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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<NameValuePair> parameters = new ArrayList<NameValuePair>(); 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:
<dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> <version>4.3.5</version> </dependency>
【2】spirng配置文件applicationContext-httpclient.xml:
<!-- 定义httpClient连接管理器 --> <bean id="httpClientConnectionManager" class="org.apache.http.impl.conn.PoolingHttpClientConnectionManager"> <property name="maxTotal" value="${http.maxTotal}" /> <property name="defaultMaxPerRoute" value="${http.defaultMaxPerRoute}" /> </bean> <!-- httpclient的构建器 --> <bean id="httpClientBuilder" class="org.apache.http.impl.client.HttpClientBuilder"> <property name="connectionManager" ref="httpClientConnectionManager" /> </bean> <!-- 定义Httpclient对象。注意:该对象是多例的! --> <bean class="org.apache.http.impl.client.CloseableHttpClient" factory-bean="httpClientBuilder" factory-method="build" scope="prototype"> </bean> <!-- 请求参数的构建器 --> <bean id="requestConfigBuilder" class="org.apache.http.client.config.RequestConfig.Builder"> <!-- 创建连接的最长时间 --> <property name="connectTimeout" value="${http.connectTimeout}" /> <!-- 从连接池中获取到连接的最长时间 --> <property name="connectionRequestTimeout" value="${http.connectionRequestTimeout}" /> <!-- 数据传输的最长时间 --> <property name="socketTimeout" value="${http.socketTimeout}" /> <!-- 提交请求前测试连接是否可用 --> <property name="staleConnectionCheckEnabled" value="${http.staleConnectionCheckEnabled}" /> </bean> <!-- 定义请求参数对象 --> <bean class="org.apache.http.client.config.RequestConfig" factory-bean="requestConfigBuilder" factory-method="build" /> <!-- 定期关闭无效的连接 --> <bean class="com.jxn.common.httpclient.IdleConnectionEvictor"> <constructor-arg index="0" ref="httpClientConnectionManager" /> </bean> 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<String, String> params) throws ClientProtocolException, IOException, URISyntaxException { URIBuilder builder = new URIBuilder(url); for (Map.Entry<String, String> 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<String, String> params) throws IOException { // 创建http POST请求 HttpPost httpPost = new HttpPost(url); httpPost.setConfig(requestConfig); if (null != params) { List<NameValuePair> parameters = new ArrayList<NameValuePair>(0); for (Map.Entry<String, String> 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!这里是亿速云网站,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!
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