SpringBoot：轻松搞定全局异常处理+错误码枚举+JSR303校验

2022-12-11 12:40:54

SpringBoot实战：全局异常处理+错误码枚举+JSR303校验

1. 全局异常处理的必要性

在SpringBoot项目中，如果不进行全局异常处理，一旦业务层或控制器中发生异常，系统将直接抛出500错误页面，这对用户体验和项目维护都十分不利。

2. SpringBoot全局异常处理

为了解决上述问题，我们需要在SpringBoot项目中添加全局异常处理功能。具体步骤如下：

创建一个新的类来处理异常，如GlobalExceptionHandler：

@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(Exception.class)
    public ResponseEntity<Object> handleException(Exception ex, HttpServletRequest request) {
        // 异常处理逻辑
        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(ex.getMessage());
    }
}

在SpringBoot启动类上添加@ControllerAdvice注解并注册为Spring Bean：

@SpringBootApplication
@ControllerAdvice
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

3. 错误码枚举

在实际开发中，我们经常需要返回特定的错误码以标识不同的异常类型。因此，我们可以创建一个错误码枚举类，如ErrorCodeEnum：

public enum ErrorCodeEnum {

    PARAM_ERROR(1001, "参数错误"),
    RESOURCE_NOT_FOUND(1002, "资源不存在"),
    PERMISSION_DENIED(1003, "权限不足");

    private int code;
    private String message;

    ErrorCodeEnum(int code, String message) {
        this.code = code;
        this.message = message;
    }

    public int getCode() {
        return code;
    }

    public String getMessage() {
        return message;
    }
}

4. SpringBoot JSR303校验

SpringBoot支持JSR303校验，我们可以使用它来对请求参数进行校验。步骤如下：

在实体类上添加JSR303校验注解，如@NotNull、@Size、@Pattern等：

public class User {

    @NotNull
    private String name;

    @Size(min = 6, max = 18)
    private String password;

    @Pattern(regexp = "^[a-zA-Z0-9_-]+@[a-zA-Z0-9_-]+(\\.[a-zA-Z0-9_-]+)+public class User {

    @NotNull
    private String name;

    @Size(min = 6, max = 18)
    private String password;

    @Pattern(regexp = "^[a-zA-Z0-9_-]+@[a-zA-Z0-9_-]+(\\.[a-zA-Z0-9_-]+)+$")
    private String email;
}
quot;)
    private String email;
}

在控制器方法上添加@Valid注解，Spring会自动对请求参数进行校验：

@PostMapping("/register")
public String register(@Valid User user) {
    // 处理注册逻辑
}

示例代码

// User.java
public class User {

    @NotNull
    private String name;

    @Size(min = 6, max = 18)
    private String password;

    @Pattern(regexp = "^[a-zA-Z0-9_-]+@[a-zA-Z0-9_-]+(\\.[a-zA-Z0-9_-]+)+// User.java
public class User {

    @NotNull
    private String name;

    @Size(min = 6, max = 18)
    private String password;

    @Pattern(regexp = "^[a-zA-Z0-9_-]+@[a-zA-Z0-9_-]+(\\.[a-zA-Z0-9_-]+)+$")
    private String email;
}

// GlobalExceptionHandler.java
@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(Exception.class)
    public ResponseEntity<Object> handleException(Exception ex, HttpServletRequest request) {
        if (ex instanceof BusinessException) {
            BusinessException businessException = (BusinessException) ex;
            return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(ErrorCodeEnum.PARAM_ERROR);
        } else {
            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(ErrorCodeEnum.INTERNAL_SERVER_ERROR);
        }
    }
}

// UserController.java
@RestController
public class UserController {

    @PostMapping("/register")
    public String register(@Valid User user) {
        // 处理注册逻辑
        return "注册成功";
    }
}
quot;)
    private String email;
}

// GlobalExceptionHandler.java
@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(Exception.class)
    public ResponseEntity<Object> handleException(Exception ex, HttpServletRequest request) {
        if (ex instanceof BusinessException) {
            BusinessException businessException = (BusinessException) ex;
            return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(ErrorCodeEnum.PARAM_ERROR);
        } else {
            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(ErrorCodeEnum.INTERNAL_SERVER_ERROR);
        }
    }
}

// UserController.java
@RestController
public class UserController {

    @PostMapping("/register")
    public String register(@Valid User user) {
        // 处理注册逻辑
        return "注册成功";
    }
}