如果您手动处理HTTP响应而不是使用响应处理程序,则需要自己关闭所有http连接.本章介绍如何手动关闭连接.
手动关闭HTTP连接时,请按照下面给出的步骤&减去;
HttpClients 类的 createDefault()方法返回类 CloseableHttpClient 的对象,这是HttpClient接口的基本实现.
使用此方法,创建一个 HttpClient 对象,如下所示 :
CloseableHttpClient httpClient = HttpClients.createDefault();
启动try-finally块,写下剩下的代码try块中的程序并关闭finally块中的CloseableHttpClient对象.
CloseableHttpClient httpClient = HttpClients.createDefault(); try{ //Remaining code . . . . . . . . . . . . . . . }finally{ httpClient.close(); }
HttpGet 类表示使用URI检索给定服务器信息的HTTP GET请求.
通过传递表示URI的字符串来实例化HttpGet类来创建HTTP GET请求.
HttpGet httpGet = new HttpGet("http://www.IT屋.com/");
执行()方法 CloseableHttpClient 对象接受 HttpUriRequest (接口)对象(即HttpGet,HttpPost,HttpPut,HttpHead等)并返回响应对象.
使用给定方法执行请求 :
HttpResponse httpResponse = httpclient.execute(httpGet);
启动另一个try-finally块(嵌套在先前的try-finally),在这个try块的程序中写下剩下的代码并关闭finally块中的HttpResponse对象.
CloseableHttpClient httpclient = HttpClients.createDefault(); try{ . . . . . . . . . . . . . . CloseableHttpResponse httpresponse = httpclient.execute(httpget); try{ . . . . . . . . . . . . . . }finally{ httpresponse.close(); } }finally{ httpclient.close(); }
每当您创建/获取请求,响应流等对象时,在下一行开始尝试finally块,在try中写下剩余的代码并关闭finally块中的相应对象,如以下程序中所示 :
import java.util.Scanner; 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; public class CloseConnectionExample { public static void main(String args[])throws Exception{ //Create an HttpClient object CloseableHttpClient httpclient = HttpClients.createDefault(); try{ //Create an HttpGet object HttpGet httpget = new HttpGet("http://www.IT屋.com/"); //Execute the Get request CloseableHttpResponse httpresponse = httpclient.execute(httpget); try{ Scanner sc = new Scanner(httpresponse.getEntity().getContent()); while(sc.hasNext()) { System.out.println(sc.nextLine()); } }finally{ httpresponse.close(); } }finally{ httpclient.close(); } } }
执行上述程序时,生成以下输出 :
<!DOCTYPE html> <!--[if IE 8]><html class = "ie ie8"> <![endif]--> <!--[if IE 9]><html class = "ie ie9"> <![endif]--> <!--[if gt IE 9]><!--> <html lang = "en-US"> <!--<![endif]--> <head> <!-- Basic --> <meta charset = "utf-8"> <meta http-equiv = "X-UA-Compatible" content = "IE = edge"> <meta name = "viewport" content = "width = device-width,initial-scale = 1.0,userscalable = yes"> <link href = "https://img01.yuandaxia.cn/Content/img/tutorials/apache_httpclient/mui-rem.min.css" rel = "stylesheet" type = "text/css" /> <link rel = "stylesheet" href = "/questions/css/home.css?v = 3" /> <script src = "/questions/js/jquery.min.js"></script> <script src = "/questions/js/fontawesome.js"></script> <script src = "https://cdn.muicss.com/mui-0.9.39/js/mui.min.js"></script> </head> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <script> window.dataLayer = window.dataLayer || []; function gtag() {dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'UA-232293-17'); </script> </body> </html>