Java访问外部接口工具类

使用场景：本地Java工程需要访问外部接口获取数据。

第一步：添加mven依赖

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.10</version>
</dependency>

第二步：编写工具类

package com.gocom.buintelligence.utils;

import java.io.IOException;
import java.net.URI;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

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.utils.URIBuilder;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

public class HttpClientUtil {

    public static String doGet(String url, Map<String, String> param) {

        // 创建Httpclient对象
        CloseableHttpClient httpclient = HttpClients.createDefault();

        String resultString = "";
        CloseableHttpResponse response = null;
        try {
            // 创建uri
            URIBuilder builder = new URIBuilder(url);
            if (param != null) {
                for (String key : param.keySet()) {
                    builder.addParameter(key, param.get(key));
                }
            }
            URI uri = builder.build();

            // 创建http GET请求
            HttpGet httpGet = new HttpGet(uri);

            // 执行请求
            response = httpclient.execute(httpGet);
            // 判断返回状态是否为200
            if (response.getStatusLine().getStatusCode() == 200) {
                resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (response != null) {
                    response.close();
                }
                httpclient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return resultString;
    }

    public static String doGet(String url) {
        return doGet(url, null);
    }

    public static String doPost(String url, Map<String, String> param) {
        // 创建Httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        String resultString = "";
        try {
            // 创建Http Post请求
            HttpPost httpPost = new HttpPost(url);
            // 创建参数列表
            if (param != null) {
                List<NameValuePair> paramList = new ArrayList<>();
                for (String key : param.keySet()) {
                    paramList.add(new BasicNameValuePair(key, param.get(key)));
                }
                // 模拟表单
                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList);
                httpPost.setEntity(entity);
            }
            // 执行http请求
            response = httpClient.execute(httpPost);
            resultString = EntityUtils.toString(response.getEntity(), "utf-8");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                response.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        return resultString;
    }

    public static String doPost(String url) {
        return doPost(url, null);
    }

    public static String doPostJson(String url, String json) {
        // 创建Httpclient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpResponse response = null;
        String resultString = "";
        try {
            // 创建Http Post请求
            HttpPost httpPost = new HttpPost(url);
            // 创建请求内容
            StringEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON);
            httpPost.setEntity(entity);
            // 执行http请求
            response = httpClient.execute(httpPost);
            resultString = EntityUtils.toString(response.getEntity(), "utf-8");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                response.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        return resultString;
    }
}

 

支持Https接口请求(httpClient创建时进行区别即可)

/**
 * POST请求区分是https 和 http
 * @param url
 * @param json
 * @param isSsl true https请求 false http请求
 * @return
 */
public static String doPostJson(String url, String json, boolean isSsl) {
    CloseableHttpClient httpClient;
    CloseableHttpResponse response = null;
    String resultString = "";
    try {
        if (isSsl) {
            // 创建Httpclient对象
            SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(
                    SSLContexts.custom().loadTrustMaterial(null, new TrustSelfSignedStrategy()).build(),
                    NoopHostnameVerifier.INSTANCE);
            httpClient = HttpClients.custom().setSSLSocketFactory(sslsf).build();
        } else {
            // 创建Httpclient对象
            httpClient = HttpClients.createDefault();
        }
        // 创建Http Post请求
        HttpPost httpPost = new HttpPost(url);
        RequestConfig requestConfig = RequestConfig.custom().setConnectionRequestTimeout(connectTimeout)
                .setSocketTimeout(connectTimeout).setConnectTimeout(connectTimeout).build();
        httpPost.setConfig(requestConfig);
        // 创建请求内容
        StringEntity entity = new StringEntity(json, ContentType.APPLICATION_JSON);
        httpPost.setEntity(entity);
        // 执行http请求
        response = httpClient.execute(httpPost);
        resultString = EntityUtils.toString(response.getEntity(), "utf-8");
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            response.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    return resultString;
}

 第三步：使用例子

@Override
public void syncUnicomUser() {
    //获取token
    String tokenJsonString = HttpClientUtil.doPost(unicomTokenConfig.getUrl(),unicomTokenConfig.getTokenParam());
    JSONObject tokenJsonData = JSONObject.parseObject(tokenJsonString);
    JSONObject rspJsonData = tokenJsonData.getJSONObject("RSP");
    String token = rspJsonData.getString("DATA");
    //删除旧数据
    this.remove(Wrappers.<UnicomUserInfo>query());
    //分页获取用户详情
    int page = 1;
    while (true) {
        String basicInfoJsonString = HttpClientUtil.doGet(unicomBasicInfoConfig.getUrl(),unicomBasicInfoConfig.getBasicInfoParam(token,page));
        JSONObject basicInfoJsonData = JSONObject.parseObject(basicInfoJsonString);
        rspJsonData = basicInfoJsonData.getJSONObject("RSP");
        JSONObject dataJsonData = rspJsonData.getJSONObject("DATA");
        JSONArray dataJsonArrayData = dataJsonData.getJSONArray("rows");
        if (dataJsonArrayData!=null&&dataJsonArrayData.size()>0) {
            List<UnicomUserInfo> unicomUserInfoList = JSONArray.parseArray(dataJsonArrayData.toJSONString(),UnicomUserInfo.class);
            this.saveBatch(unicomUserInfoList);
            page++;
        } else {
            break;
        }
    }
    syncSysUser();
}