springcloud（二）微服务接口规范

微服务接口规范是指controller层的规范
controller的功能应该有以下五点：
1.参数校验
2.调用service层接口实现业务逻辑
3.转换业务／数据对象
4.组装返回对象
5.异常处理

1. 定义状态码枚举类StatusEnum.java

package com.wd.cloud.commons.enums;

import org.springframework.lang.Nullable;

/**
 * @author He Zhigang
 * @date 2018/10/10
 * @Description:
 */
public enum StatusEnum {
    /**
     * 未知异常
     */
    UNKNOWN(-1, "unknow exception"),
    /**
     * 成功
     */
    SUCCESS(1, "successed"),
    /**
     * 失败
     */
    FAIL(0, "failed"),
    /**
     * HTTP状态码
     */
    CONTINUE(100, "Continue"),
    SWITCHING_PROTOCOLS(101, "Switching Protocols"),
    PROCESSING(102, "Processing"),
    CHECKPOINT(103, "Checkpoint"),
    OK(200, "OK"),
    CREATED(201, "Created"),
    ACCEPTED(202, "Accepted"),
    NON_AUTHORITATIVE_INFORMATION(203, "Non-Authoritative Information"),
    NO_CONTENT(204, "No Content"),
    RESET_CONTENT(205, "Reset Content"),
    PARTIAL_CONTENT(206, "Partial Content"),
    MULTI_STATUS(207, "Multi-Status"),
    ALREADY_REPORTED(208, "Already Reported"),
    IM_USED(226, "IM Used"),
    MULTIPLE_CHOICES(300, "Multiple Choices"),
    MOVED_PERMANENTLY(301, "Moved Permanently"),
    FOUND(302, "Found"),
    /**
     * @deprecated
     */
    @Deprecated
    MOVED_TEMPORARILY(302, "Moved Temporarily"),
    SEE_OTHER(303, "See Other"),
    NOT_MODIFIED(304, "Not Modified"),
    /**
     * @deprecated
     */
    @Deprecated
    USE_PROXY(305, "Use Proxy"),
    TEMPORARY_REDIRECT(307, "Temporary Redirect"),
    PERMANENT_REDIRECT(308, "Permanent Redirect"),
    BAD_REQUEST(400, "Bad Request"),
    UNAUTHORIZED(401, "Unauthorized"),
    PAYMENT_REQUIRED(402, "Payment Required"),
    FORBIDDEN(403, "Forbidden"),
    NOT_FOUND(404, "Not Found"),
    METHOD_NOT_ALLOWED(405, "Method Not Allowed"),
    NOT_ACCEPTABLE(406, "Not Acceptable"),
    PROXY_AUTHENTICATION_REQUIRED(407, "Proxy Authentication Required"),
    REQUEST_TIMEOUT(408, "Request Timeout"),
    CONFLICT(409, "Conflict"),
    GONE(410, "Gone"),
    LENGTH_REQUIRED(411, "Length Required"),
    PRECONDITION_FAILED(412, "Precondition Failed"),
    PAYLOAD_TOO_LARGE(413, "Payload Too Large"),
    /**
     * @deprecated
     */
    @Deprecated
    REQUEST_ENTITY_TOO_LARGE(413, "Request Entity Too Large"),
    URI_TOO_LONG(414, "URI Too Long"),
    /**
     * @deprecated
     */
    @Deprecated
    REQUEST_URI_TOO_LONG(414, "Request-URI Too Long"),
    UNSUPPORTED_MEDIA_TYPE(415, "Unsupported Media Type"),
    REQUESTED_RANGE_NOT_SATISFIABLE(416, "Requested range not satisfiable"),
    EXPECTATION_FAILED(417, "Expectation Failed"),
    I_AM_A_TEAPOT(418, "I'm a teapot"),
    /**
     * @deprecated
     */
    @Deprecated
    INSUFFICIENT_SPACE_ON_RESOURCE(419, "Insufficient Space On Resource"),
    /**
     * @deprecated
     */
    @Deprecated
    METHOD_FAILURE(420, "Method Failure"),
    /**
     * @deprecated
     */
    @Deprecated
    DESTINATION_LOCKED(421, "Destination Locked"),
    UNPROCESSABLE_ENTITY(422, "Unprocessable Entity"),
    LOCKED(423, "Locked"),
    FAILED_DEPENDENCY(424, "Failed Dependency"),
    UPGRADE_REQUIRED(426, "Upgrade Required"),
    PRECONDITION_REQUIRED(428, "Precondition Required"),
    TOO_MANY_REQUESTS(429, "Too Many Requests"),
    REQUEST_HEADER_FIELDS_TOO_LARGE(431, "Request Header Fields Too Large"),
    UNAVAILABLE_FOR_LEGAL_REASONS(451, "Unavailable For Legal Reasons"),
    INTERNAL_SERVER_ERROR(500, "Internal Server Error"),
    NOT_IMPLEMENTED(501, "Not Implemented"),
    BAD_GATEWAY(502, "Bad Gateway"),
    SERVICE_UNAVAILABLE(503, "Service Unavailable"),
    GATEWAY_TIMEOUT(504, "Gateway Timeout"),
    HTTP_VERSION_NOT_SUPPORTED(505, "HTTP Version not supported"),
    VARIANT_ALSO_NEGOTIATES(506, "Variant Also Negotiates"),
    INSUFFICIENT_STORAGE(507, "Insufficient Storage"),
    LOOP_DETECTED(508, "Loop Detected"),
    BANDWIDTH_LIMIT_EXCEEDED(509, "Bandwidth Limit Exceeded"),
    NOT_EXTENDED(510, "Not Extended"),
    NETWORK_AUTHENTICATION_REQUIRED(511, "Network Authentication Required"),
    /**
     * 数据库异常状态码
     */
    DB_EXCEPTION(1001, "数据库异常"),
    DB_PRIMARY_EXCEPTION(1002, "主键冲突"),
   
    private final int value;
    private final String message;

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

    public static StatusEnum valueOf(int statusCode) {
        StatusEnum status = resolve(statusCode);
        if (status == null) {
            throw new IllegalArgumentException("No matching constant for [" + statusCode + "]");
        } else {
            return status;
        }
    }

    @Nullable
    public static StatusEnum resolve(int statusCode) {
        StatusEnum[] statusEnums = values();
        for (StatusEnum statusEnum : statusEnums) {
            if (statusEnum.value == statusCode) {
                return statusEnum;
            }
        }
        return null;
    }

    public int value() {
        return value;
    }

    public String getMessage() {
        return message;
    }

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

2. 定义API统一返回对象ResponseModel.java

package com.wd.cloud.commons.model;

import com.wd.cloud.commons.enums.StatusEnum;

import java.io.Serializable;

/**
 * @author He Zhigang
 * @date 2018/5/3
 * @remark api返回的response对象
 */
public class ResponseModel<T> implements Serializable {
    /**
     * 是否失败？error==true？失败：成功；
     */
    private boolean error;
    private Integer status;
    private String message;
    private T body;

    public ResponseModel(){}

    private ResponseModel(Throwable e) {
        this.error = true;
        this.message = e.toString();
        this.status = StatusEnum.FAIL.value();
    }

    private ResponseModel(StatusEnum statusEnum, boolean error) {
        this.error = error;
        this.status = statusEnum.value();
        this.message = statusEnum.getMessage();
    }

    public static ResponseModel ok() {
        return new ResponseModel(StatusEnum.SUCCESS, false);
    }

    public static ResponseModel ok(StatusEnum statusEnum) {
        return new ResponseModel(statusEnum, false);
    }

    /**
     * 请求失败，默认StatusEnum.FAIL
     *
     * @return
     */
    public static ResponseModel fail() {
        return new ResponseModel(StatusEnum.FAIL, true);
    }

    /**
     * 请求失败
     *
     * @param statusEnum
     * @return
     */
    public static ResponseModel fail(StatusEnum statusEnum) {
        return new ResponseModel(statusEnum, true);
    }

    public static ResponseModel fail(Throwable e) {
        return new ResponseModel(e);
    }

    public static ResponseModel serverError() {
        return new ResponseModel(StatusEnum.INTERNAL_SERVER_ERROR, true);
    }

    public Integer status() {
        return status;
    }

    public ResponseModel<T> status(Integer status) {
        this.status = status;
        return this;
    }

    public String message() {
        return message;
    }

    public ResponseModel<T> message(String message) {
        this.message = message;
        return this;
    }

    public T body() {
        return body;
    }

    public ResponseModel<T> body(T body) {
        this.body = body;
        return this;
    }

    public boolean isError() {
        return error;
    }

    public ResponseModel<T> setError(boolean error) {
        this.error = error;
        return this;
    }
}