作者： BNDong\
链接： https://www.cnblogs.com/bndon...
前言
在启动利用时会发现在控制台打印的日志中呈现了两个门路为 {[/error]} 的拜访地址，当零碎中发送异样谬误时，Spring Boot 会依据申请形式别离跳转到以 JSON 格局或以界面显示的 /error 地址中显示错误信息。
2018-12-18 09:36:24.627 INFO 19040 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" ...2018-12-18 09:36:24.632 INFO 19040 --- [ main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" ...Spring Boot 根底就不介绍了，举荐下这个实战教程：
https://github.com/javastacks...
默认异样解决
应用 AJAX 形式申请时返回的 JSON 格局错误信息。
{ "timestamp": "2018-12-18T01:50:51.196+0000", "status": 404, "error": "Not Found", "message": "No handler found for GET /err404", "path": "/err404"}应用浏览器申请时返回的错误信息界面。
自定义异样解决
引入依赖
<dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.54</version></dependency><dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-freemarker</artifactId></dependency>fastjson 是 JSON 序列化依赖， spring-boot-starter-freemarker 是一个模板引擎，用于咱们设置谬误输入模板。
减少配置
# 呈现谬误时, 间接抛出异样(便于异样对立解决，否则捕捉不到404)spring.mvc.throw-exception-if-no-handler-found=true# 不要为工程中的资源文件建设映射spring.resources.add-mappings=falsespring: # 呈现谬误时, 间接抛出异样(便于异样对立解决，否则捕捉不到404) mvc: throw-exception-if-no-handler-found: true # 不要为工程中的资源文件建设映射 resources: add-mappings: falseSpring Boot 根底就不介绍了，举荐下这个实战教程：
https://github.com/javastacks...
新建错误信息实体
/** * 信息实体 */public class ExceptionEntity implements Serializable { private static final long serialVersionUID = 1L; private String message; private int code; private String error; private String path; @JSONField(format = "yyyy-MM-dd hh:mm:ss") private Date timestamp = new Date(); public static long getSerialVersionUID() { return serialVersionUID; } public String getMessage() { return message; } public void setMessage(String message) { this.message = message; } public int getCode() { return code; } public void setCode(int code) { this.code = code; } public String getError() { return error; } public void setError(String error) { this.error = error; } public String getPath() { return path; } public void setPath(String path) { this.path = path; } public Date getTimestamp() { return timestamp; } public void setTimestamp(Date timestamp) { this.timestamp = timestamp; }}新建自定义异样
/** * 自定义异样 */public class BasicException extends RuntimeException { private static final long serialVersionUID = 1L; private int code = 0; public BasicException(int code, String message) { super(message); this.code = code; } public int getCode() { return this.code; }}/** * 业务异样 */public class BusinessException extends BasicException { private static final long serialVersionUID = 1L; public BusinessException(int code, String message) { super(code, message); }}BasicException 继承了 RuntimeException ，并在原有的 Message 根底上减少了错误码 code 的内容。而 BusinessException 则是在业务中具体应用的自定义异样类，起到了对不同的异样信息进行分类的作用。
新建 error.ftl 模板文件
地位：/src/main/resources/templates/ 用于显示错误信息
<!DOCTYPE html><html><head> <meta name="robots" content="noindex,nofollow" /> <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no"> <style> h2{ color: #4288ce; font-weight: 400; padding: 6px 0; margin: 6px 0 0; font-size: 18px; border-bottom: 1px solid #eee; } /* Exception Variables */ .exception-var table{ width: 100%; max-width: 500px; margin: 12px 0; box-sizing: border-box; table-layout:fixed; word-wrap:break-word; } .exception-var table caption{ text-align: left; font-size: 16px; font-weight: bold; padding: 6px 0; } .exception-var table caption small{ font-weight: 300; display: inline-block; margin-left: 10px; color: #ccc; } .exception-var table tbody{ font-size: 13px; font-family: Consolas,"Liberation Mono",Courier,"微软雅黑"; } .exception-var table td{ padding: 0 6px; vertical-align: top; word-break: break-all; } .exception-var table td:first-child{ width: 28%; font-weight: bold; white-space: nowrap; } .exception-var table td pre{ margin: 0; } </style></head><body><div class="exception-var"> <h2>Exception Datas</h2> <table> <tbody> <tr> <td>Code</td> <td> ${(exception.code)!} </td> </tr> <tr> <td>Time</td> <td> ${(exception.timestamp?datetime)!} </td> </tr> <tr> <td>Path</td> <td> ${(exception.path)!} </td> </tr> <tr> <td>Exception</td> <td> ${(exception.error)!} </td> </tr> <tr> <td>Message</td> <td> ${(exception.message)!} </td> </tr> </tbody> </table></div></body></html>编写全局异样管制类
/** * 全局异样管制类 */@ControllerAdvicepublic class GlobalExceptionHandler { /** * 404异样解决 */ @ExceptionHandler(value = NoHandlerFoundException.class) @ResponseStatus(HttpStatus.NOT_FOUND) public ModelAndView errorHandler(HttpServletRequest request, NoHandlerFoundException exception, HttpServletResponse response) { return commonHandler(request, response, exception.getClass().getSimpleName(), HttpStatus.NOT_FOUND.value(), exception.getMessage()); } /** * 405异样解决 */ @ExceptionHandler(HttpRequestMethodNotSupportedException.class) public ModelAndView errorHandler(HttpServletRequest request, HttpRequestMethodNotSupportedException exception, HttpServletResponse response) { return commonHandler(request, response, exception.getClass().getSimpleName(), HttpStatus.METHOD_NOT_ALLOWED.value(), exception.getMessage()); } /** * 415异样解决 */ @ExceptionHandler(HttpMediaTypeNotSupportedException.class) public ModelAndView errorHandler(HttpServletRequest request, HttpMediaTypeNotSupportedException exception, HttpServletResponse response) { return commonHandler(request, response, exception.getClass().getSimpleName(), HttpStatus.UNSUPPORTED_MEDIA_TYPE.value(), exception.getMessage()); } /** * 500异样解决 */ @ExceptionHandler(value = Exception.class) public ModelAndView errorHandler (HttpServletRequest request, Exception exception, HttpServletResponse response) { return commonHandler(request, response, exception.getClass().getSimpleName(), HttpStatus.INTERNAL_SERVER_ERROR.value(), exception.getMessage()); } /** * 业务异样解决 */ @ExceptionHandler(value = BasicException.class) private ModelAndView errorHandler (HttpServletRequest request, BasicException exception, HttpServletResponse response) { return commonHandler(request, response, exception.getClass().getSimpleName(), exception.getCode(), exception.getMessage()); } /** * 表单验证异样解决 */ @ExceptionHandler(value = BindException.class) @ResponseBody public ExceptionEntity validExceptionHandler(BindException exception, HttpServletRequest request, HttpServletResponse response) { List<FieldError> fieldErrors = exception.getBindingResult().getFieldErrors(); Map<String,String> errors = new HashMap<>(); for (FieldError error:fieldErrors) { errors.put(error.getField(), error.getDefaultMessage()); } ExceptionEntity entity = new ExceptionEntity(); entity.setMessage(JSON.toJSONString(errors)); entity.setPath(request.getRequestURI()); entity.setCode(HttpStatus.INTERNAL_SERVER_ERROR.value()); entity.setError(exception.getClass().getSimpleName()); response.setStatus(HttpStatus.INTERNAL_SERVER_ERROR.value()); return entity; } /** * 异样解决数据处理 */ private ModelAndView commonHandler (HttpServletRequest request, HttpServletResponse response, String error, int httpCode, String message) { ExceptionEntity entity = new ExceptionEntity(); entity.setPath(request.getRequestURI()); entity.setError(error); entity.setCode(httpCode); entity.setMessage(message); return determineOutput(request, response, entity); } /** * 异样输入解决 */ private ModelAndView determineOutput(HttpServletRequest request, HttpServletResponse response, ExceptionEntity entity) { if (!( request.getHeader("accept").contains("application/json") || (request.getHeader("X-Requested-With") != null && request.getHeader("X-Requested-With").contains("XMLHttpRequest")) )) { ModelAndView modelAndView = new ModelAndView("error"); modelAndView.addObject("exception", entity); return modelAndView; } else { response.setStatus(HttpStatus.INTERNAL_SERVER_ERROR.value()); response.setCharacterEncoding("UTF8"); response.setHeader("Content-Type", "application/json"); try { response.getWriter().write(ResultJsonTools.build( ResponseCodeConstant.SYSTEM_ERROR, ResponseMessageConstant.APP_EXCEPTION, JSONObject.parseObject(JSON.toJSONString(entity)) )); } catch (IOException e) { e.printStackTrace(); } return null; } }}@ControllerAdvice
作用于类上，用于标识该类用于解决全局异样。
@ExceptionHandler
作用于办法上，用于对拦挡的异样类型进行解决。value 属性用于指定具体的拦挡异样类型，如果有多个 ExceptionHandler 存在，则须要指定不同的 value 类型，因为异样类领有继承关系，所以 ExceptionHandler 会首先执行在继承树中靠前的异样类型。
BindException
该异样来自于表单验证框架 Hibernate validation，当字段验证未通过时会抛出此异样。
编写测试 Controller
@RestControllerpublic class TestController { @RequestMapping(value = "err") public void error(){ throw new BusinessException(400, "业务异样错误信息"); } @RequestMapping(value = "err2") public void error2(){ throw new NullPointerException("手动抛出异样信息"); } @RequestMapping(value = "err3") public int error3(){ int a = 10 / 0; return a; }}应用 AJAX 形式申请时返回的 JSON 格局错误信息。
# /err{ "msg": "应用程序异样", "code": -1, "status_code": 0, "data": { "path": "/err", "code": 400, "error": "BusinessException", "message": "业务异样错误信息", "timestamp": "2018-12-18 11:09:00" }}# /err2{ "msg": "应用程序异样", "code": -1, "status_code": 0, "data": { "path": "/err2", "code": 500, "error": "NullPointerException", "message": "手动抛出异样信息", "timestamp": "2018-12-18 11:15:15" }}# /err3{ "msg": "应用程序异样", "code": -1, "status_code": 0, "data": { "path": "/err3", "code": 500, "error": "ArithmeticException", "message": "/ by zero", "timestamp": "2018-12-18 11:15:46" }}# /err404{ "msg": "应用程序异样", "code": -1, "status_code": 0, "data": { "path": "/err404", "code": 404, "error": "NoHandlerFoundException", "message": "No handler found for GET /err404", "timestamp": "2018-12-18 11:16:11" }}应用浏览器申请时返回的错误信息界面。
示例代码：https://github.com/BNDong/spr...
参考资料：
- 《微服务 分布式架构开发实战》 龚鹏 著
- https://www.jianshu.com/p/1a4...
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