SpringBoot框架实现邮件发送（上）
SpringBoot框架实现邮件发送（下）
@ControllerAdvice注解的使用
Spring Cache的详细使用（Redis）
Java中获取控制台输出的数据
- Spring Boot的学习笔记目录
- 前言
- 一、StringWriter类和PrintWriter类
- 二、使用步骤
前言
最近由于学习spring boot日志存储到本地的时候，突然想到如果运行报错的话，抛出的异常只显示在控制台上，怎么样获取这个抛出的异常信息就无从下手，搜索几番后才明白，特意写下这个笔记记录一下。
一、StringWriter类和PrintWriter类
StringWriter类：一种字符流，它在字符串缓冲区中收集其输出，然后可用于构造字符串。
PrintWriter类： 基于字符的输出流，可以输出字符或字符串整型等数据。输出的目标可以是磁盘文件、其他输出流。
获取抛出异常的字符串
代码如下（示例）：
public class ExceptionUtils {
public static String getMessage(Exception e){
StringWriter stringWriter =null;
PrintWriter printWriter = null;
try {
stringWriter = new StringWriter();
printWriter = new PrintWriter(stringWriter);
// 将出错的栈信息输出到printWriter中
e.printStackTrace(printWriter);
printWriter.flush();
stringWriter.flush();
}finally {
if (stringWriter!=null){
try {
stringWriter.close();
}catch (IOException ioException){
ioException.printStackTrace();
}
}
if (printWriter!=null){
printWriter.close();
}
}
return stringWriter.toString();
}
}
测试
代码如下（示例）：
@ControllerAdvice
@Slf4j
public class GlobalExceptionHandler {
// 指定出行什么异常就执行这个方法
@ExceptionHandler(Exception.class)
@ResponseBody // 为了返回数据
public R error(Exception e){
log.error(ExceptionUtils.getMessage(e));
e.printStackTrace();
return R.error(e.getMessage()).message("全局异常处理类："+e.getMessage());
}
}
@RequestMapping("/test")
@RestController
public class TestController {
@GetMapping()
public String str(){
int i = 10/0;
return "str";
}
}
结果:
|ERROR |http-nio-8081-exec-1 |GlobalExceptionHandler.java:33 |com.atguigu.servicebase.exceptionHandler.GlobalExceptionHandler |java.lang.ArithmeticException: / by zero at com.atguigu.eduservice.controller.TestController.str(TestController.java:16) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:888) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1579) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:748)
