前言：

项目做前后端分离时，我们会经常提供Json数据给前端，如果有一个统一的Json格式返回工具类，那么将大大提高开发效率和减低沟通成本。
此Json响应工具类，支持带分页信息，支持泛型，支持HttpStatus标准返回码

效果预览：

步入正题：

1. Resp工具类

import java.io.Serializable;
import java.util.Map;

/**
 * @Author: Seifon
 * @Description: Restful统一Json响应对象封装
 * @Date: Created in 9:39 2018/4/10
 */
public class Resp<T> implements Serializable {
    private static final long serialVersionUID = 1L;

    private final static String SUCCESS_CODE = "200";

    /**
     * 返回状态码
     */
    private String status;

    /**
     * 返回消息
     */
    private String message;

    /**
     * 返回内容
     */
    private T data;

    /**
     * 分页信息
     */
    private PageInfo page;

    /**
     * 其他内容
     */
    private Map<String, Object> ext;

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public T getData() {
        return data;
    }

    public void setData(T data) {
        this.data = data;
    }

    public Map<String, Object> getExt() {
        return ext;
    }

    public void setExt(Map<String, Object> ext) {
        this.ext = ext;
    }

    public PageInfo getPage() {
        return page;
    }

    public void setPage(PageInfo page) {
        this.page = page;
    }

    public Resp(){
    	this.status = SUCCESS_CODE;
    	this.message = "SUCCESS";
    }

    public Resp(String status, String message) {
        this.status = status;
        this.message = message;
    }

    public Resp(String status, String message, T data) {
        this.status = status;
        this.message = message;
        this.data = data;
    }

    public Resp(String status, String message, T data, Map<String, Object> ext) {
        this.status = status;
        this.message = message;
        this.data = data;
        this.ext = ext;
    }

    public Resp(String status, String message, T data, PageInfo pageInfo) {
        this.status = status;
        this.message = message;
        this.data = data;
        this.page = pageInfo;
    }

    public Resp(String status, String message, T data, Map<String, Object> ext, PageInfo pageInfo) {
        this.status = status;
        this.message = message;
        this.data = data;
        this.ext = ext;
        this.page = pageInfo;
    }

    public Resp(String status, String message, T data, Long total, Integer pageNo, Integer pageSize){
        PageInfo pageInfo = new PageInfo(total, pageNo, pageSize);
        this.status = status;
        this.message = message;
        this.data = data;
        this.page = pageInfo;
    }

    public Resp(String status, String message, T data, Map<String, Object> ext, Long total, Integer pageNo, Integer pageSize){
        PageInfo pageInfo = new PageInfo(total, pageNo, pageSize);
        this.status = status;
        this.message = message;
        this.data = data;
        this.ext = ext;
        this.page = pageInfo;
    }

    //快速返回成功
    public static <T>Resp success(){
        return new Resp<T>(SUCCESS_CODE,"请求成功",null);
    }

    public static <T>Resp success(T result){
        return new Resp<T>(SUCCESS_CODE,"请求成功",result);
    }

    public static <T>Resp success(String message, T result){
        return new Resp<T>(SUCCESS_CODE,message,result);
    }

    public static <T>Resp success(String message, T result, Map<String, Object> extra){
        return new Resp<T>(SUCCESS_CODE,message,result, extra);
    }

    public static <T>Resp success(T result, Long total, Integer pageNo, Integer pageSize){
        PageInfo pageInfo = new PageInfo(total, pageNo, pageSize);
        return new Resp<T>(SUCCESS_CODE,"请求成功",result, pageInfo);
    }
    
    public static <T>Resp success(T result, Map<String, Object> extra, Long total, Integer pageNo, Integer pageSize){
        PageInfo pageInfo = new PageInfo(total, pageNo, pageSize);
        return new Resp<T>(SUCCESS_CODE,"请求成功",result, extra,pageInfo);
    }

    public static <T>Resp success(String message, T result, Long total, Integer pageNo, Integer pageSize){
        PageInfo pageInfo = new PageInfo(total, pageNo, pageSize);
        return new Resp<T>(SUCCESS_CODE,message,result,pageInfo);
    }

    public static <T>Resp success(String message, T result, Map<String, Object> extra, Long total, Integer pageNo, Integer pageSize){
        PageInfo pageInfo = new PageInfo(total, pageNo, pageSize);
        return new Resp<T>(SUCCESS_CODE,message,result, extra,pageInfo);
    }

    //快速返回失败状态
    public static <T>Resp fail(){
        return new Resp<T>(ErrorCode.SYSTEM_ERROR.getCode(),ErrorCode.SYSTEM_ERROR.getMessage());
    }

    public static <T>Resp fail(T result){
        return new Resp<T>(ErrorCode.SYSTEM_ERROR.getCode(),ErrorCode.SYSTEM_ERROR.getMessage(),result);
    }
    
    public <T>Resp fail(String message, T result){
        return new Resp<T>(ErrorCode.SYSTEM_ERROR.getCode(),message,result);
    }

    public <T>Resp fail(String message, T result, Map<String, Object> extra){
        return new Resp<T>(ErrorCode.SYSTEM_ERROR.getCode(),message,result, extra);
    }

    public static <T>Resp fail(ErrorCode errorCode){
        return new Resp<T>(errorCode.getCode(),errorCode.getMessage());
    }

    public static <T>Resp fail(ErrorCode errorCode, T result){
        return new Resp<T>(errorCode.getCode(),errorCode.getMessage(),result);
    }

    public static <T>Resp fail(ErrorCode errorCode, String message, T result){
        return new Resp<T>(errorCode.getCode(),message,result);
    }

    public static <T>Resp fail(ErrorCode errorCode, String message, T result, Map<String, Object> extra){
        return new Resp<T>(errorCode.getCode(),message,result, extra);
    }

    //快速返回自定义状态码
    public static <T>Resp result(String statusCode, String message){
        return new Resp<T>(statusCode,message);
    }

    public static <T>Resp result(String statusCode, String message, T result){
        return new Resp<T>(statusCode,message,result);
    }

    public static <T>Resp result(String statusCode, String message, T result, Map<String, Object> extra){
        return new Resp<T>(statusCode,message,result, extra);
    }

    public static <T>Resp result(String statusCode, String message, T result, Long total, Integer pageNo, Integer pageSize){
        PageInfo pageInfo = new PageInfo(total, pageNo, pageSize);
        return new Resp<T>(statusCode,message,result, pageInfo);
    }

    public static <T>Resp result(String statusCode, String message, T result, Map<String, Object> extra, Long total, Integer pageNo, Integer pageSize){
        PageInfo pageInfo = new PageInfo(total, pageNo, pageSize);
        return new Resp<T>(statusCode,message,result, extra,pageInfo);
    }

    //快速返回Http状态
    public static <T>Resp httpStatus(HttpStatus httpStatus, String message){
        return result(httpStatus.toString(),message);
    }

    public static <T>Resp httpStatus(HttpStatus httpStatus, String message, T result){
        return result(httpStatus.toString(),message,result);
    }

    public static <T>Resp httpStatus(HttpStatus httpStatus, String message, T result, Map<String, Object> extra){
        return result(httpStatus.toString(),message,result, extra);
    }

    public static <T>Resp httpStatus(HttpStatus httpStatus, String message, T result, Long total, Integer pageNo, Integer pageSize){
        PageInfo pageInfo = new PageInfo(total, pageNo, pageSize);
        return result(httpStatus.toString(),message,result, total, pageNo, pageSize);
    }

    public static <T>Resp httpStatus(HttpStatus httpStatus, String message, T result, Map<String, Object> extra, Long total, Integer pageNo, Integer pageSize){
        PageInfo pageInfo = new PageInfo(total, pageNo, pageSize);
        return result(httpStatus.toString(),message,result, extra, total, pageNo, pageSize);
    }
}

2. PageInfo 用于封装分页信息的

import java.io.Serializable;

/**
 * @Author: Seifon
 * @Description: 分页信息
 * @Date: Created in 9:39 2018/4/10
 */
public class PageInfo implements Serializable{


	private static final long serialVersionUID = 1L;
	/**
	 * 总记录数
	 */
	private Long total;
	/**
	 * 总页数
	 */
	private Long totalPages;
	/**
	 * 当前页
	 */
	private Integer pageNo;
	/**
	 * 页记录数
	 */
	private Integer pageSize;

	public PageInfo(Long total) {
		this.total = total;
	}

	public PageInfo(Long total, Integer pageNo,
                    Integer pageSize) {
		this.total = total;
		this.totalPages = (total - 1) / pageSize + 1;
		this.pageNo = pageNo;
		this.pageSize = pageSize;
	}

	public static PageInfo page(Long total) {
		return new PageInfo(total);
	}

	public static PageInfo page( Long total, Integer pageNo,
                                      Integer pageSize) {
		return new PageInfo(total, pageNo, pageSize);
	}

	public Long getTotal() {
		return total;
	}

	public void setTotal(Long total) {
		this.total = total;
	}

	public Long getTotalPages() {
		return totalPages;
	}

	public void setTotalPages(Long totalPages) {
		this.totalPages = totalPages;
	}

	public Integer getPageNo() {
		return pageNo;
	}

	public void setPageNo(Integer pageNo) {
		this.pageNo = pageNo;
	}

	public Integer getPageSize() {
		return pageSize;
	}

	public void setPageSize(Integer pageSize) {
		this.pageSize = pageSize;
	}
}

4. ErrorCode 用于定义错误码

/**
 * @Author: Seifon
 * @Description: 错误码
 * @Date: Created in 9:39 2018/4/10
 */
public enum ErrorCode {

	SYSTEM_ERROR(500, "系统错误"),
	PARAMETER_CHECK_ERROR(400, "参数校验错误"),
    AUTH_VALID_ERROR(701, "用户权限不足"),
    UNLOGIN_ERROR(401, "用户未登录或登录状态超时失效"),
    ;

    private final Integer value;
    private final String message;

    ErrorCode(int value, String message) {
        this.value = value;
        this.message = message;
    }

    public int getValue() {
        return value;
    }

    public String getMessage() {
        return message;
    }

    @Override
    public String toString() {
        return value.toString();
    }

    public String getCode() {
        return value.toString();
    }

    public static ErrorCode getByCode(Integer value) {
        for (ErrorCode _enum : values()) {
            if (_enum.getValue() == value) {
                return _enum;
            }
        }
        return null;
    }

}

5. HttpStatus 提取自org.springframework.http,可以自己引入

/**
 * Enumeration of HTTP status codes.
 *
 * <p>The HTTP status code series can be retrieved via {@link #series()}.
 *
 * @author Arjen Poutsma
 * @author Sebastien Deleuze
 * @author Brian Clozel
 * @since 3.0
 * @see HttpStatus.Series
 * @see <a href="http://www.iana.org/assignments/http-status-codes">HTTP Status Code Registry</a>
 * @see <a href="http://en.wikipedia.org/wiki/List_of_HTTP_status_codes">List of HTTP status codes - Wikipedia</a>
 */
public enum HttpStatus {

	// 1xx Informational

	/**
	 * {@code 100 Continue}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.2.1">HTTP/1.1: Semantics and Content, section 6.2.1</a>
	 */
	CONTINUE(100, "Continue"),
	/**
	 * {@code 101 Switching Protocols}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.2.2">HTTP/1.1: Semantics and Content, section 6.2.2</a>
	 */
	SWITCHING_PROTOCOLS(101, "Switching Protocols"),
	/**
	 * {@code 102 Processing}.
	 * @see <a href="http://tools.ietf.org/html/rfc2518#section-10.1">WebDAV</a>
	 */
	PROCESSING(102, "Processing"),
	/**
	 * {@code 103 Checkpoint}.
	 * @see <a href="http://code.google.com/p/gears/wiki/ResumableHttpRequestsProposal">A proposal for supporting
	 * resumable POST/PUT HTTP requests in HTTP/1.0</a>
	 */
	CHECKPOINT(103, "Checkpoint"),

	// 2xx Success

	/**
	 * {@code 200 OK}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.3.1">HTTP/1.1: Semantics and Content, section 6.3.1</a>
	 */
	OK(200, "OK"),
	/**
	 * {@code 201 Created}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.3.2">HTTP/1.1: Semantics and Content, section 6.3.2</a>
	 */
	CREATED(201, "Created"),
	/**
	 * {@code 202 Accepted}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.3.3">HTTP/1.1: Semantics and Content, section 6.3.3</a>
	 */
	ACCEPTED(202, "Accepted"),
	/**
	 * {@code 203 Non-Authoritative Information}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.3.4">HTTP/1.1: Semantics and Content, section 6.3.4</a>
	 */
	NON_AUTHORITATIVE_INFORMATION(203, "Non-Authoritative Information"),
	/**
	 * {@code 204 No Content}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.3.5">HTTP/1.1: Semantics and Content, section 6.3.5</a>
	 */
	NO_CONTENT(204, "No Content"),
	/**
	 * {@code 205 Reset Content}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.3.6">HTTP/1.1: Semantics and Content, section 6.3.6</a>
	 */
	RESET_CONTENT(205, "Reset Content"),
	/**
	 * {@code 206 Partial Content}.
	 * @see <a href="http://tools.ietf.org/html/rfc7233#section-4.1">HTTP/1.1: Range Requests, section 4.1</a>
	 */
	PARTIAL_CONTENT(206, "Partial Content"),
	/**
	 * {@code 207 Multi-Status}.
	 * @see <a href="http://tools.ietf.org/html/rfc4918#section-13">WebDAV</a>
	 */
	MULTI_STATUS(207, "Multi-Status"),
	/**
	 * {@code 208 Already Reported}.
	 * @see <a href="http://tools.ietf.org/html/rfc5842#section-7.1">WebDAV Binding Extensions</a>
	 */
	ALREADY_REPORTED(208, "Already Reported"),
	/**
	 * {@code 226 IM Used}.
	 * @see <a href="http://tools.ietf.org/html/rfc3229#section-10.4.1">Delta encoding in HTTP</a>
	 */
	IM_USED(226, "IM Used"),

	// 3xx Redirection

	/**
	 * {@code 300 Multiple Choices}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.4.1">HTTP/1.1: Semantics and Content, section 6.4.1</a>
	 */
	MULTIPLE_CHOICES(300, "Multiple Choices"),
	/**
	 * {@code 301 Moved Permanently}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.4.2">HTTP/1.1: Semantics and Content, section 6.4.2</a>
	 */
	MOVED_PERMANENTLY(301, "Moved Permanently"),
	/**
	 * {@code 302 Found}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.4.3">HTTP/1.1: Semantics and Content, section 6.4.3</a>
	 */
	FOUND(302, "Found"),
	/**
	 * {@code 302 Moved Temporarily}.
	 * @see <a href="http://tools.ietf.org/html/rfc1945#section-9.3">HTTP/1.0, section 9.3</a>
	 * @deprecated in favor of {@link #FOUND} which will be returned from {@code HttpStatus.valueOf(302)}
	 */
	@Deprecated
	MOVED_TEMPORARILY(302, "Moved Temporarily"),
	/**
	 * {@code 303 See Other}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.4.4">HTTP/1.1: Semantics and Content, section 6.4.4</a>
	 */
	SEE_OTHER(303, "See Other"),
	/**
	 * {@code 304 Not Modified}.
	 * @see <a href="http://tools.ietf.org/html/rfc7232#section-4.1">HTTP/1.1: Conditional Requests, section 4.1</a>
	 */
	NOT_MODIFIED(304, "Not Modified"),
	/**
	 * {@code 305 Use Proxy}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.4.5">HTTP/1.1: Semantics and Content, section 6.4.5</a>
	 * @deprecated due to security concerns regarding in-band configuration of a proxy
	 */
	@Deprecated
	USE_PROXY(305, "Use Proxy"),
	/**
	 * {@code 307 Temporary Redirect}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.4.7">HTTP/1.1: Semantics and Content, section 6.4.7</a>
	 */
	TEMPORARY_REDIRECT(307, "Temporary Redirect"),
	/**
	 * {@code 308 Permanent Redirect}.
	 * @see <a href="http://tools.ietf.org/html/rfc7238">RFC 7238</a>
	 */
	PERMANENT_REDIRECT(308, "Permanent Redirect"),

	// --- 4xx Client Error ---

	/**
	 * {@code 400 Bad Request}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.1">HTTP/1.1: Semantics and Content, section 6.5.1</a>
	 */
	BAD_REQUEST(400, "Bad Request"),
	/**
	 * {@code 401 Unauthorized}.
	 * @see <a href="http://tools.ietf.org/html/rfc7235#section-3.1">HTTP/1.1: Authentication, section 3.1</a>
	 */
	UNAUTHORIZED(401, "Unauthorized"),
	/**
	 * {@code 402 Payment Required}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.2">HTTP/1.1: Semantics and Content, section 6.5.2</a>
	 */
	PAYMENT_REQUIRED(402, "Payment Required"),
	/**
	 * {@code 403 Forbidden}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.3">HTTP/1.1: Semantics and Content, section 6.5.3</a>
	 */
	FORBIDDEN(403, "Forbidden"),
	/**
	 * {@code 404 Not Found}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.4">HTTP/1.1: Semantics and Content, section 6.5.4</a>
	 */
	NOT_FOUND(404, "Not Found"),
	/**
	 * {@code 405 Method Not Allowed}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.5">HTTP/1.1: Semantics and Content, section 6.5.5</a>
	 */
	METHOD_NOT_ALLOWED(405, "Method Not Allowed"),
	/**
	 * {@code 406 Not Acceptable}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.6">HTTP/1.1: Semantics and Content, section 6.5.6</a>
	 */
	NOT_ACCEPTABLE(406, "Not Acceptable"),
	/**
	 * {@code 407 Proxy Authentication Required}.
	 * @see <a href="http://tools.ietf.org/html/rfc7235#section-3.2">HTTP/1.1: Authentication, section 3.2</a>
	 */
	PROXY_AUTHENTICATION_REQUIRED(407, "Proxy Authentication Required"),
	/**
	 * {@code 408 Request Timeout}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.7">HTTP/1.1: Semantics and Content, section 6.5.7</a>
	 */
	REQUEST_TIMEOUT(408, "Request Timeout"),
	/**
	 * {@code 409 Conflict}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.8">HTTP/1.1: Semantics and Content, section 6.5.8</a>
	 */
	CONFLICT(409, "Conflict"),
	/**
	 * {@code 410 Gone}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.9">HTTP/1.1: Semantics and Content, section 6.5.9</a>
	 */
	GONE(410, "Gone"),
	/**
	 * {@code 411 Length Required}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.10">HTTP/1.1: Semantics and Content, section 6.5.10</a>
	 */
	LENGTH_REQUIRED(411, "Length Required"),
	/**
	 * {@code 412 Precondition failed}.
	 * @see <a href="http://tools.ietf.org/html/rfc7232#section-4.2">HTTP/1.1: Conditional Requests, section 4.2</a>
	 */
	PRECONDITION_FAILED(412, "Precondition Failed"),
	/**
	 * {@code 413 Payload Too Large}.
	 * @since 4.1
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.11">HTTP/1.1: Semantics and Content, section 6.5.11</a>
	 */
	PAYLOAD_TOO_LARGE(413, "Payload Too Large"),
	/**
	 * {@code 413 Request Entity Too Large}.
	 * @see <a href="http://tools.ietf.org/html/rfc2616#section-10.4.14">HTTP/1.1, section 10.4.14</a>
	 * @deprecated in favor of {@link #PAYLOAD_TOO_LARGE} which will be returned from {@code HttpStatus.valueOf(413)}
	 */
	@Deprecated
	REQUEST_ENTITY_TOO_LARGE(413, "Request Entity Too Large"),
	/**
	 * {@code 414 URI Too Long}.
	 * @since 4.1
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.12">HTTP/1.1: Semantics and Content, section 6.5.12</a>
	 */
	URI_TOO_LONG(414, "URI Too Long"),
	/**
	 * {@code 414 Request-URI Too Long}.
	 * @see <a href="http://tools.ietf.org/html/rfc2616#section-10.4.15">HTTP/1.1, section 10.4.15</a>
	 * @deprecated in favor of {@link #URI_TOO_LONG} which will be returned from {@code HttpStatus.valueOf(414)}
	 */
	@Deprecated
	REQUEST_URI_TOO_LONG(414, "Request-URI Too Long"),
	/**
	 * {@code 415 Unsupported Media Type}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.13">HTTP/1.1: Semantics and Content, section 6.5.13</a>
	 */
	UNSUPPORTED_MEDIA_TYPE(415, "Unsupported Media Type"),
	/**
	 * {@code 416 Requested Range Not Satisfiable}.
	 * @see <a href="http://tools.ietf.org/html/rfc7233#section-4.4">HTTP/1.1: Range Requests, section 4.4</a>
	 */
	REQUESTED_RANGE_NOT_SATISFIABLE(416, "Requested range not satisfiable"),
	/**
	 * {@code 417 Expectation Failed}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.5.14">HTTP/1.1: Semantics and Content, section 6.5.14</a>
	 */
	EXPECTATION_FAILED(417, "Expectation Failed"),
	/**
	 * {@code 418 I'm a teapot}.
	 * @see <a href="http://tools.ietf.org/html/rfc2324#section-2.3.2">HTCPCP/1.0</a>
	 */
	I_AM_A_TEAPOT(418, "I'm a teapot"),
	/**
	 * @deprecated See <a href="http://tools.ietf.org/rfcdiff?difftype=--hwdiff&url2=draft-ietf-webdav-protocol-06.txt">WebDAV Draft Changes</a>
	 */
	@Deprecated
	INSUFFICIENT_SPACE_ON_RESOURCE(419, "Insufficient Space On Resource"),
	/**
	 * @deprecated See <a href="http://tools.ietf.org/rfcdiff?difftype=--hwdiff&url2=draft-ietf-webdav-protocol-06.txt">WebDAV Draft Changes</a>
	 */
	@Deprecated
	METHOD_FAILURE(420, "Method Failure"),
	/**
	 * @deprecated See <a href="http://tools.ietf.org/rfcdiff?difftype=--hwdiff&url2=draft-ietf-webdav-protocol-06.txt">WebDAV Draft Changes</a>
	 */
	@Deprecated
	DESTINATION_LOCKED(421, "Destination Locked"),
	/**
	 * {@code 422 Unprocessable Entity}.
	 * @see <a href="http://tools.ietf.org/html/rfc4918#section-11.2">WebDAV</a>
	 */
	UNPROCESSABLE_ENTITY(422, "Unprocessable Entity"),
	/**
	 * {@code 423 Locked}.
	 * @see <a href="http://tools.ietf.org/html/rfc4918#section-11.3">WebDAV</a>
	 */
	LOCKED(423, "Locked"),
	/**
	 * {@code 424 Failed Dependency}.
	 * @see <a href="http://tools.ietf.org/html/rfc4918#section-11.4">WebDAV</a>
	 */
	FAILED_DEPENDENCY(424, "Failed Dependency"),
	/**
	 * {@code 426 Upgrade Required}.
	 * @see <a href="http://tools.ietf.org/html/rfc2817#section-6">Upgrading to TLS Within HTTP/1.1</a>
	 */
	UPGRADE_REQUIRED(426, "Upgrade Required"),
	/**
	 * {@code 428 Precondition Required}.
	 * @see <a href="http://tools.ietf.org/html/rfc6585#section-3">Additional HTTP Status Codes</a>
	 */
	PRECONDITION_REQUIRED(428, "Precondition Required"),
	/**
	 * {@code 429 Too Many Requests}.
	 * @see <a href="http://tools.ietf.org/html/rfc6585#section-4">Additional HTTP Status Codes</a>
	 */
	TOO_MANY_REQUESTS(429, "Too Many Requests"),
	/**
	 * {@code 431 Request Header Fields Too Large}.
	 * @see <a href="http://tools.ietf.org/html/rfc6585#section-5">Additional HTTP Status Codes</a>
	 */
	REQUEST_HEADER_FIELDS_TOO_LARGE(431, "Request Header Fields Too Large"),
	/**
	 * {@code 451 Unavailable For Legal Reasons}.
	 * @see <a href="https://tools.ietf.org/html/draft-ietf-httpbis-legally-restricted-status-04">
	 * An HTTP Status Code to Report Legal Obstacles</a>
	 * @since 4.3
	 */
	UNAVAILABLE_FOR_LEGAL_REASONS(451, "Unavailable For Legal Reasons"),

	// --- 5xx Server Error ---

	/**
	 * {@code 500 Internal Server Error}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.6.1">HTTP/1.1: Semantics and Content, section 6.6.1</a>
	 */
	INTERNAL_SERVER_ERROR(500, "Internal Server Error"),
	/**
	 * {@code 501 Not Implemented}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.6.2">HTTP/1.1: Semantics and Content, section 6.6.2</a>
	 */
	NOT_IMPLEMENTED(501, "Not Implemented"),
	/**
	 * {@code 502 Bad Gateway}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.6.3">HTTP/1.1: Semantics and Content, section 6.6.3</a>
	 */
	BAD_GATEWAY(502, "Bad Gateway"),
	/**
	 * {@code 503 Service Unavailable}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.6.4">HTTP/1.1: Semantics and Content, section 6.6.4</a>
	 */
	SERVICE_UNAVAILABLE(503, "Service Unavailable"),
	/**
	 * {@code 504 Gateway Timeout}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.6.5">HTTP/1.1: Semantics and Content, section 6.6.5</a>
	 */
	GATEWAY_TIMEOUT(504, "Gateway Timeout"),
	/**
	 * {@code 505 HTTP Version Not Supported}.
	 * @see <a href="http://tools.ietf.org/html/rfc7231#section-6.6.6">HTTP/1.1: Semantics and Content, section 6.6.6</a>
	 */
	HTTP_VERSION_NOT_SUPPORTED(505, "HTTP Version not supported"),
	/**
	 * {@code 506 Variant Also Negotiates}
	 * @see <a href="http://tools.ietf.org/html/rfc2295#section-8.1">Transparent Content Negotiation</a>
	 */
	VARIANT_ALSO_NEGOTIATES(506, "Variant Also Negotiates"),
	/**
	 * {@code 507 Insufficient Storage}
	 * @see <a href="http://tools.ietf.org/html/rfc4918#section-11.5">WebDAV</a>
	 */
	INSUFFICIENT_STORAGE(507, "Insufficient Storage"),
	/**
	 * {@code 508 Loop Detected}
	 * @see <a href="http://tools.ietf.org/html/rfc5842#section-7.2">WebDAV Binding Extensions</a>
 	 */
	LOOP_DETECTED(508, "Loop Detected"),
	/**
	 * {@code 509 Bandwidth Limit Exceeded}
 	 */
	BANDWIDTH_LIMIT_EXCEEDED(509, "Bandwidth Limit Exceeded"),
	/**
	 * {@code 510 Not Extended}
	 * @see <a href="http://tools.ietf.org/html/rfc2774#section-7">HTTP Extension Framework</a>
	 */
	NOT_EXTENDED(510, "Not Extended"),
	/**
	 * {@code 511 Network Authentication Required}.
	 * @see <a href="http://tools.ietf.org/html/rfc6585#section-6">Additional HTTP Status Codes</a>
	 */
	NETWORK_AUTHENTICATION_REQUIRED(511, "Network Authentication Required");


	private final int value;

	private final String reasonPhrase;


	HttpStatus(int value, String reasonPhrase) {
		this.value = value;
		this.reasonPhrase = reasonPhrase;
	}


	/**
	 * Return the integer value of this status code.
	 */
	public int value() {
		return this.value;
	}

	/**
	 * Return the reason phrase of this status code.
	 */
	public String getReasonPhrase() {
		return this.reasonPhrase;
	}

	/**
	 * Whether this status code is in the HTTP series
	 * {@link org.springframework.http.HttpStatus.Series#INFORMATIONAL}.
	 * This is a shortcut for checking the value of {@link #series()}.
	 */
	public boolean is1xxInformational() {
		return Series.INFORMATIONAL.equals(series());
	}

	/**
	 * Whether this status code is in the HTTP series
	 * {@link org.springframework.http.HttpStatus.Series#SUCCESSFUL}.
	 * This is a shortcut for checking the value of {@link #series()}.
	 */
	public boolean is2xxSuccessful() {
		return Series.SUCCESSFUL.equals(series());
	}

	/**
	 * Whether this status code is in the HTTP series
	 * {@link org.springframework.http.HttpStatus.Series#REDIRECTION}.
	 * This is a shortcut for checking the value of {@link #series()}.
	 */
	public boolean is3xxRedirection() {
		return Series.REDIRECTION.equals(series());
	}


	/**
	 * Whether this status code is in the HTTP series
	 * {@link org.springframework.http.HttpStatus.Series#CLIENT_ERROR}.
	 * This is a shortcut for checking the value of {@link #series()}.
	 */
	public boolean is4xxClientError() {
		return Series.CLIENT_ERROR.equals(series());
	}

	/**
	 * Whether this status code is in the HTTP series
	 * {@link org.springframework.http.HttpStatus.Series#SERVER_ERROR}.
	 * This is a shortcut for checking the value of {@link #series()}.
	 */
	public boolean is5xxServerError() {
		return Series.SERVER_ERROR.equals(series());
	}

	/**
	 * Returns the HTTP status series of this status code.
	 * @see HttpStatus.Series
	 */
	public Series series() {
		return Series.valueOf(this);
	}

	/**
	 * Return a string representation of this status code.
	 */
	@Override
	public String toString() {
		return Integer.toString(this.value);
	}


	/**
	 * Return the enum constant of this type with the specified numeric value.
	 * @param statusCode the numeric value of the enum to be returned
	 * @return the enum constant with the specified numeric value
	 * @throws IllegalArgumentException if this enum has no constant for the specified numeric value
	 */
	public static HttpStatus valueOf(int statusCode) {
		for (HttpStatus status : values()) {
			if (status.value == statusCode) {
				return status;
			}
		}
		throw new IllegalArgumentException("No matching constant for [" + statusCode + "]");
	}


	/**
	 * Enumeration of HTTP status series.
	 * <p>Retrievable via {@link HttpStatus#series()}.
	 */
	public enum Series {

		INFORMATIONAL(1),
		SUCCESSFUL(2),
		REDIRECTION(3),
		CLIENT_ERROR(4),
		SERVER_ERROR(5);

		private final int value;

		Series(int value) {
			this.value = value;
		}

		/**
		 * Return the integer value of this status series. Ranges from 1 to 5.
		 */
		public int value() {
			return this.value;
		}

		public static Series valueOf(int status) {
			int seriesCode = status / 100;
			for (Series series : values()) {
				if (series.value == seriesCode) {
					return series;
				}
			}
			throw new IllegalArgumentException("No matching constant for [" + status + "]");
		}

		public static Series valueOf(HttpStatus status) {
			return valueOf(status.value);
		}
	}

}

6. 测试示例：


    @ResponseBody
    @RequestMapping("/json")
    public Resp json(String token) {
        MemberDetails member = memberService.getMemberDetailsByToken(token);
        return Resp.success(member, 5L, 1, 3); //这里分页信息，请自己从PageHelper返回的数据中得到。参看下面注释内容：

        //Page<Object> page = PageHelper.startPage(1, 5);
        //MemberDetails member = memberService.getMemberDetailsByToken(token);
        //return Resp.success(member, page.getTotal(), page.getPageNum(), page.getPageSize());
    }

    @ResponseBody
    @RequestMapping("/json2")
    public Resp json2(String token) {
        MemberDetails member = memberService.getMemberDetailsByToken(token);
        Map<String, Object> ext = new HashMap<>();
        ext.put("msg", "扩展内容");
        return Resp.success("成功了", member, ext, 5L, 1, 3);
    }

    @ResponseBody
    @RequestMapping("/json3")
    public Resp json3(String token) {
        MemberDetails member = memberService.getMemberDetailsByToken(token);
        return Resp.fail();
    }

    @ResponseBody
    @RequestMapping("/json4")
    public Resp json4(String token) {
        MemberDetails member = memberService.getMemberDetailsByToken(token);
        Map<String, Object> ext = new HashMap<>();
        ext.put("msg", "扩展内容");
        return Resp.result("201", "成功了", member);
    }

    @ResponseBody
    @RequestMapping("/json5")
    public Resp json5(String token) {
        MemberDetails member = memberService.getMemberDetailsByToken(token);
        return Resp.success(member);
    }

    @ResponseBody
    @RequestMapping("/json6")
    public Resp json6(String token) {
        MemberDetails member = memberService.getMemberDetailsByToken(token);
        return Resp.httpStatus(HttpStatus.ACCEPTED, "成功了");
    }

7. 运行结果：

访问：http://127.0.0.1:1230/json?token=123
访问：http://127.0.0.1:1230/json2?token=123
访问：http://127.0.0.1:1230/json3?token=123
访问：http://127.0.0.1:1230/json4?token=123
访问：http://127.0.0.1:1230/json5?token=123
访问：http://127.0.0.1:1230/json6?token=123

更多用法，请查看Resp类里面的静态方法

后记：

如果大家有更好的改进建议或代码，欢迎在评论留言反馈，谢谢！

原文地址：http://www.seifon.cn/2018/04/30/Spring统一返回Json工具类，带分页信息/