Http方式请求get、post（带参、不带参）

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

import org.apache.http.Consts;
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.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;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


public class HttpUtil {


    private static final Logger log = LoggerFactory.getLogger(HttpUtil.class);
    private static final CloseableHttpClient httpclient = HttpClients.createDefault();
    private static final String userAgent = "Mozilla/5.0 (Windows NT 6.2; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.87 Safari/537.36";

    /** * 发送HttpGet请求 * * @param url * 请求地址 * @return 返回字符串 */
    public static String sendGet(String url) {
        String result = null;
        CloseableHttpResponse response = null;
        try {
            HttpGet httpGet = new HttpGet(url);
            httpGet.setHeader("User-Agent", userAgent);
            response = httpclient.execute(httpGet);
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                result = EntityUtils.toString(entity);
            }
        } catch (Exception e) {
            log.error("处理失败 {}" + e);
            e.printStackTrace();
        } finally {
            if (response != null) {
                try {
                    response.close();
                } catch (IOException e) {
                    log.error(e.getMessage());
                }
            }
        }
        return result;
    }

    /** * 发送HttpPost请求，参数为map * * @param url * 请求地址 * @param map * 请求参数 * @return 返回字符串 */
    public static String sendPost(String url, Map<String, String> map) {
        // 设置参数
        List<NameValuePair> formparams = new ArrayList<NameValuePair>();
        for (Map.Entry<String, String> entry : map.entrySet()) {
            formparams.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
        }
        // 编码
        UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(formparams, Consts.UTF_8);
        // 取得HttpPost对象
        HttpPost httpPost = new HttpPost(url);
        // 防止被当成攻击添加的
        httpPost.setHeader("User-Agent", userAgent);
        // 参数放入Entity
        httpPost.setEntity(formEntity);
        CloseableHttpResponse response = null;
        String result = null;
        try {
            // 执行post请求
            response = httpclient.execute(httpPost);
            // 得到entity
            HttpEntity entity = response.getEntity();
            // 得到字符串
            result = EntityUtils.toString(entity);
        } catch (IOException e) {
            log.error(e.getMessage());
        } finally {
            if (response != null) {
                try {
                    response.close();
                } catch (IOException e) {
                    log.error(e.getMessage());
                }
            }
        }
        return result;
    }


    /** * 发送HttpPost请求，参数为json字符串 * * @param url * @param jsonStr * @return */
    public static String sendPost(String url, String jsonStr) {
        String result = null;
        // 字符串编码
        StringEntity entity = new StringEntity(jsonStr, Consts.UTF_8);
        // 设置content-type
        entity.setContentType("application/json");
        HttpPost httpPost = new HttpPost(url);
        // 防止被当成攻击添加的
        httpPost.setHeader("User-Agent", userAgent);
        // 接收参数设置
        httpPost.setHeader("Accept", "application/json");
        httpPost.setEntity(entity);
        CloseableHttpResponse response = null;
        try {
            response = httpclient.execute(httpPost);
            HttpEntity httpEntity = response.getEntity();
            result = EntityUtils.toString(httpEntity);
        } catch (IOException e) {
            log.error(e.getMessage());
        } finally {
            // 关闭CloseableHttpResponse
            if (response != null) {
                try {
                    response.close();
                } catch (IOException e) {
                    log.error(e.getMessage());
                }
            }
        }
        return result;
    }

    /** * 发送不带参数的HttpPost请求 * * @param url * @return */
    public static String sendPost(String url) {
        String result = null;
        // 得到一个HttpPost对象
        HttpPost httpPost = new HttpPost(url);
        // 防止被当成攻击添加的
        httpPost.setHeader("User-Agent", userAgent);
        CloseableHttpResponse response = null;
        try {
            // 执行HttpPost请求，并得到一个CloseableHttpResponse
            response = httpclient.execute(httpPost);
            // 从CloseableHttpResponse中拿到HttpEntity
            HttpEntity entity = response.getEntity();
            // 将HttpEntity转换为字符串
            result = EntityUtils.toString(entity);
        } catch (IOException e) {
            log.error(e.getMessage());
        } finally {
            // 关闭CloseableHttpResponse
            if (response != null) {
                try {
                    response.close();
                } catch (IOException e) {
                    log.error(e.getMessage());
                }
            }
        }
        return result;
    }
}