HttpClientUtil.java

package com.bjsxt.springboothelloworld;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
     
       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
      
        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
       
         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,"utf-8");                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;    }        public static void main(String[] args) {        String url ="http://127.0.0.1:9090/shutdown";        //该url必须要使用dopost方式来发送        HttpClientUtil.doPost(url);    }}