SpringBoot統(tǒng)一返回JSON格式實(shí)現(xiàn)方法詳解

更新時(shí)間：2023年02月03日 11:22:47 作者：編程指南針

這篇文章主要介紹了SpringBoot統(tǒng)一返回JSON格式實(shí)現(xiàn)方法，文中通過示例代碼介紹的非常詳細(xì)，對(duì)大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價(jià)值，需要的朋友們下面隨著小編來一起學(xué)習(xí)吧

其實(shí)本沒有沒打算寫這篇的，但還是要寫一下寫這篇博客的起因是因?yàn)?，現(xiàn)在呆著的這家公司居然沒有統(tǒng)一的API返回格式?，詢問主管他居然告訴我用HTTP狀態(tài)碼就夠用了（fxxk），天哪HTTP狀態(tài)碼真的夠用嗎？

在仔細(xì)的閱讀了項(xiàng)目源碼后發(fā)現(xiàn)，在API請(qǐng)求的是居然沒有業(yè)務(wù)異常（黑人問好）。好吧居然入坑了只能遵照項(xiàng)目風(fēng)格了，懶得吐槽了。

因?yàn)轫?xiàng)目已經(jīng)開發(fā)了半年多了,要是全部接口都做修改工作量還是挺大的,只能用這種無侵入式的方案來解決.

項(xiàng)目源代碼:https://github.com/469753862/galaxy-blogs/tree/master/code/responseResult

定義JSON格式

定義返回JSON格式

后端返回給前端一般情況下使用JSON格式,定義如下

{
    "code": 200,
    "message": "OK",
    "data": {
    }
}

code:返回狀態(tài)碼
message:返回信息的描述
data:返回值

定義JavaBean字段

定義狀態(tài)碼枚舉類

@ToString
@Getter
public enum ResultStatus {
    SUCCESS(HttpStatus.OK, 200, "OK"),
    BAD_REQUEST(HttpStatus.BAD_REQUEST, 400, "Bad Request"),
    INTERNAL_SERVER_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, 500, "Internal Server Error"),;
    /** 返回的HTTP狀態(tài)碼,  符合http請(qǐng)求 */
    private HttpStatus httpStatus;
    /** 業(yè)務(wù)異常碼 */
    private Integer code;
    /** 業(yè)務(wù)異常信息描述 */
    private String message;
    ResultStatus(HttpStatus httpStatus, Integer code, String message) {
        this.httpStatus = httpStatus;
        this.code = code;
        this.message = message;
    }
}

狀態(tài)碼和信息以及http狀態(tài)碼就能一一對(duì)應(yīng)了便于維護(hù),有同學(xué)有疑問了為什么要用到http狀態(tài)碼呀,因?yàn)槲乙嫒蓓?xiàng)目以前的代碼,沒有其他原因,當(dāng)然其他同學(xué)不喜歡http狀態(tài)碼的可以吧源碼中HttpStatus給刪除了

定義返回體類

@Getter
@ToString
public class Result<T> {
    /** 業(yè)務(wù)錯(cuò)誤碼 */
    private Integer code;
    /** 信息描述 */
    private String message;
    /** 返回參數(shù) */
    private T data;
    private Result(ResultStatus resultStatus, T data) {
        this.code = resultStatus.getCode();
        this.message = resultStatus.getMessage();
        this.data = data;
    }
    /** 業(yè)務(wù)成功返回業(yè)務(wù)代碼和描述信息 */
    public static Result<Void> success() {
        return new Result<Void>(ResultStatus.SUCCESS, null);
    }
    /** 業(yè)務(wù)成功返回業(yè)務(wù)代碼,描述和返回的參數(shù) */
    public static <T> Result<T> success(T data) {
        return new Result<T>(ResultStatus.SUCCESS, data);
    }
    /** 業(yè)務(wù)成功返回業(yè)務(wù)代碼,描述和返回的參數(shù) */
    public static <T> Result<T> success(ResultStatus resultStatus, T data) {
        if (resultStatus == null) {
            return success(data);
        }
        return new Result<T>(resultStatus, data);
    }
    /** 業(yè)務(wù)異常返回業(yè)務(wù)代碼和描述信息 */
    public static <T> Result<T> failure() {
        return new Result<T>(ResultStatus.INTERNAL_SERVER_ERROR, null);
    }
    /** 業(yè)務(wù)異常返回業(yè)務(wù)代碼,描述和返回的參數(shù) */
    public static <T> Result<T> failure(ResultStatus resultStatus) {
        return failure(resultStatus, null);
    }
    /** 業(yè)務(wù)異常返回業(yè)務(wù)代碼,描述和返回的參數(shù) */
    public static <T> Result<T> failure(ResultStatus resultStatus, T data) {
        if (resultStatus == null) {
            return new Result<T>(ResultStatus.INTERNAL_SERVER_ERROR, null);
        }
        return new Result<T>(resultStatus, data);
    }
}

因?yàn)槭褂脴?gòu)造方法進(jìn)行創(chuàng)建對(duì)象太麻煩了,我們使用靜態(tài)方法來創(chuàng)建對(duì)象這樣簡單明了

Result實(shí)體返回測(cè)試

@RestController
@RequestMapping("/hello")
public class HelloController {
    private static final HashMap<String, Object> INFO;
    static {
        INFO = new HashMap<>();
        INFO.put("name", "galaxy");
        INFO.put("age", "70");
    }
    @GetMapping("/hello")
    public Map<String, Object> hello() {
        return INFO;
    }
    @GetMapping("/result")
    @ResponseBody
    public Result<Map<String, Object>> helloResult() {
        return Result.success(INFO);
    }
}

到這里我們已經(jīng)簡單的實(shí)現(xiàn)了統(tǒng)一JSON格式了,但是我們也發(fā)現(xiàn)了一個(gè)問題了,想要返回統(tǒng)一的JSON格式需要返回Result<Object>才可以,我明明返回Object可以了,為什么要重復(fù)勞動(dòng),有沒有解決方法,當(dāng)然是有的啦,下面我們開始優(yōu)化我們的代碼吧

統(tǒng)一返回JSON格式進(jìn)階

全局處理(@RestControllerAdvice)

我?guī)煾到?jīng)常告訴我的一句話:“你就是一個(gè)小屁孩,你遇到的問題都已經(jīng)不知道有多少人遇到過了,你會(huì)想到的問題,已經(jīng)有前輩想到過了.你準(zhǔn)備解決的問題,已經(jīng)有人把坑填了”。是不是很雞湯,是不是很勵(lì)志,讓我對(duì)前輩們充滿著崇拜,事實(shí)上他對(duì)我說的是:“自己去百度”,這五個(gè)大字,其實(shí)這五個(gè)大字已經(jīng)說明上明的B話了,通過不斷的百度和Google發(fā)現(xiàn)了很多的解決方案.

我們都知道使用@ResponseBody注解會(huì)把返回Object序列化成JSON字符串,就先從這個(gè)入手吧,大致就是在序列化前把Object賦值給Result<Object>就可以了,大家可以觀摩org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice和org.springframework.web.bind.annotation.ResponseBody

@ResponseBody繼承類

我們已經(jīng)決定從@ResponseBody注解入手了就創(chuàng)建一個(gè)注解類繼承@ResponseBody,很干凈什么都沒有哈哈,@ResponseResultBody可以標(biāo)記在類和方法上這樣我們就可以跟自由的進(jìn)行使用了

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.METHOD})
@Documented
@ResponseBody
public @interface ResponseResultBody {
}

ResponseBodyAdvice繼承類

@RestControllerAdvice
public class ResponseResultBodyAdvice implements ResponseBodyAdvice<Object> {
    private static final Class<? extends Annotation> ANNOTATION_TYPE = ResponseResultBody.class;
    /**
     * 判斷類或者方法是否使用了 @ResponseResultBody
     */
    @Override
    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        return AnnotatedElementUtils.hasAnnotation(returnType.getContainingClass(), ANNOTATION_TYPE) || returnType.hasMethodAnnotation(ANNOTATION_TYPE);
    }
    /**
     * 當(dāng)類或者方法使用了 @ResponseResultBody 就會(huì)調(diào)用這個(gè)方法
     */
    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
        // 防止重復(fù)包裹的問題出現(xiàn)
        if (body instanceof Result) {
            return body;
        }
        return Result.success(body);
    }
}

RestControllerAdvice返回測(cè)試

@RestController
@RequestMapping("/helloResult")
@ResponseResultBody
public class HelloResultController {
    private static final HashMap<String, Object> INFO;
    static {
        INFO = new HashMap<String, Object>();
        INFO.put("name", "galaxy");
        INFO.put("age", "70");
    }
    @GetMapping("hello")
    public HashMap<String, Object> hello() {
        return INFO;
    }
    /** 測(cè)試重復(fù)包裹 */
    @GetMapping("result")
    public Result<Map<String, Object>> helloResult() {
        return Result.success(INFO);
    }
    @GetMapping("helloError")
    public HashMap<String, Object> helloError() throws Exception {
        throw new Exception("helloError");
    }
    @GetMapping("helloMyError")
    public HashMap<String, Object> helloMyError() throws Exception {
        throw new ResultException();
    }
}

是不是很神奇,直接返回Object就可以統(tǒng)一JSON格式了,就不用每個(gè)返回都返回Result<T>對(duì)象了,直接讓SpringMVC幫助我們進(jìn)行統(tǒng)一的管理,簡直完美

只想看接口哦,helloError和helloMyError是會(huì)直接拋出異常的接口,我好像沒有對(duì)異常返回進(jìn)行統(tǒng)一的處理哦

統(tǒng)一返回JSON格式進(jìn)階

異常處理(@ExceptionHandler))

異常處理,差點(diǎn)把這茬給忘了,這個(gè)異常處理就有很多方法了,先看看我?guī)煾档奶幚矸绞?我剛拿到這個(gè)代碼的時(shí)候很想吐槽,對(duì)異常類的處理這么殘暴的嗎,直接用PrintWriter直接輸出結(jié)果,果然是老師傅,我要是有100個(gè)異常類,不得要寫100個(gè)ifelse了.趕緊改改睡吧

@Configuration
public class MyExceptionHandler implements HandlerExceptionResolver {
    public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response,
                                         Object handler, Exception ex) {
        PrintWriter out = getPrintWrite(response);
        if (ex instanceof XXXException) {
            out.write(JsonUtil.formatJson(ResultEnum.PAY_ERROR.getCode(), ex.getMessage()));
        } else {
            out.write(JsonUtil.formatJson(ResultEnum.FAIL.getCode(), "服務(wù)器異常"));
        }
        if (null != out) {
            out.close();
        }
        return mav;
    }
    private PrintWriter getPrintWrite(HttpServletResponse response) {
        PrintWriter out = null;
        try {
            response.setHeader("Content-type", "text/html;charset=UTF-8");
            response.setCharacterEncoding("UTF-8");
            out = response.getWriter();
        } catch (IOException e) {
            log.error("PrintWriter is exception", e);
        }
        return out;
    }
}

上面的代碼看看還是沒有問題的,別學(xué)過去哦,

異常處理@ResponseStatus(不推薦)

@ResponseStatus用法如下,可用在Controller類和Controller方法上以及Exception類上但是這樣的工作量還是挺大的

@RestController
@RequestMapping("/error")
@ResponseStatus(value = HttpStatus.INTERNAL_SERVER_ERROR, reason = "Java的異常")
public class HelloExceptionController {
    private static final HashMap<String, Object> INFO;
    static {
        INFO = new HashMap<String, Object>();
        INFO.put("name", "galaxy");
        INFO.put("age", "70");
    }
    @GetMapping()
    public HashMap<String, Object> helloError() throws Exception {
        throw new Exception("helloError");
    }
    @GetMapping("helloJavaError")
    @ResponseStatus(value = HttpStatus.INTERNAL_SERVER_ERROR, reason = "Java的異常")
    public HashMap<String, Object> helloJavaError() throws Exception {
        throw new Exception("helloError");
    }
    @GetMapping("helloMyError")
    public HashMap<String, Object> helloMyError() throws Exception {
        throw new MyException();
    }
}
@ResponseStatus(value = HttpStatus.INTERNAL_SERVER_ERROR, reason = "自己定義的異常")
class MyException extends Exception {
}

全局異常處理@ExceptionHandler(推薦)

把ResponseResultBodyAdvice類進(jìn)行改造一下,代碼有點(diǎn)多了

主要參考了org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler#handleException()方法,有空可以看一下

@Slf4j
@RestControllerAdvice
public class ResponseResultBodyAdvice implements ResponseBodyAdvice<Object> {
    private static final Class<? extends Annotation> ANNOTATION_TYPE = ResponseResultBody.class;
    /** 判斷類或者方法是否使用了 @ResponseResultBody */
    @Override
    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        return AnnotatedElementUtils.hasAnnotation(returnType.getContainingClass(), ANNOTATION_TYPE) || returnType.hasMethodAnnotation(ANNOTATION_TYPE);
    }
    /** 當(dāng)類或者方法使用了 @ResponseResultBody 就會(huì)調(diào)用這個(gè)方法 */
    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {
        if (body instanceof Result) {
            return body;
        }
        return Result.success(body);
    }
    /**
     * 提供對(duì)標(biāo)準(zhǔn)Spring MVC異常的處理
     *
     * @param ex      the target exception
     * @param request the current request
     */
    @ExceptionHandler(Exception.class)
    public final ResponseEntity<Result<?>> exceptionHandler(Exception ex, WebRequest request) {
        log.error("ExceptionHandler: {}", ex.getMessage());
        HttpHeaders headers = new HttpHeaders();
        if (ex instanceof ResultException) {
            return this.handleResultException((ResultException) ex, headers, request);
        }
        // TODO: 2019/10/05 galaxy 這里可以自定義其他的異常攔截
        return this.handleException(ex, headers, request);
    }
    /** 對(duì)ResultException類返回返回結(jié)果的處理 */
    protected ResponseEntity<Result<?>> handleResultException(ResultException ex, HttpHeaders headers, WebRequest request) {
        Result<?> body = Result.failure(ex.getResultStatus());
        HttpStatus status = ex.getResultStatus().getHttpStatus();
        return this.handleExceptionInternal(ex, body, headers, status, request);
    }
    /** 異常類的統(tǒng)一處理 */
    protected ResponseEntity<Result<?>> handleException(Exception ex, HttpHeaders headers, WebRequest request) {
        Result<?> body = Result.failure();
        HttpStatus status = HttpStatus.INTERNAL_SERVER_ERROR;
        return this.handleExceptionInternal(ex, body, headers, status, request);
    }
    /**
     * org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler#handleExceptionInternal(java.lang.Exception, java.lang.Object, org.springframework.http.HttpHeaders, org.springframework.http.HttpStatus, org.springframework.web.context.request.WebRequest)
     * <p>
     * A single place to customize the response body of all exception types.
     * <p>The default implementation sets the {@link WebUtils#ERROR_EXCEPTION_ATTRIBUTE}
     * request attribute and creates a {@link ResponseEntity} from the given
     * body, headers, and status.
     */
    protected ResponseEntity<Result<?>> handleExceptionInternal(
            Exception ex, Result<?> body, HttpHeaders headers, HttpStatus status, WebRequest request) {
        if (HttpStatus.INTERNAL_SERVER_ERROR.equals(status)) {
            request.setAttribute(WebUtils.ERROR_EXCEPTION_ATTRIBUTE, ex, WebRequest.SCOPE_REQUEST);
        }
        return new ResponseEntity<>(body, headers, status);
    }
}

到此這篇關(guān)于SpringBoot統(tǒng)一返回JSON格式實(shí)現(xiàn)方法詳解的文章就介紹到這了,更多相關(guān)SpringBoot返回JSON格式內(nèi)容請(qǐng)搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！

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