第三方接口调用：BasicNameValuePair封装post请求中的参数名称和值

第三方接口调用时，根据接口文档封装请求类和接收类，定义一个公用方法发送post请求。

• baseReq类：

package com.wy.interfacecall.apiReq;

import lombok.Data;

import java.io.Serializable;

/**
 * base请求类
 *
 * @author wangyan@163.com
 * @version 1.0
 * @date 2019-12-30 09:56
 */
@Data
public class BaseReq implements Serializable {

    // 公用请求字段
    private String id;
    private String uCode;
    private String sign;
    private Long timeStamp;

    public String getReqPath() {
        return null;
    }
}

• baseResp类：

package com.wy.interfacecall.apiReq;

import lombok.Data;

import java.io.Serializable;

/**
 * base响应类
 *
 * @author wangyan@163.com
 * @version 1.0
 * @date 2019-12-30 10:01
 */
@Data
public class BaseResp implements Serializable {
    // 响应码
    private Integer code;
    // 响应信息
    private String msg;
}

• 请求类：

package com.wy.interfacecall.apiReq;

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

/**
 * 获取商品请求封装类
 *
 * @author wangyan@163.com
 * @version 1.0
 * @date 2019-12-30 10:03
 */
@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class GetProductReq extends BaseReq {

    public static final String REQ_URL = "xxxxxx";

    // 页数
    private Integer page;

    // 每页记录数
    private Integer rows;

    // 创建时间
    private String createTime;

    @Override
    public String getReqPath() {
        return GetProductReq.REQ_URL;
    }

// 印象中，无参构造上方加 @Tolerate注解可以解决 @Builder和 @Data共用时没有无参方法的问题
//    @Tolerate
//    public GetProductReq() {
//    }

}

• 响应类：

package com.wy.interfacecall.apiReq;

import com.alibaba.fastjson.annotation.JSONField;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;
import java.util.List;

/**
 * 获取商品响应类
 *
 * @author wangyan@163.com
 * @version 1.0
 * @date 2019-12-30 10:10
 */
@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class GetProductResp extends BaseResp {
    // 对应第三方接口返回的数据形式
    @JSONField(name = "data")
    private List<Product> productList;

    @Data
    public static class Product implements Serializable {
        private String productId;
        private String productName;
        private Double productPrice;
    }
}

• 接口定义：

package com.wy.interfacecall.service;

import com.wy.interfacecall.apiReq.BaseReq;
import com.wy.interfacecall.apiReq.BaseResp;
import com.wy.interfacecall.apiReq.GetProductResp;

/**
 * @author wangyan@163.com
 * @version 1.0
 * @date 2019-12-30 10:19
 */
public interface ApiService {
    // api公用请求接口
    BaseResp legacyApiInvoker(BaseReq baseReq, BaseResp baseResp);

    // 获取商品接口(传入请求参数，实现类中build请求对象)
    GetProductResp getProduct(Integer page, Integer rows, String createTime);
}

• 实现类：

package com.wy.interfacecall.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.date.DateUtil;
import cn.hutool.core.util.URLUtil;
import cn.hutool.crypto.digest.DigestUtil;
import cn.hutool.http.HttpUtil;
import com.alibaba.fastjson.JSON;
import com.wy.interfacecall.apiConfig.ApiConfig;
import com.wy.interfacecall.apiReq.BaseReq;
import com.wy.interfacecall.apiReq.BaseResp;
import com.wy.interfacecall.apiReq.GetProductReq;
import com.wy.interfacecall.apiReq.GetProductResp;
import com.wy.interfacecall.service.ApiService;
import lombok.extern.slf4j.Slf4j;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.message.BasicNameValuePair;
import org.springframework.beans.factory.annotation.Autowired;

import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import java.util.stream.Collectors;

/**
 * 实现类
 *
 * @author wangyan@163.com
 * @version 1.0
 * @date 2019-12-30 10:22
 */
@Slf4j
public class ApiServiceImpl implements ApiService {
    @Autowired
    private ApiConfig apiConfig;

    @Override
    public BaseResp legacyApiInvoker(BaseReq req, BaseResp resp) {
        req.setId(apiConfig.getId());
        req.setUCode(apiConfig.getUCode());
        req.setTimeStamp(DateUtil.currentSeconds());

        Map<String, Object> paramMap = new TreeMap<>();
        // 请求对象转为map
        paramMap = BeanUtil.beanToMap(req, paramMap, false, true);

        // BasicNameValuePair通常是用来封装post请求中的参数名称和值,且name和value必须为String类型
        List<BasicNameValuePair> params = paramMap.entrySet().stream().map(item -> new BasicNameValuePair(item.getKey(), item.getValue().toString())).collect(Collectors.toList());

        // MD5加密后转大写
        String signStr = DigestUtil.md5Hex(URLUtil.decode(URLEncodedUtils.format(params, "utf-8"))).toUpperCase();
        paramMap.put("sign", signStr);

        log.info("请求路径:{},请求参数:{}", req.getReqPath(), paramMap);

        // 发送请求
        String result = HttpUtil.post(apiConfig.getBaseAPIURL() + req.getReqPath(), paramMap);
        log.info("响应结果:{}", result);
        return JSON.parseObject(result, resp.getClass());
    }

    @Override
    public GetProductResp getProduct(Integer page, Integer rows, String createTime) {

        // build出一个请求对象
        GetProductReq req = GetProductReq.builder().page(page).rows(rows).createTime(createTime).build();

        // 调用方法发送请求
        return (GetProductResp) legacyApiInvoker(req, new GetProductResp());
    }
}

• 配置类：

package com.wy.interfacecall.apiConfig;

import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

/**
 * 配置类
 *
 * @author wangyan@163.com
 * @version 1.0
 * @date 2019-12-30 10:23
 */
@Data
@Component
@ConfigurationProperties(prefix = "xxx.api")// 对应yml或者properties文件中配置
public class ApiConfig {
    // 请求域名
    private String baseAPIURL;
    /**
     * 商户ID
     */
    private String id;

    /**
     * 接入码
     */
    private String uCode;

    private String appKey;

    private String secret;
}

• yml配置形式：

xxx:
  api:
    baseAPIURL: ${API_URL:http://xxxxxxx}
    id: ${API_ID:xxx}
    uCode: ${API_UCODE:xxx}