java模板模式项目中使用--封装一个http请求工具类

需要调用http接口的代码继承FundHttpTemplate类，重写getParamData方法，在getParamDate里写调用逻辑。

模板：

package com.crb.ocms.fund.domain.util.http;

import com.alibaba.fastjson.JSONArray;
import com.crb.ocms.fund.domain.util.HttpUtil;
import com.ibm.sc.osp.base.core.util.StringUtils;
import lombok.extern.slf4j.Slf4j;

import java.lang.reflect.ParameterizedType;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @Project crb-fund
 * @PackageName com.crb.ocms.product.service
 * @ClassName FundHttpTemplate
 * @Author kc
 * @Date 2019/4/4 10:50
 * @Description  走http的公共继承模板方法，第一个泛型为请求的参数类型，第二个参数为返回的参数类型
 */
@Slf4j
public abstract class FundHttpTemplate<T,K> {

    /**
     * 地址请求
     * @return 请求地址
     */
    protected abstract String linkHttp();

    /**
     * 得到响应数据
     * @param t
     * @return
     */
    public List<K> getData(T t) {

        Map<String, String> request_map = new HashMap<>(1);
        request_map.put("Content-Type", "application/json");
        String url = linkHttp();
        //封装请求参数
        String params = getParamsData(t);
        String dataObj = HttpUtil.sendPost(url, params, request_map);
        if (StringUtils.isNotEmpty(dataObj)) {
            try {
                Class <K> entityClass = (Class <K>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[1];
                List<K> ts = (List<K>) JSONArray.parseArray(dataObj, entityClass);
                return ts;
            } catch (Exception e) {
                e.printStackTrace();
                log.error("获取数据异常原始数据：{}",dataObj);
                return null;
            }
        } else {
            log.error("获取数据异常");
            return null;
        }
    }

    /**
     * 构造参数
     * @param t
     * @return
     */
    protected abstract String getParamsData(T t);

}

httpUtil:

package com.crb.ocms.fund.domain.util;

import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.Map;
/**
 * @Project crb-cost-domain
 * @PackageName com.crb.ocms.cost.cost.util
 * @ClassName HttpUtil
 * @Author kc
 * @Date 2019/2/21 13:39
 * @Description http请求工具类
 */
@Component
public class HttpUtil {
    private static PoolingHttpClientConnectionManager cm;
    private static String EMPTY_STR = "";
    private static String UTF_8 = "UTF-8";

    private static Integer maxTotal;

    private static Integer maxPerRoute;

    @Value("${httpconfig.maxTotal}")
    public void setMaxTota(Integer maxTotal) {
        HttpUtil.maxTotal = maxTotal;
    }
    @Value("${httpconfig.maxPerRoute}")
    public void setMaxPerRoute(Integer maxPerRoute) {
        HttpUtil.maxPerRoute = maxPerRoute;
    }

    private static void init() {
        if (cm == null) {
            cm = new PoolingHttpClientConnectionManager();
            // 整个连接池最大连接数
            cm.setMaxTotal(maxTotal);
            // 每路由最大连接数，默认值是2
            cm.setDefaultMaxPerRoute(maxPerRoute);
        }
    }

    /**
     * 通过连接池获取HttpClient
     *
     * @return
     */
    private static CloseableHttpClient getHttpClient() {
        init();
        return HttpClients.custom().setConnectionManager(cm).build();
    }

    /**
     * @param url
     * @return
     */
    public static String sendGet(String url) {
        HttpGet httpGet = new HttpGet(url);
        return getResult(httpGet);
    }

    /**
     * get请求 带参数
     * @param url
     * @param params
     * @return
     * @throws URISyntaxException
     */
    public static String sendGet(String url, Map<String, String> params) {
        URIBuilder ub = new URIBuilder();
        ub.setPath(url);
        ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
        ub.setParameters(pairs);
        HttpGet httpGet = null;
        try {
            httpGet = new HttpGet(ub.build());
        } catch (URISyntaxException e) {
            e.printStackTrace();
        }
        return getResult(httpGet);
    }

    /**
     * get请求 带参数带header
     * @param url
     * @param headers
     * @param params
     * @return
     * @throws URISyntaxException
     */
    public static String sendGet(String url, Map<String, String> headers, Map<String, String> params)
    {
        URIBuilder ub = new URIBuilder();
        ub.setPath(url);
        ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
        ub.setParameters(pairs);
        HttpGet httpGet = null;
        try {
            httpGet = new HttpGet(ub.build());
        } catch (URISyntaxException e) {
            e.printStackTrace();
        }
        for (Map.Entry<String, String> param : headers.entrySet()) {
            httpGet.addHeader(param.getKey(), String.valueOf(param.getValue()));
        }
        return getResult(httpGet);
    }

    /**
     * post基本请求
     * @param url
     * @return
     */
    public static String sendPost(String url) {
        HttpPost httpPost = new HttpPost(url);
        return getResult(httpPost);
    }

    /**
     * post请求 str参数
     * @param url
     * @param param
     * @return
     */
    public static String sendPost(String url,String param) {
        HttpPost httpPost = new HttpPost(url);
        //解决中文乱码问题
        StringEntity entity = new StringEntity(param,"utf-8");
        entity.setContentEncoding("UTF-8");
        entity.setContentType("application/json");
        httpPost.setEntity(entity);
        return getResult(httpPost);
    }

    /**
     * post请求 带参数
     * @param url
     * @param params
     * @return
     * @throws UnsupportedEncodingException
     */
    public static String sendPost(String url, Map<String, String> params)  {
        HttpPost httpPost = new HttpPost(url);
        ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
        try {
            httpPost.setEntity(new UrlEncodedFormEntity(pairs, UTF_8));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return getResult(httpPost);
    }
    /**
     * post请求 带参数
     * @param url
     * @param param
     * @param headers
     * @return
     * @throws UnsupportedEncodingException
     */
    public static String sendPost(String url,String param, Map<String, String> headers) {
        HttpPost httpPost = new HttpPost(url);
        //解决中文乱码问题
        StringEntity entity = new StringEntity(param,"utf-8");
        entity.setContentEncoding("UTF-8");
        entity.setContentType("application/json");
        httpPost.setEntity(entity);
        for (Map.Entry<String, String> head : headers.entrySet()) {
            httpPost.addHeader(head.getKey(), head.getValue());
        }
        return getResult(httpPost);
    }

    /**
     * post请求 带header 带参数
     * @param url
     * @param headers
     * @param params
     * @return
     * @throws UnsupportedEncodingException
     */
    public static String sendPost(String url, Map<String, String> headers, Map<String, String> params)
            throws UnsupportedEncodingException {
        HttpPost httpPost = new HttpPost(url);
        for (Map.Entry<String, String> param : headers.entrySet()) {
            httpPost.addHeader(param.getKey(), String.valueOf(param.getValue()));
        }
        ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
        httpPost.setEntity(new UrlEncodedFormEntity(pairs, UTF_8));

        return getResult(httpPost);
    }

    /**
     * 参数封装
     * @param params
     * @return
     */
    private static ArrayList<NameValuePair> covertParams2NVPS(Map<String, String> params) {
        ArrayList<NameValuePair> pairs = new ArrayList<NameValuePair>();
        for (Map.Entry<String, String> param : params.entrySet()) {
            pairs.add(new BasicNameValuePair(param.getKey(), param.getValue()));
        }
        return pairs;
    }

    /**
     * 处理Http请求结果
     * @param request
     * @return
     */
    private static String getResult(HttpRequestBase request) {
        CloseableHttpClient httpClient = getHttpClient();
        try {
            CloseableHttpResponse response = httpClient.execute(request);
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                String result = EntityUtils.toString(entity,"UTF-8");
                response.close();
                return result;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return EMPTY_STR;
    }

}

实现类：

package com.crb.ocms.fund.domain.util.http;

import com.alibaba.fastjson.JSONObject;
import com.crb.ocms.fund.domain.po.PackingDepositAccount;
import com.crb.ocms.fund.domain.util.http.FundHttpTemplate;
import com.crb.ocms.fund.domain.vo.req.IcPackingDepositAccountQueryVo;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

/**
 * @Project ocms
 * @PackageName com.crb.ocms.fund.api.config
 * @ClassName IcPackingAccountDepositForHttp
 * @Author
 * @Date 2019/4/8 0008 上午 11:08
 * @Description
 */
@Component
public class IcPackingAccountDepositForHttp extends FundHttpTemplate<IcPackingDepositAccountQueryVo,PackingDepositAccount> {

    @Value("${icPackingAccountDeposit.url}")
    private String icPackingAccountDepositUrl;

    @Override
    protected String linkHttp() {
        return icPackingAccountDepositUrl;
    }

    @Override
    protected String getParamsData(IcPackingDepositAccountQueryVo queryVo) {
        JSONObject param = new JSONObject();
        //param.put("regionCode",queryVo.getRegionCode());
        param.put("corporationId",queryVo.getCorporationId());
        param.put("customerId",queryVo.getCustomerId());
        return param.toJSONString();
    }
}

调用类：

        List<PackingDepositAccount> packingDepositAccounts = icPackingAccountDepositForHttp.getData(depositAccountQueryVo);
        if(log.isDebugEnabled()){
            log.debug("通过HTTP查询前端视图数据--代保管账户余额》》》》》》》{}",JSONObject.toJSONString(packingDepositAccounts));
        }