Exception Handler Java

Exception Handler Java.java

3 steps:
1. create custom errors and sxtend from `RuntimeException`
2. create a global Exception Handler
3. directly throw the exception from anywhere

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@ResponseStatus(HttpStatus.BAD_REQUEST)
public class BadReq extends RuntimeException {

    public final HttpStatus hCode = HttpStatus.BAD_REQUEST;

    public BadReq() {
        super("BAD_REQUEST !");
    }

    public BadReq(String msg) {
        super(msg);
    }
}
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@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(BadReq.class)
    public ResponseEntity<Object> handleBadReqException(BadReq ex) {
        Map<String, Object> res = new HashMap<>(){{
            put("status_code", ex.hCode.value());
            put("error", ex.getMessage());
        }};
        return ResponseEntity.status(ex.hCode).body(res);
    }

    // @ExceptionHandler(Exception.class)
    // public ResponseEntity<Object> handleResourceNotFoundException(Exception ex) {
    //     Map<String, Object> res = new HashMap<>(){{
    //         put("status_code", HttpStatus.INTERNAL_SERVER_ERROR.value());
    //         put("error", ex.getMessage());
    //     }};
    //     return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(res);
    // }

    @Getter
    public static class ErrorResponse {
        private final String message;

        public ErrorResponse(String message) {
            this.message = message;
        }
    }
}

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throw new BadReq("`id` is missing from request");

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;

@ResponseStatus(HttpStatus.BAD_REQUEST)
public class BadReq extends RuntimeException {

public final HttpStatus hCode = HttpStatus.BAD_REQUEST;

public BadReq() {
    super("BAD_REQUEST !");
}

public BadReq(String msg) {
    super(msg);
}

}

@ControllerAdvice
public class GlobalExceptionHandler {

@ExceptionHandler(ServerError.class)
public ResponseEntity<Object> handleServerError(ServerError ex) {
    Map<String, Object> res = new HashMap<>(){{
        put("status_code", ex.hCode.value());
        put("error", ex.getMessage());
    }};
    return ResponseEntity.status(ex.hCode).body(res);
}

@ExceptionHandler(BadReq.class)
public ResponseEntity<Object> handleBadReqException(BadReq ex) {
    Map<String, Object> res = new HashMap<>(){{
        put("status_code", ex.hCode.value());
        put("error", ex.getMessage());
    }};
    return ResponseEntity.status(ex.hCode).body(res);
}

@ExceptionHandler(Exception.class)
public ResponseEntity<Object> handleResourceNotFoundException(Exception ex) {
    Map<String, Object> res = new HashMap<>(){{
        put("status_code", HttpStatus.INTERNAL_SERVER_ERROR.value());
        put("error", ex.getMessage());
    }};
    return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(res);
}

@Getter
public static class ErrorResponse {
    private final String message;

    public ErrorResponse(String message) {
        this.message = message;
    }
}

}