HttpClient的使用实例

本篇内容主要讲解"HttpClient的使用实例"，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习"HttpClient的使用实例"吧!

HttpClient的使用：

1）httpClient的简单使用：

import java.net.URI;import java.util.ArrayList;import java.util.List;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.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.message.BasicNameValuePair;import org.apache.http.util.EntityUtils;public class HttpClientDemo {        public static void main(String[] args) throws Exception {                // 1.创建Httpclient对象                CloseableHttpClient httpclient = HttpClients.createDefault();                // 2.1创建http GET请求，并设置参数                String url = "http://www.jxn.com/";                URI uri = new URIBuilder(url).setParameter("name", "jack").setParameter("age", "1").build();                HttpGet httpGet = new HttpGet(uri);                // 2.2创建http POST请求，并设置参数                HttpPost httpPost = new HttpPost(url);                List parameters = new ArrayList();                parameters.add(new BasicNameValuePair("name", "jack"));                parameters.add(new BasicNameValuePair("age", "1"));                UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(parameters);                httpPost.setEntity(formEntity);                                                // 3.构建请求配置信息                RequestConfig config = RequestConfig.custom().setConnectTimeout(1000) // 创建连接的最长时间                                .setConnectionRequestTimeout(500) // 从连接池中获取到连接的最长时间                                .setSocketTimeout(10 * 1000) // 数据传输的最长时间                                .setStaleConnectionCheckEnabled(true) // 提交请求前测试连接是否可用                                .build();                httpGet.setConfig(config);                httpPost.setConfig(config);                CloseableHttpResponse response = null;                try {                        // 4.执行请求                        response = httpclient.execute(httpGet);//            response = httpclient.execute(httpPost);                                                                        if (response.getStatusLine().getStatusCode() == 200) { // 判断返回状态是否为200                                String content = EntityUtils.toString(response.getEntity(), "UTF-8");                                System.out.println(content);                        }                       } finally {                        if (response != null) {                                response.close();                        }                        httpclient.close();                }        }}

2）使用httpClient连接池：

import org.apache.http.client.methods.CloseableHttpResponse;import org.apache.http.client.methods.HttpGet;import org.apache.http.conn.HttpClientConnectionManager;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;import org.apache.http.util.EntityUtils;public class HttpClientConnectionManagerDemo {        public static void main(String[] args) throws Exception {                PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();                connectionManager.setMaxTotal(200);                        // 设置最大连接数                connectionManager.setDefaultMaxPerRoute(20);       // 设置每个主机地址的并发数                // 执行一次get请求                doGet(connectionManager);        }        public static void doGet(HttpClientConnectionManager connectionManager) throws Exception {                CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(connectionManager).build();                String url = "http://www.jxn.com/";                HttpGet httpGet = new HttpGet(url);                CloseableHttpResponse response = null;                try {                        response = httpClient.execute(httpGet);                        if (response.getStatusLine().getStatusCode() == 200) {                                String content = EntityUtils.toString(response.getEntity(), "UTF-8");                                System.out.println(content);                        }                } finally {                        if (response != null) {                                response.close();                        }                        // 此处不能关闭httpClient！如果把httpClient关闭掉，则连接池也会被销毁                        // httpClient.close();                }        }}

3）HttpClient与Spring整合：

【1】pom.xml文件：

        org.apache.httpcomponents        httpclient        4.3.5

【2】spirng配置文件applicationContext-httpclient.xml：

                                                                                                属性配置文件httpclient.properties：        http.maxTotal=200        http.defaultMaxPerRoute=50        http.connectTimeout=1000        http.connectionRequestTimeout=500        http.socketTimeout=10000        http.staleConnectionCheckEnabled=true

【3】封装成Service：

import java.io.IOException;import java.net.URISyntaxException;import java.util.ArrayList;import java.util.List;import java.util.Map;import org.apache.http.NameValuePair;import org.apache.http.client.ClientProtocolException;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.message.BasicNameValuePair;import org.apache.http.util.EntityUtils;import org.springframework.beans.BeansException;import org.springframework.beans.factory.BeanFactory;import org.springframework.beans.factory.BeanFactoryAware;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import com.jxn.common.httpclient.HttpResult;[@Service](https://my.oschina.net/service)public class ApiService implements BeanFactoryAware {        private BeanFactory beanFactory;        @Autowired(required = false)        private RequestConfig requestConfig;                        [@Override](https://my.oschina.net/u/1162528)        public void setBeanFactory(BeanFactory beanFactory) throws BeansException {                this.beanFactory = beanFactory;        }        private CloseableHttpClient getHttpClient() {                return this.beanFactory.getBean(CloseableHttpClient.class);        }                // 执行GET请求        public String doGet(String url) throws ClientProtocolException, IOException {                HttpGet httpGet = new HttpGet(url);                httpGet.setConfig(requestConfig);                CloseableHttpResponse response = null;                try {                        // 执行请求                        response = getHttpClient().execute(httpGet);                        // 判断返回状态是否为200                        if (response.getStatusLine().getStatusCode() == 200) {                                return EntityUtils.toString(response.getEntity(), "UTF-8");                        }                } finally {                        if (response != null) {                                response.close();                        }                }                return null;        }        // 带有参数的GET请求        public String doGet(String url, Map params) throws ClientProtocolException, IOException,                        URISyntaxException {                URIBuilder builder = new URIBuilder(url);                for (Map.Entry entry : params.entrySet()) {                        builder.setParameter(entry.getKey(), entry.getValue());                }                return doGet(builder.build().toString());        }        // 执行post请求        public HttpResult doPost(String url, Map params) throws IOException {                // 创建http POST请求                HttpPost httpPost = new HttpPost(url);                httpPost.setConfig(requestConfig);                if (null != params) {                        List parameters = new ArrayList(0);                        for (Map.Entry entry : params.entrySet()) {                                parameters.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));                        }                        // 构造一个form表单式的实体                        UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(parameters, "UTF-8");                        httpPost.setEntity(formEntity);                }                CloseableHttpResponse response = null;                try {                        response = getHttpClient().execute(httpPost);                        return new HttpResult(response.getStatusLine().getStatusCode(), EntityUtils.toString(                                        response.getEntity(), "UTF-8"));                } finally {                        if (response != null) {                                response.close();                        }                }        }        // 执行post请求，发送json数据        public HttpResult doPostJson(String url, String json) throws IOException {                // 创建http POST请求                HttpPost httpPost = new HttpPost(url);                httpPost.setConfig(requestConfig);                if (null != json) {                        // 构造一个字符串的实体                        StringEntity stringEntity = new StringEntity(json, ContentType.APPLICATION_JSON);                        httpPost.setEntity(stringEntity);                }                CloseableHttpResponse response = null;                try {                        response = getHttpClient().execute(httpPost);                        return new HttpResult(response.getStatusLine().getStatusCode(), EntityUtils.toString(                                        response.getEntity(), "UTF-8"));                } finally {                        if (response != null) {                                response.close();                        }                }        }}// 返回的结果public class HttpResult {        private Integer code;        private String data;        public HttpResult() {        }        public HttpResult(Integer code, String data) {                this.code = code;                this.data = data;        }        public Integer getCode() {                return code;        }        public void setCode(Integer code) {                this.code = code;        }        public String getData() {                return data;        }        public void setData(String data) {                this.data = data;        }}

【4】实现定期关闭无效的连接：

import org.apache.http.conn.HttpClientConnectionManager;public class IdleConnectionEvictor extends Thread {        private final HttpClientConnectionManager connectionManager;        private volatile boolean shutdown;        // 创建IdleConnectionEvictor对象的时候，启动线程        public IdleConnectionEvictor(HttpClientConnectionManager connectionManager) {                this.connectionManager = connectionManager;                this.start();        }        [@Override](https://my.oschina.net/u/1162528)        public void run() {                try {                        while (!shutdown) {                                synchronized (this) {                                        wait(5000);                                        // 关闭失效的连接(每隔5秒检查一次)                                        connectionManager.closeExpiredConnections();                                }                        }                } catch (InterruptedException ex) {                        // 结束                }        }        public void shutdown() {                shutdown = true;                synchronized (this) {                        notifyAll();                }        }}

到此，相信大家对"HttpClient的使用实例"有了更深的了解，不妨来实际操作一番吧！这里是网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！