在 java web开发过程中，难免会有一些系统异常或人为产生一些异常。在 RESTful springboot 项目中如何优雅的处理？
分析：在RESTful 风格的springboot 项目中，返回的都是 body 对象，所以定义一个结果基类，其中包含 status,message,data(请求方法的返回结果),是比较合适的。
如果定义多个异常类进行处理，会比较麻烦。比如StudentNotExistsException、StudentExistsException。。。等，并且不能指定错误码，不方便前端根据错误码进行处理。
说明：一般的spring mvc模型处理流程如下
一般controller层 -> Service层 -> Dao层。
1.controller层，接受请求，进行分页，DTO对象封装操作。
2.service层，执行逻辑，控制并发，事务。
3.Dao层，与数据库交互。
使用一个学生表的处理进行说明：
1、定义常见的错误枚举 StudentExceptionEnum
public enum StudentExceptionEnum { STUDENT_NOT_EXIST(1004,"学生不存在，请确认后再查"), STUDENT_EXIST(1005,"学生已存在"); private Integer status; private String comment; StudentExceptionEnum(Integer status, String comment) { this.status = status; this.comment = comment; } public Integer getStatus() { return status; } public void setStatus(Integer status) { this.status = status; } public String getComment() { return comment; } public void setComment(String comment) { this.comment = comment; }}2 定义一个基本的处理结果类 RequestResult
@Datapublic class RequestResult { private String message; private Integer status; private Object data; public RequestResult(String message, Integer status, Object data) { this.message = message; this.status = status; this.data = data; } public RequestResult(String message, Integer status) { this.message = message; this.status = status; } public RequestResult(String message, StudentExceptionEnum requestExceptionEnum) { this.message = message; this.status = requestExceptionEnum.getStatus(); } public RequestResult() { status = 200; message = "ok"; } public static RequestResult OK(Object data) { RequestResult result = new RequestResult(); result.setData(data); return result; } public static RequestResult EXCEPTION(String message, Integer status) { return new RequestResult(message, status); } public static RequestResult EXCEPTION(String message, StudentExceptionEnum requestExceptionEnum) { return new RequestResult(message, requestExceptionEnum); }}3 实体类 Student
@Datapublic class Student implements Serializable{ private String id; private String nickname; private String name; private int age; private String sex; private String address; @Override public String toString() { return ToStringBuilder.reflectionToString(this); }}4 处理请求，添加学生，nickname 必填项。此处只显示 Service 片段代码
@Override public RequestResult addStudent(Student student) { if (studentDao.queryIdByNickname(student.getNickname()) == null) { studentDao.addStudent(student); System.out.println("添加成功"); student = studentDao.queryByNickname(student.getNickname()); return RequestResult.OK(student); } else { return RequestResult.EXCEPTION("用户" + student.getNickname() + "已存在", StudentExceptionEnum.STUDENT_EXIST); } }5 此时，已经完成了基本的处理情况。下面就进行基本的测试了
5.1 添加一个新同学信息
5.2 再次添加让其出现异常测试
二、到此基本已大功告成，但是，对于基本的运行时异常没有处理，直接返回给前端会很不友好。所以要定义一个全局的 RuntimeException 异常处理类。
此处需要使用的关键标注： @ExceptionHandler
用法有两种 1）在处理请求的 Controller 中添加 @ExceptionHandler，此时该方法只会处理该 Controller 抛出的异常。
2）将其用在全局的异常处理类中，全局异常处理类需要使用 @RestControllerAdvice 或 @ControllerAdvice 标记
我们需要处理全局的 RuntimeException，所以我们使用第二种方法。当然，这样处理是为了客户友好型，我们还是要处理这种错误，怎么办？就需要将错误的信息记录下来，方便以后分析处理。此处使用 logger 进行记录。代码如下
@RestControllerAdvicepublic class BaseExceptionHandler { private static Logger logger = LoggerFactory.getLogger(BaseExceptionHandler.class); @ExceptionHandler(value = RuntimeException.class) public RequestResult exceptionHandler(HttpServletRequest request,Exception e) { logError(request,e); return RequestResult.EXCEPTION("内部处理异常，工程师正在抓紧抢修，请稍后再来...",500); } public static void logError(HttpServletRequest request, Exception e) { logger.error("请求地址：" + request.getRequestURL()); logger.error("请求方法：" + request.getMethod()); logger.error("请求IP：" + getRemoteIp(request)); logger.error("错误详情："); StackTraceElement[] error = e.getStackTrace(); for (StackTraceElement stackTraceElement : error) { logger.error(stackTraceElement.toString()); } } public static String getRemoteIp(HttpServletRequest request) { String ip = request.getHeader("X-Forwarded-For"); if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { ip = request.getHeader("Proxy-Client-IP"); } if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { ip = request.getHeader("WL-Proxy-Client-IP"); } if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { ip = request.getHeader("HTTP_CLIENT_IP"); } if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { ip = request.getHeader("HTTP_X_FORWARDED_FOR"); } if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) { ip = request.getRemoteAddr(); } } else if (ip.length() > 15) { String[] ips = ip.split(","); for (int index = 0; index < ips.length; index++) { String strIp = (String) ips[index]; if (!("unknown".equalsIgnoreCase(strIp))) { ip = strIp; break; } } } return ip; }}进行测试看是否生效：
修改添加学生信息代码如下：
public RequestResult addStudent(Student student) { int a = 1/0; if (studentDao.queryIdByNickname(student.getNickname()) == null) { studentDao.addStudent(student); System.out.println("添加成功"); student = studentDao.queryByNickname(student.getNickname()); return RequestResult.OK(student); } else { return RequestResult.EXCEPTION("用户'" + student.getNickname() + "'已存在", StudentExceptionEnum.STUDENT_EXIST); } }进行测试
后台打印错误信息
2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : 请求地址：http://localhost:8080/demo1/student2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : 请求方法：POST2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : 请求IP：0:0:0:0:0:0:0:12018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : 错误详情：2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : com.huitong.demo.service.StudentService.addStudent(StudentService.java:71)2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : com.huitong.demo.controller.StudentController.addStudent(StudentController.java:38)2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : java.lang.reflect.Method.invoke(Method.java:498)2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:870)2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:776)2018-03-26 17:01:19.125 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)2018-03-26 17:01:19.129 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)2018-03-26 17:01:19.129 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)2018-03-26 17:01:19.129 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:978)2018-03-26 17:01:19.129 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:881)2018-03-26 17:01:19.129 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : javax.servlet.http.HttpServlet.service(HttpServlet.java:661)2018-03-26 17:01:19.129 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:855)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : javax.servlet.http.HttpServlet.service(HttpServlet.java:742)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:123)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)2018-03-26 17:01:19.130 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)2018-03-26 17:01:19.131 ERROR 9136 --- [nio-8080-exec-2] c.h.d.controller.BaseExceptionHandler : java.lang.Thread.run(Thread.java:745)2018-03-26 17:01:19.133 WARN 9136 --- [nio-8080-exec-2] .m.m.a.ExceptionHandlerExceptionResolver : Resolved exception caused by Handler execution: java.lang.ArithmeticException: / by zero
总结
以上所述是小编给大家介绍的springboot 错误处理小结，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对武林网网站的支持！