HttpClient Java工具类

超、凢脫俗 2024-03-17 21:51 26阅读 0赞

#### 1. 介绍 ####

HttpClient 是Apache Jakarta Common 下的子项目，可以用来提供高效的、最新的、功能丰富的支持 HTTP 协议的客户端编程工具包，并且它支持 HTTP 协议最新的版本和建议。

**核心API：**

*  HttpClient：Http客户端对象类型，使用该类型对象可发起Http请求。
 *  HttpClients：可认为是构建器，可创建HttpClient对象。
 *  CloseableHttpClient：实现类，实现了HttpClient接口。
 *  HttpGet：Get方式请求类型。
 *  HttpPost：Post方式请求类型。

#### 2. **实现步骤** ####

1.  创建HttpClient对象
2.  创建请求对象
3.  发送请求，接受响应结果
4.  解析结果
5.  关闭资源

##### 2.1 **HttpClient的maven坐标：** #####

<dependency>
    	<groupId>org.apache.httpcomponents</groupId>
    	<artifactId>httpclient</artifactId>
    	<version>4.5.13</version>
    </dependency>

##### 2.2 HttpClientUtil .java 工具类 #####

package com.zsx.utils;
    
    import com.alibaba.fastjson.JSONObject;
    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.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;
    
    /**
     * Http工具类
     */
    public class HttpClientUtil {
        
    
        static final  int TIMEOUT_MSEC = 5 * 1000;
    
        /**
         * 发送GET方式请求
         * @param url
         * @param paramMap
         * @return
         */
        public static String doGet(String url,Map<String,String> paramMap){
        
            // 创建Httpclient对象
            CloseableHttpClient httpClient = HttpClients.createDefault();
    
            String result = "";
            CloseableHttpResponse response = null;
    
            try{
        
                URIBuilder builder = new URIBuilder(url);
                if(paramMap != null){
        
                    for (String key : paramMap.keySet()) {
        
                        builder.addParameter(key,paramMap.get(key));
                    }
                }
                URI uri = builder.build();
    
                //创建GET请求
                HttpGet httpGet = new HttpGet(uri);
    
                //发送请求
                response = httpClient.execute(httpGet);
    
                //判断响应状态
                if(response.getStatusLine().getStatusCode() == 200){
        
                    result = EntityUtils.toString(response.getEntity(),"UTF-8");
                }
            }catch (Exception e){
        
                e.printStackTrace();
            }finally {
        
                try {
        
                    response.close();
                    httpClient.close();
                } catch (IOException e) {
        
                    e.printStackTrace();
                }
            }
    
            return result;
        }
    
        /**
         * 发送POST方式请求
         * @param url
         * @param paramMap
         * @return
         * @throws IOException
         */
        public static String doPost(String url, Map<String, String> paramMap) throws IOException {
        
            // 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 (paramMap != null) {
        
                    List<NameValuePair> paramList = new ArrayList();
                    for (Map.Entry<String, String> param : paramMap.entrySet()) {
        
                        paramList.add(new BasicNameValuePair(param.getKey(), param.getValue()));
                    }
                    // 模拟表单
                    UrlEncodedFormEntity entity = new UrlEncodedFormEntity(paramList);
                    httpPost.setEntity(entity);
                }
    
                httpPost.setConfig(builderRequestConfig());
    
                // 执行http请求
                response = httpClient.execute(httpPost);
    
                resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
            } catch (Exception e) {
        
                throw e;
            } finally {
        
                try {
        
                    response.close();
                } catch (IOException e) {
        
                    e.printStackTrace();
                }
            }
    
            return resultString;
        }
    
        /**
         * 发送POST方式请求
         * @param url
         * @param paramMap
         * @return
         * @throws IOException
         */
        public static String doPost4Json(String url, Map<String, String> paramMap) throws IOException {
        
            // 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);
    
                if (paramMap != null) {
        
                    //构造json格式数据
                    JSONObject jsonObject = new JSONObject();
                    for (Map.Entry<String, String> param : paramMap.entrySet()) {
        
                        jsonObject.put(param.getKey(),param.getValue());
                    }
                    StringEntity entity = new StringEntity(jsonObject.toString(),"utf-8");
                    //设置请求编码
                    entity.setContentEncoding("utf-8");
                    //设置数据类型
                    entity.setContentType("application/json");
                    httpPost.setEntity(entity);
                }
    
                httpPost.setConfig(builderRequestConfig());
    
                // 执行http请求
                response = httpClient.execute(httpPost);
    
                resultString = EntityUtils.toString(response.getEntity(), "UTF-8");
            } catch (Exception e) {
        
                throw e;
            } finally {
        
                try {
        
                    response.close();
                } catch (IOException e) {
        
                    e.printStackTrace();
                }
            }
    
            return resultString;
        }
        private static RequestConfig builderRequestConfig() {
        
            return RequestConfig.custom()
                    .setConnectTimeout(TIMEOUT_MSEC)
                    .setConnectionRequestTimeout(TIMEOUT_MSEC)
                    .setSocketTimeout(TIMEOUT_MSEC).build();
        }
    
    }

##### 2.3 使用工具类发送请求 #####

1.  **GET方式请求**

package com.sky.test;
    
    import org.apache.http.HttpEntity;
    import org.apache.http.client.methods.CloseableHttpResponse;
    import org.apache.http.client.methods.HttpGet;
    import org.apache.http.impl.client.CloseableHttpClient;
    import org.apache.http.impl.client.HttpClients;
    import org.apache.http.util.EntityUtils;
    import org.junit.jupiter.api.Test;
    import org.springframework.boot.test.context.SpringBootTest;
    
    @SpringBootTest
    public class HttpClientTest {
        
    
        /**
         * 测试通过httpclient发送GET方式的请求
         */
        @Test
        public void testGET() throws Exception{
        
            //创建httpclient对象
            CloseableHttpClient httpClient = HttpClients.createDefault();
    
            //创建请求对象
            HttpGet httpGet = new HttpGet("http://localhost:8080/user/shop/status");
    
            //发送请求，接受响应结果
            CloseableHttpResponse response = httpClient.execute(httpGet);
    
            //获取服务端返回的状态码
            int statusCode = response.getStatusLine().getStatusCode();
            System.out.println("服务端返回的状态码为：" + statusCode);
    
            HttpEntity entity = response.getEntity();
            String body = EntityUtils.toString(entity);
            System.out.println("服务端返回的数据为：" + body);
    
            //关闭资源
            response.close();
            httpClient.close();
        }
    }

1.  **POST方式请求**

/**
         * 测试通过httpclient发送POST方式的请求
         */
        @Test
        public void testPOST() throws Exception{
        
            // 创建httpclient对象
            CloseableHttpClient httpClient = HttpClients.createDefault();
    
            //创建请求对象
            HttpPost httpPost = new HttpPost("http://localhost:8080/admin/employee/login");
    
            JSONObject jsonObject = new JSONObject();
            jsonObject.put("username","admin");
            jsonObject.put("password","123456");
    
            StringEntity entity = new StringEntity(jsonObject.toString());
            //指定请求编码方式
            entity.setContentEncoding("utf-8");
            //数据格式
            entity.setContentType("application/json");
            httpPost.setEntity(entity);
    
            //发送请求
            CloseableHttpResponse response = httpClient.execute(httpPost);
    
            //解析返回结果
            int statusCode = response.getStatusLine().getStatusCode();
            System.out.println("响应码为：" + statusCode);
    
            HttpEntity entity1 = response.getEntity();
            String body = EntityUtils.toString(entity1);
            System.out.println("响应数据为：" + body);
    
            //关闭资源
            response.close();
            httpClient.close();
        }
        ```