本篇文章主要介紹了java基於spring註解AOP的異常處理的方法,具有一定的參考價值,有興趣的小伙伴們可以參考一下。
一、前言
計畫剛開發的時候,並沒有做好充足的準備。開發到一定程度的時候才會想到還有一些問題沒有解決。就比如說今天我要說的一個問題:異常的處理。寫程式的時候通常都會透過try...catch...finally對異常進行處理,但是我們真的能在寫程式的時候處理掉所有可能發生的異常嗎? 以及發生異常的時候執行什麼邏輯,返回什麼提示訊息,跳到什麼頁面,這些都是要考慮到的。
二、基於@ControllerAdvice(加強的控制器)的例外處理
@ControllerAdvice註解內部使用@ExceptionHandler、@ InitBinder、@ModelAttribute註解的方法應用到所有的@RequestMapping註解的方法。本範例中使用ExceptionHandler應用到所有@RequestMapping註解的方法,處理發生的例外狀況。
範例程式碼:
import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.http.HttpHeaders; import org.springframework.http.HttpStatus; import org.springframework.http.ResponseEntity; import org.springframework.util.StringUtils; import org.springframework.web.bind.annotation.ControllerAdvice; import org.springframework.web.bind.annotation.ExceptionHandler; import org.springframework.web.bind.annotation.ResponseBody; import com.hjz.exception.ServiceException; import com.hjz.exception.utils.ExceptionUtils; @ResponseBody public class ExceptionAdvice { private static final Logger LOGGER = LoggerFactory.getLogger(ExceptionAdvice.class); /** * 拦截web层异常,记录异常日志,并返回友好信息到前端 * 目前只拦截Exception,是否要拦截Error需再做考虑 * * @param e 异常对象 * @return 异常提示 */ @ExceptionHandler(Exception.class) public ResponseEntity<String> handleException(Exception e) { //不需要再记录ServiceException,因为在service异常切面中已经记录过 if (!(e instanceof ServiceException)) { LOGGER.error(ExceptionUtils.getExcTrace(e)); } HttpHeaders headers = new HttpHeaders(); headers.set("Content-type", "text/plain;charset=UTF-8"); headers.add("icop-content-type", "exception"); String message = StringUtils.isEmpty(e.getMessage()) ? "系统异常!!" : e.getMessage(); return new ResponseEntity<>(message, headers, HttpStatus.OK); } }
如果不起作用,請檢查spring-mvc的配置文件,是否有ControllerAdvice的如下配置
<context:component-scan base-package="com.sishuok.es" use-default-filters="false"> <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/> <context:include-filter type="annotation" expression="org.springframework.web.bind.annotation.ControllerAdvice"/> </context:component-scan>
三、基於AOP的例外處理
1.處理controller層的例外WebExceptionAspect .java
import org.aspectj.lang.annotation.AfterThrowing; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Pointcut; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; import org.springframework.util.StringUtils; import org.springframework.web.context.request.RequestContextHolder; import org.springframework.web.context.request.ServletRequestAttributes; import com.hjz.exception.ServiceException; import com.hjz.exception.utils.ExceptionUtils; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.PrintWriter; /** * web异常切面 * 默认spring aop不会拦截controller层,使用该类需要在spring公共配置文件中注入改bean, * 另外需要配置<aop:aspectj-autoproxy proxy-target-class="true"/> */ @Aspect public class WebExceptionAspect { private static final Logger LOGGER = LoggerFactory.getLogger(WebExceptionAspect.class); @Pointcut("@annotation(org.springframework.web.bind.annotation.RequestMapping)") private void webPointcut() {} /** * 拦截web层异常,记录异常日志,并返回友好信息到前端 * 目前只拦截Exception,是否要拦截Error需再做考虑 * * @param e 异常对象 */ @AfterThrowing(pointcut = "webPointcut()", throwing = "e") public void handleThrowing(Exception e) { //不需要再记录ServiceException,因为在service异常切面中已经记录过 if (!(e instanceof ServiceException)) { LOGGER.error(ExceptionUtils.getExcTrace(e)); } String errorMsg = StringUtils.isEmpty(e.getMessage()) ? "系统异常" : e.getMessage(); writeContent(errorMsg); } /** * 将内容输出到浏览器 * * @param content 输出内容 */ private void writeContent(String content) { HttpServletResponse response = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getResponse(); response.reset(); response.setCharacterEncoding("UTF-8"); response.setHeader("Content-Type", "text/plain;charset=UTF-8"); response.setHeader("icop-content-type", "exception"); PrintWriter writer = null; try { writer = response.getWriter(); } catch (IOException e) { e.printStackTrace(); } writer.print(content); writer.flush(); writer.close(); } }
2.處理service層的例外ServiceExceptionAspect .java
##
import org.aspectj.lang.JoinPoint; import org.aspectj.lang.annotation.AfterThrowing; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Pointcut; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.stereotype.Component; import org.springframework.util.StringUtils; import com.hjz.exception.ServiceException; import com.hjz.exception.utils.ExceptionUtils; @Aspect public class ServiceExceptionAspect { private static final Logger LOGGER = LoggerFactory.getLogger(ServiceExceptionAspect.class); /** * @within(org.springframework.stereotype.Service),拦截带有 @Service 注解的类的所有方法 * @annotation(org.springframework.web.bind.annotation.RequestMapping),拦截带有@RquestMapping的注解方法 */ @Pointcut("@within(org.springframework.stereotype.Service) && execution(public * *(..))") private void servicePointcut() {} /** * 拦截service层异常,记录异常日志,并设置对应的异常信息 * 目前只拦截Exception,是否要拦截Error需再做考虑 * * @param e 异常对象 */ @AfterThrowing(pointcut = "servicePointcut()", throwing = "e") public void handle(JoinPoint point, Exception e) { LOGGER.error(ExceptionUtils.getExcTrace(e)); String signature = point.getSignature().toString(); String errorMsg = getMessage(signature) == null ? (StringUtils.isEmpty(e.getMessage()) ? "服务异常" : e.getMessage()) : getMessage(signature); throw new ServiceException(errorMsg, e); } /** * 获取方法签名对应的提示消息 * * @param signature 方法签名 * @return 提示消息 */ private String getMessage(String signature) { return null; } }# 3.使用方式,在spring的公共設定檔中加入如下配置:
<aop:aspectj-autoproxy proxy-target-class="true" /> <bean class="com.hjz.exception.aspect.ServiceExceptionAspect" /> <bean class="com.hjz.exception.aspect.WebExceptionAspect" />或自訂一個註冊類,ServiceExceptionAspect.java和WebExceptionAspect.java都加入@Component註解
import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.EnableAspectJAutoProxy; /** * 异常相关bean注册类 */ @Configuration @EnableAspectJAutoProxy @ComponentScan("com.hjz.exception.aspect") public class ExceptionConfig { }
r
@Aspect @Component public class WebExceptionAspect { .......... } @Aspect @Component public class ServiceExceptionAspect { ......... }
@within(org.springframework.stereotype.Service),攔截所有帶有@Service 註解的類別的方法@annotation(org.springframework.web.bind.annotation.RequestMapping ),攔截帶有@RquestMapping的註解方法
五、測試