org.apache.httpcomponents:httpclient 工具类

基于httpclient 版本4.4.1

因为http连接需要三次握手，在需要频繁调用时浪费资源和时间

故采用连接池的方式连接

　　根据实际需要更改  连接池最大连接数、路由最大连接数

　　另一个需要注意的是

 

　　　// 释放Socket流
     response.close();
     // 释放Connection
     // httpClient.close();

import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.config.RequestConfig;
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.config.SocketConfig;
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 java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.Map;

/**
 * Created by lidada on 2017/6/9.
 */
public class HttpClientUtils {
    private static PoolingHttpClientConnectionManager cm;
    private static String EMPTY_STR = "";
    private static String CONTENT_TYPE_UTF_8 = "UTF-8";
    private static String CONTENT_TYPE_GBK = "GBK";
    private static String CONTENT_TYPE_JSON = "application/json";
    private static final int CONNECTION_TIMEOUT_MS = 60000;
    private static final int SO_TIMEOUT_MS = 60000;

    private static void init() {
        if (cm == null) {
            cm = new PoolingHttpClientConnectionManager();
            cm.setMaxTotal(50);// 整个连接池最大连接数
            cm.setDefaultMaxPerRoute(5);// 每路由最大连接数，默认值是2
            SocketConfig sc = SocketConfig.custom().setSoTimeout(SO_TIMEOUT_MS).build();
            cm.setDefaultSocketConfig(sc);
        }
    }

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

    public static String httpGetRequest(String url) {
        HttpGet httpGet = new HttpGet(url);
        return getResult(httpGet);
    }

    public static String httpGetRequest(String url, Map<String, Object> params) throws URISyntaxException {
        URIBuilder ub = new URIBuilder();
        ub.setPath(url);

        ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
        ub.setParameters(pairs);

        HttpGet httpGet = new HttpGet(ub.build());
        return getResult(httpGet);
    }

    public static String httpGetRequest(String url, Map<String, Object> headers, Map<String, Object> params)
            throws URISyntaxException {
        URIBuilder ub = new URIBuilder();
        ub.setPath(url);

        ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
        ub.setParameters(pairs);

        HttpGet httpGet = new HttpGet(ub.build());
        for (Map.Entry<String, Object> param : headers.entrySet()) {
            httpGet.addHeader(param.getKey(), String.valueOf(param.getValue()));
        }
        return getResult(httpGet);
    }

    public static String httpPostRequest(String url) {
        HttpPost httpPost = new HttpPost(url);
        return getResult(httpPost);
    }

    public static String httpPostRequest(String url, Map<String, Object> params) throws UnsupportedEncodingException {
        HttpPost httpPost = new HttpPost(url);
        ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
        httpPost.setEntity(new UrlEncodedFormEntity(pairs, CONTENT_TYPE_UTF_8));
        return getResult(httpPost);
    }

    public static String httpPostRequest(String url, Map<String, Object> headers, Map<String, Object> params)
            throws UnsupportedEncodingException {
        HttpPost httpPost = new HttpPost(url);

        for (Map.Entry<String, Object> param : headers.entrySet()) {
            httpPost.addHeader(param.getKey(), String.valueOf(param.getValue()));
        }

        ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
        httpPost.setEntity(new UrlEncodedFormEntity(pairs, CONTENT_TYPE_UTF_8));

        return getResult(httpPost);
    }

    public static String httpPostJSON(String url, String json) throws UnsupportedEncodingException {
        HttpPost httpPost = new HttpPost(url);
        StringEntity s = new StringEntity(json);
        s.setContentEncoding(CONTENT_TYPE_UTF_8);
        s.setContentType(CONTENT_TYPE_JSON);// 发送json数据需要设置contentType
        httpPost.setEntity(s);
        return getResult(httpPost);
    }


    private static ArrayList<NameValuePair> covertParams2NVPS(Map<String, Object> params) {
        ArrayList<NameValuePair> pairs = new ArrayList<>();
        for (Map.Entry<String, Object> param : params.entrySet()) {
            pairs.add(new BasicNameValuePair(param.getKey(), String.valueOf(param.getValue())));
        }

        return pairs;
    }

    /**
     * 处理Http请求
     *
     * @param request
     * @return
     */
    private static String getResult(HttpRequestBase request) {

        RequestConfig.Builder config = RequestConfig.copy(RequestConfig.DEFAULT);
        config.setConnectionRequestTimeout(CONNECTION_TIMEOUT_MS);
        config.setSocketTimeout(SO_TIMEOUT_MS);

        request.setConfig(config.build());

        // CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpClient httpClient = getHttpClient();
        CloseableHttpResponse response = null;
        try {
            response = httpClient.execute(request);
            // response.getStatusLine().getStatusCode();
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                // long len = entity.getContentLength();// -1 表示长度未知
                return EntityUtils.toString(entity);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                // 释放Socket流
                response.close();
                // 释放Connection
                // httpClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return EMPTY_STR;
    }

}