springmvc全局异常处理

冷不防 2022-05-23 10:08 180阅读 0赞

需求：在SpringMVC中实现全局异常捕获解析以及处理并且返回json状态码

需求分析解决：

1、进入Spring-MVC配置文件配置全局异常处理

1.  ``
2.  `<bean id="exceptionResolver" class="com.xxx.resolver.CustomExceptionResolver"></bean>`

2、定义全局异常处理类

1.  `import java.io.IOException;`
2.  ``
3.  `import javax.servlet.http.HttpServletRequest;`
4.  `import javax.servlet.http.HttpServletResponse;`
5.  ``
6.  `import org.slf4j.Logger;`
7.  `import org.slf4j.LoggerFactory;`
8.  `import org.springframework.http.HttpStatus;`
9.  `import org.springframework.http.MediaType;`
10. `import org.springframework.web.servlet.HandlerExceptionResolver;`
11. `import org.springframework.web.servlet.ModelAndView;`
12. ``
13. `import com.xxx.bean.Result;`
14. `import com.xxx.excption.CustomException;`
15. `import com.xxx.util.ResultUtils;`
16. ``
17. `/**`
18. `* 全局异常处理器`
19. `* @author CatalpaFlat`
20. `*/`
21. `public class CustomExceptionResolver implements HandlerExceptionResolver{`
22. ``
23. `/**日志log*/`
24. `private static Logger log = LoggerFactory.getLogger(CustomExceptionResolver.class);`
25. ``
26. `//系统抛出的异常`
27. `@Override`
28. `public ModelAndView resolveException(HttpServletRequest request,`
29. `HttpServletResponse response, Object handler, Exception ex) {`
30. `//handler就是处理器适配器要执行的Handler对象(只有method)`
31. `//解析出异常类型。`
32. `/* 使用response返回 */`
33. `response.setStatus(HttpStatus.OK.value()); //设置状态码`
34. `response.setContentType(MediaType.APPLICATION_JSON_VALUE); //设置ContentType`
35. `response.setCharacterEncoding("UTF-8"); //避免乱码`
36. `response.setHeader("Cache-Control", "no-cache, must-revalidate");`
37. `//如果该 异常类型是系统 自定义的异常，直接取出异常信息。`
38. `CustomException customException=null;`
39. `try {`
40. `if(ex instanceof CustomException){`
41. `customException = (CustomException)ex;`
42. `//错误信息`
43. `response.getWriter().write(ResultUtils.error(customException.getCode(),ex.getMessage()).toString());`
44. `}else`
45. `response.getWriter().write(ResultUtils.error(-1,ex.getMessage()).toString());`
46. `} catch (IOException e) {`
47. `log.error("与客户端通讯异常:"+ e.getMessage(), e);`
48. `e.printStackTrace();`
49. `}`
50. `ModelAndView modelAndView=new ModelAndView();`
51. ``
52. `return modelAndView;`
53. `}`
54. ``
55. `}`

3、自定义异常类 CustomException

1.  ``
2.  `import com.xxx.enums.ResultEnum;`
3.  ``
4.  `/**`
5.  `* 自定义异常类型`
6.  `* @author CatalpaFlat`
7.  `*/`
8.  `public class CustomException extends Exception {`
9.  ``
10. `private Integer code;`
11. `public CustomException(){}`
12. ``
13. `public CustomException(ResultEnum resultEnum) {`
14. `super((resultEnum.getMsg()));`
15. `this.code = resultEnum.getCode();`
16. `}`
17. ``
18. ``
19. `public Integer getCode() {`
20. `return code;`
21. `}`
22. ``
23. `public void setCode(Integer code) {`
24. `this.code = code;`
25. `}`
26. ``
27. `}`

4、定义Http响应json类

1.  `/** `
2.  `* http请求返回的最外层`
3.  `* Created by CatalpaFlat`
4.  `* on 2017/4/12.`
5.  `*/`
6.  `public class Result<T> {`
7.  ``
8.  `private Integer code;`
9.  ``
10. `private String msg;`
11. ``
12. `private T data;`
13. ``
14. `public Integer getCode() {`
15. `return code;`
16. `}`
17. ``
18. `public void setCode(Integer code) {`
19. `this.code = code;`
20. `}`
21. ``
22. `public String getMsg() {`
23. `return msg;`
24. `}`
25. ``
26. `public void setMsg(String msg) {`
27. `this.msg = msg;`
28. `}`
29. ``
30. `public T getData() {`
31. `return data;`
32. `}`
33. ``
34. `public void setData(T data) {`
35. `this.data = data;`
36. `}`
37. ``
38. `@Override`
39. `public String toString() {`
40. `return "{\"code\": "+code+",\"msg\": \""+msg+"\",\"data\": "+data+"}";`
41. `}`
42. ``
43. `}`

5、定义http返回json的ResulUtils

1.  ``
2.  `import com.xxx.bean.Result;`
3.  `/** `
4.  `* http请求返回success以及error方法封装`
5.  `* Created by CatalpaFlat`
6.  `* on 2017/4/12.`
7.  `*/`
8.  publicclassResultUtils\{ 
9.  ``
10. ``
11. `private static final String SUCCESS_MSG = "成功";`
12. ``
13. `/**`
14. `* http回调成功`
15. `* @param object`
16. `* @return`
17. `*/`
18. `public static Result success(Object object){`
19. `Result result = new Result();`
20. `result.setCode(1);`
21. `result.setMsg(SUCCESS_MSG);`
22. `result.setData(object);`
23. `return result;`
24. `}`
25. ``
26. `/**`
27. `* 无object返回`
28. `* @return`
29. `*/`
30. `public static Result success(){`
31. `return success(null);`
32. `}`
33. ``
34. `/**`
35. `* http回调错误`
36. `* @param code`
37. `* @param msg`
38. `* @return`
39. `*/`
40. `public static Result error(Integer code,String msg){`
41. `Result result = new Result();`
42. `result.setCode(code);`
43. `result.setMsg(msg);`
44. `return result;`
45. `}`
46. ``
47. `}`

6、定义异常类型枚举 ResultEnum

1.  `/**`
2.  `* 枚举定义异常类型以及相对于的错误信息`
3.  `* 有助于返回码的唯一性`
4.  `* Created by CatalpaFlat`
5.  `* on 2017/4/12.`
6.  `*/`
7.  `public enum ResultEnum {`
8.  ``
9.  
10. `UNKONW_ERROR(-1,"未知错误"),`
11. `SUCCESS(0,"成功"),`
12. `TEST_ERRORR(100,"测试异常")`;
13. 
14. privateInteger code;
15. `private String msg;`
16. ``
17. `ResultEnum(Integer code,String msg){`
18. `this.code = code;`
19. `this.msg = msg;`
20. `}`
21. ``
22. `public Integer getCode() {`
23. ``
24. `return code;`
25. `}`
26. ``
27. `public String getMsg() {`
28. `return msg;`
29. `}`
30. `}`

7、测试 TestController

1.  `@Controller`
2.  `@RequestMapping("/teco")`
3.  `public class TestController {`
4.  `@RequestMapping(value = "/testexc",method = RequestMethod.GET)`
5.  `@ResponseBody`
6.  `public void testException() throws CustomException{`
7.  `throw new CustomException(ResultEnum.TEST_ERRORR);`
8.  `}`
9.  `}`

8、测试接口json返回

![SouthEast][]

[SouthEast]: /images/20220523/76c129c24b6143d7ade8822f8e075d95.png