HttpClient发送GET请求和POST请求

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原创最新推荐文章于 2026-04-23 22:24:36 发布 2.4k 阅读 AI 写同款· GEO 优化 ›

使用Apache HttpClient访问JSP发送GET和POST请求本示例说明了如何使用Apache HttpClient发送GET和POST请求，以及如何发送表单数据，详见代码及说明。对于ASP.NET的网站请求，可以查看使用Apache HttpClient访问ASP.NET发送GET和POST请求说明： 1、发送表单POST请求时，需要借助HttpWatch或有这种功能的小工具来查看发给服务器的参数有哪些； 2、对于POST请求的表单数据，需要... 阅读详情

一、描述

日常开发过程中，对接三方接口，我们需要调用外围系统的接口，那此时就需要使用工具类调用别的系统的接口，本文主要提供HttpClient来调用接口。

二、需要的jar包

httpclient-4.5.2、

httpcore-4.4.5

jdk的jre包

lombok 1.6.18（可选）

slf4(可选)

三、源码展示

1.GET请求

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

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

        // 返回结果
        String resultString = "";

        // 执行url之后的响应
        CloseableHttpResponse response = null;

        try {
            // 创建uri
            URIBuilder builder = new URIBuilder(url);

            // 将参数封装到uri里面
            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) {
            log.info(e.getMessage());
        }
        finally {
            try {
                if (response != null) {
                    response.close();
                }
                httpclient.close();
            }
            catch (IOException e) {
                log.info(e.getMessage());
            }
        }
        return resultString;
    }

2. POST请求

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) {
            log.info(e.getMessage());
        }
        finally {
            try {
                response.close();
            }
            catch (IOException e) {
                // TODO Auto-generated catch block
                log.info(e.getMessage());
            }
        }

        return resultString;
    }

3.POST提交JSON类型参数

 /**
     * 以JSON方式发请求
     *
     * @param url
     * @param json
     * @return
     */
    public static String doPostJson(String url, String json, int connectTimeOut, int socketTimeOut) {
        // 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);
            RequestConfig requestConfig = RequestConfig.custom()
                    .setConnectTimeout(connectTimeOut).setSocketTimeout(socketTimeOut).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) {
            log.info(e.getMessage());
        }
        finally {
            try {
                response.close();
            }
            catch (IOException e) {
                // TODO Auto-generated catch block
                log.info(e.getMessage());
            }
        }

        return resultString;
    }

4.全部源码奉上

package com.yang.utils;

import lombok.extern.slf4j.Slf4j;
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.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;

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

@Slf4j
public class HttpRequest {


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

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

        // 返回结果
        String resultString = "";

        // 执行url之后的响应
        CloseableHttpResponse response = null;

        try {
            // 创建uri
            URIBuilder builder = new URIBuilder(url);

            // 将参数封装到uri里面
            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) {
            log.info(e.getMessage());
        }
        finally {
            try {
                if (response != null) {
                    response.close();
                }
                httpclient.close();
            }
            catch (IOException e) {
                log.info(e.getMessage());
            }
        }
        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) {
            log.info(e.getMessage());
        }
        finally {
            try {
                response.close();
            }
            catch (IOException e) {
                // TODO Auto-generated catch block
                log.info(e.getMessage());
            }
        }

        return resultString;
    }

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

    /**
     * 以JSON方式发请求
     *
     * @param url
     * @param json
     * @return
     */
    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) {
            log.info(e.getMessage());
        }
        finally {
            try {
                response.close();
            }
            catch (IOException e) {
                // TODO Auto-generated catch block
                log.info(e.getMessage());
            }
        }

        return resultString;
    }
    /**
     * 以JSON方式发请求
     *
     * @param url
     * @param json
     * @return
     */
    public static String doPostJson(String url, String json, int connectTimeOut, int socketTimeOut) {
        // 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);
            RequestConfig requestConfig = RequestConfig.custom()
                    .setConnectTimeout(connectTimeOut).setSocketTimeout(socketTimeOut).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) {
            log.info(e.getMessage());
        }
        finally {
            try {
                response.close();
            }
            catch (IOException e) {
                // TODO Auto-generated catch block
                log.info(e.getMessage());
            }
        }

        return resultString;
    }
}

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