遇到异常之后是跳转页面，还是返回json

 

 

跳转页面

protected ModelAndView handleViewError(String url, String errorStack, String errorMessage, String viewName) {    

     ModelAndView mav = new ModelAndView();    

     mav.addObject("exception", errorStack);    

     mav.addObject("url", url);   

     mav.addObject("message", errorMessage); 

     mav.addObject("timestamp", new Date());    

     mav.setViewName(viewName);  

     return mav;  

    }  

 

 

 返回json

   protected ModelAndView handleAjaxError(HttpServletResponse rsp, String errorMessage, HttpStatus status) throws IOException {    

      rsp.setCharacterEncoding("UTF-8");    

      rsp.setStatus(status.value());   

      PrintWriter writer = rsp.getWriter();

      writer.write(errorMessage);    

      writer.flush();    

      return null;  

   }  

 

 

 

在J2EE项目的开发中，不管是对底层的数据库操作过程，还是业务层的处理过程，还是控制层的处理过程，都不可避免会遇到各种可预知的、不可预知的异常需要处理。每个过程都单独处理异常，系统的代码耦合度高，工作量大且不好统一，维护的工作量也很大。 那么，能不能将所有类型的异常处理从各处理过程解耦出来，这样既保证了相关处理过程的功能较单一，也实现了异常信息的统一处理和维护？答案是肯定的。下面将介绍使用Spring MVC统一处理异常的解决和实现过程

• 使用Spring MVC提供的SimpleMappingExceptionResolver
• 实现Spring的异常处理接口HandlerExceptionResolver 自定义自己的异常处理器
• 使用@ExceptionHandler注解实现异常处理

(一) SimpleMappingExceptionResolver 

使用这种方式具有集成简单、有良好的扩展性、对已有代码没有入侵性等优点，但该方法仅能获取到异常信息，若在出现异常时，对需要获取除异常以外的数据的情况不适用。

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@Configuration @EnableWebMvc @ComponentScan(basePackages = {"com.balbala.mvc.web"}) public class WebMVCConfig extends WebMvcConfigurerAdapter{  @Bean   public SimpleMappingExceptionResolver simpleMappingExceptionResolver()   {     SimpleMappingExceptionResolver b = new SimpleMappingExceptionResolver();     Properties mappings = new Properties();     mappings.put("org.springframework.web.servlet.PageNotFound", "page-404");     mappings.put("org.springframework.dao.DataAccessException", "data-access");     mappings.put("org.springframework.transaction.TransactionException", "transaction-Failure");     b.setExceptionMappings(mappings);     return b;   } }

(二) HandlerExceptionResolver

相比第一种来说,HandlerExceptionResolver能准确显示定义的异常处理页面,达到了统一异常处理的目标

1.定义一个类实现HandlerExceptionResolver接口,这次贴一个自己以前的代码

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package com.athena.common.handler; import com.athena.common.constants.ResponseCode; import com.athena.common.exception.AthenaException; import com.athena.common.http.RspMsg; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.web.servlet.HandlerExceptionResolver; import org.springframework.web.servlet.ModelAndView; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.PrintWriter; /**  * Created by sam on 15/4/14.  */ public class GlobalHandlerExceptionResolver implements HandlerExceptionResolver {   private static final Logger LOG = LoggerFactory.getLogger(GlobalHandlerExceptionResolver.class);           /**     * 在这里处理所有得异常信息     */    @Override    public ModelAndView resolveException(HttpServletRequest req,                     HttpServletResponse resp, Object o, Exception ex) {      ex.printStackTrace();       if (ex instanceof AthenaException) {        //AthenaException为一个自定义异常       ex.printStackTrace();           printWrite(ex.toString(), resp);         return new ModelAndView();     }      //RspMsg为一个自定义处理异常信息的类     //ResponseCode为一个自定义错误码的接口     RspMsg unknownException = null;       if (ex instanceof NullPointerException) {          unknownException = new RspMsg(ResponseCode.CODE_UNKNOWN, "业务判空异常", null);     } else {           unknownException = new RspMsg(ResponseCode.CODE_UNKNOWN, ex.getMessage(), null);    }         printWrite(unknownException.toString(), resp);        return new ModelAndView();    }     /**     * 将错误信息添加到response中     *     * @param msg     * @param response     * @throws IOException     */    public static void printWrite(String msg, HttpServletResponse response) {        try {             PrintWriter pw = response.getWriter();           pw.write(msg);           pw.flush();           pw.close();        } catch (Exception e) {            e.printStackTrace();        }    } }

2.加入spring的配置中,这里只贴出了相关部分

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import com.athena.common.handler.GlobalHandlerExceptionResolver; import org.springframework.context.annotation.Bean; import com.athena.common.handler.GlobalHandlerExceptionResolver; import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter; /**  * Created by sam on 15/4/14.  */ public class WebSpringMvcConfig extends WebMvcConfigurerAdapter {     @Bean   public GlobalHandlerExceptionResolver globalHandlerExceptionResolver() {    return new GlobalHandlerExceptionResolver();   } }

(三)@ExceptionHandler

这是笔者现在项目的使用方式,这里也仅贴出了相关部分

1.首先定义一个父类,实现一些基础的方法

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package com.balabala.poet.base.spring; import com.google.common.base.Throwables; import com.raiyee.poet.base.exception.MessageException; import com.raiyee.poet.base.utils.Ajax; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.core.annotation.AnnotationUtils; import org.springframework.http.HttpStatus; import org.springframework.web.bind.annotation.ResponseStatus; import org.springframework.web.servlet.ModelAndView; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.PrintWriter; import java.util.Date;   public class BaseGlobalExceptionHandler {     protected static final Logger logger = null;     protected static final String DEFAULT_ERROR_MESSAGE = "系统忙，请稍后再试";      protected ModelAndView handleError(HttpServletRequest req, HttpServletResponse rsp, Exception e, String viewName, HttpStatus status) throws Exception {       if (AnnotationUtils.findAnnotation(e.getClass(), ResponseStatus.class) != null)         throw e;        String errorMsg = e instanceof MessageException ? e.getMessage() : DEFAULT_ERROR_MESSAGE;         String errorStack = Throwables.getStackTraceAsString(e);         getLogger().error("Request: {} raised {}", req.getRequestURI(), errorStack);         if (Ajax.isAjax(req)) {           return handleAjaxError(rsp, errorMsg, status);       }         return handleViewError(req.getRequestURL().toString(), errorStack, errorMsg, viewName);    }       protected ModelAndView handleViewError(String url, String errorStack, String errorMessage, String viewName) {         ModelAndView mav = new ModelAndView();         mav.addObject("exception", errorStack);         mav.addObject("url", url);        mav.addObject("message", errorMessage);      mav.addObject("timestamp", new Date());         mav.setViewName(viewName);       return mav;      }       protected ModelAndView handleAjaxError(HttpServletResponse rsp, String errorMessage, HttpStatus status) throws IOException {          rsp.setCharacterEncoding("UTF-8");          rsp.setStatus(status.value());         PrintWriter writer = rsp.getWriter();       writer.write(errorMessage);          writer.flush();          return null;     }       public Logger getLogger() {          return LoggerFactory.getLogger(BaseGlobalExceptionHandler.class);    } }

2.针对你需要捕捉的异常实现相对应的处理方式

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package com.balabala.poet.base.spring; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.http.HttpStatus; import org.springframework.web.bind.annotation.ControllerAdvice; import org.springframework.web.bind.annotation.ExceptionHandler; import org.springframework.web.bind.annotation.ResponseStatus; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.NoHandlerFoundException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; @ControllerAdvice public class GlobalExceptionHandler extends BaseGlobalExceptionHandler {       //比如404的异常就会被这个方法捕获    @ExceptionHandler(NoHandlerFoundException.class)     @ResponseStatus(HttpStatus.NOT_FOUND)      public ModelAndView handle404Error(HttpServletRequest req, HttpServletResponse rsp, Exception e) throws Exception {         return handleError(req, rsp, e, "error-front", HttpStatus.NOT_FOUND);      }       //500的异常会被这个方法捕获    @ExceptionHandler(Exception.class)      @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)    public ModelAndView handleError(HttpServletRequest req, HttpServletResponse rsp, Exception e) throws Exception {        return handleError(req, rsp, e, "error-front", HttpStatus.INTERNAL_SERVER_ERROR);    }       //TODO 你也可以再写一个方法来捕获你的自定义异常    //TRY NOW!!!      @Override     public Logger getLogger() {         return LoggerFactory.getLogger(GlobalExceptionHandler.class);     }    }

以上就三种处理方式，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。