基于 org.apache.http.client 访问http接口

最新推荐文章于 2025-07-01 11:14:23 发布

原创最新推荐文章于 2025-07-01 11:14:23 发布 · 2k 阅读

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本文介绍如何使用HttpClient工具包调用HTTP接口，并实现JSON反序列化处理。文章提供了基于连接池的HttpClient配置方法，以及GET、POST请求的具体实现示例。

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背景

虽然有了dubbo提供的服务接口，但是在项目与项目之间仍旧存在着http访问的接口。那么怎么调用呢？httpClient这个工具包用起来就十分的方便了。一般获取到接口返回的数据时，都需要做json反序列化为对象。可以使用spring-mvc依赖的 com.fasterxml.jackson.core。也可以使用com.alibaba.fastjson

参考资料：

https://www.cnblogs.com/sharpest/p/6406013.html

https://blog.youkuaiyun.com/xiaoxian8023/article/details/49865335

https://blog.youkuaiyun.com/xiaoxian8023/article/details/49619777

引用jar包

  <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.5</version>
        </dependency>

json的jar包，选择其中一个就可以

 <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.6</version>
        </dependency>

       <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.5</version>
        </dependency>

http进行访问的基本步骤

使用HttpClient发送请求、接收响应很简单，一般需要如下几步即可。

1. 创建HttpClient对象。一般都使用连接池来创建

2. 创建请求方法的实例，并指定请求URL。如果需要发送GET请求，创建HttpGet对象；如果需要发送POST请求，创建HttpPost对象。

3. 如果需要发送请求参数，可调用HttpGet、HttpPost共同的setParams(HetpParams params)方法来添加请求参数；对于HttpPost对象而言，也可调用setEntity(HttpEntity entity)方法来设置请求参数。

4. 调用HttpClient对象的execute(HttpUriRequest request)发送请求，该方法返回一个HttpResponse。一般HttpClient是从http连接池里获取。

5. 调用HttpResponse的getAllHeaders()、getHeaders(String name)等方法可获取服务器的响应头；调用HttpResponse的getEntity()方法可获取HttpEntity对象，该对象包装了服务器的响应内容。程序可通过该对象获取服务器的响应内容。

6. 释放连接。无论执行方法是否成功，都必须释放连接。

代码篇

连接池对象

import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.LayeredConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;

import javax.annotation.PostConstruct;
import javax.net.ssl.SSLContext;

/**
 * @author WGP
 * @description 连接池管理对象
 * @date 2018/5/6
 **/
public class HttpConnectionManager {

    PoolingHttpClientConnectionManager cm = null;
    @PostConstruct
    public void init(){
        LayeredConnectionSocketFactory sslsf = null;
        try{
            sslsf = new SSLConnectionSocketFactory(SSLContext.getDefault());

        }catch (Exception e){
            e.printStackTrace();
        }
        Registry<ConnectionSocketFactory> socketFactoryRegistry =
                RegistryBuilder.<ConnectionSocketFactory>create().register("https",sslsf)
                        .register("http",new PlainConnectionSocketFactory()).build();
        cm = new PoolingHttpClientConnectionManager(socketFactoryRegistry);
        cm.setMaxTotal(200);
        cm.setDefaultMaxPerRoute(20);
    }
    public CloseableHttpClient getHttpClient(){
        CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(cm).build();
        return httpClient;
    }
}

基本使用的方法

public class HttpClient {


    public void postJson() throws Exception {

        String url = "http:/localhost/shop";
        //1、创建http连接
        CloseableHttpClient httpClient = new HttpConnectionManager().getHttpClient();
        CloseableHttpResponse response = null;
        try {
            //2、创建请求对象
            HttpPost httpPost = new HttpPost(url);
//            3、设置请求头及数据
            httpPost.addHeader(HTTP.CONTENT_TYPE,
                    "application/x-www-form-urlencoded");
            String json = "{'ids':['html1','html2'}";
            StringEntity se = new StringEntity(json);
            se.setContentEncoding("UTF-8");
            httpPost.setEntity(se);
            //4、访问http接口
            response = httpClient.execute(httpPost);
            if(response != null && response.getStatusLine().getStatusCode() == 200){
                HttpEntity entity = response.getEntity();
                if (entity != null) {
                    String res = EntityUtils.toString(entity, "UTF-8");
                    //5、下面可以对res做json反序列化处理
                }
            }
        } catch (Exception e) {
            throw e;
        } finally {
            closeHttp(httpClient,response);
        }
    }

    public void postForm() throws Exception {
        CloseableHttpClient httpClient = new HttpConnectionManager().getHttpClient();
        CloseableHttpResponse response = null;
        try {
            String url = "your/path";
            HttpPost httpPost = new HttpPost(url);
            List<NameValuePair> formParams = new ArrayList<>(8);
            formParams.add(new BasicNameValuePair("username", "yourname"));
            formParams.add(new BasicNameValuePair("password", "pass"));
            UrlEncodedFormEntity uefEntity = new UrlEncodedFormEntity(formParams, "UTF-8");
            httpPost.setEntity(uefEntity);
            response = httpClient.execute(httpPost);
            if(response != null && response.getStatusLine().getStatusCode() == 200){
                HttpEntity entity = response.getEntity();
                if (entity != null) {
                    String res = EntityUtils.toString(entity, "UTF-8");
                    //下面可以对res做json反序列化处理
                }
            }
        } catch (Exception e) {
            throw e;
        } finally {
            closeHttp(httpClient, response);
        }
    }

    public void getRequest() throws Exception {
        CloseableHttpClient httpClient = new HttpConnectionManager().getHttpClient();
        CloseableHttpResponse response = null;
        try {
            String url = "your/get/path";
            HttpGet httpGet = new HttpGet(url);
            response = httpClient.execute(httpGet);
            if(response != null && response.getStatusLine().getStatusCode() == 200){
                HttpEntity entity = response.getEntity();
                if (entity != null) {
                    String res = EntityUtils.toString(entity, "UTF-8");
                    //下面可以对res做json反序列化处理
                }
            }
        } catch (Exception e) {
            throw e;
        } finally {
            closeHttp(httpClient, response);
        }
    }



    private void closeHttp(CloseableHttpClient httpClient, CloseableHttpResponse response) throws IOException {
        try {
            if (httpClient != null) {
                httpClient.close();
            }
            if (response != null) {
                response.close();
            }
        } catch (IOException ex) {
            throw ex;
        }
    }


}