httpclient使用实例

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黄瓜和土豆

最新推荐文章于 2023-10-25 21:28:33 发布

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分类专栏： Java EE 文章标签： byte null string query 服务器

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本文介绍如何使用Java的HttpClient库实现网站登录与数据查询功能，包括设置代理服务器、发送带参数的POST请求及处理响应数据。

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 import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
public class Httpclient {
     public final static void main(String[] args) throws Exception {
            DefaultHttpClient httpclient = new DefaultHttpClient();
           //设置代理服务器 
            final HttpHost proxy =new HttpHost("172.131.2.46", 8080, "http");
            httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);
            
            HttpPost httpost = new HttpPost("http://127.0.0.1:8080/test/admin.do?method=logon"); 
            //传递参数,本例中要输入用户名和密码才能进去 
            List <NameValuePair> nvps = new ArrayList <NameValuePair>();
            nvps.add(new BasicNameValuePair("userName", "admin"));
            nvps.add(new BasicNameValuePair("password", "admin"));
            httpost.setEntity(new UrlEncodedFormEntity(nvps, HTTP.UTF_8));
            HttpResponse response = httpclient.execute(httpost);
                    
            visitUrlOfSite(httpclient);
            
            // Do not feel like reading the response body 
            // Call abort on the request object 
            httpost.abort();
        }
     
        /**
         * inputStream转换byte数组
         * @param input
         * @return 流是从当前位置开始读取的
         * @throws Exception
         */
        private static byte[] transformInputstream(InputStream input)throws Exception
        {
            byte[] byt= null;
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            int b=0;       
            b = input.read();
            while( b != -1)
            {
                baos.write(b);
                b = input.read();            
            }
            byt = baos.toByteArray();
            return byt;
        }
        
        private static void visitUrlOfSite(HttpClient httpclient) throws Exception{
                HttpPost httpost = new HttpPost("http://127.0.0.1:8080/test/student/studentAction.do?method=query"); 
                HttpResponse response = httpclient.execute(httpost);
                HttpEntity entity = response.getEntity();
                System.out.println("----------------------------------------");
                System.out.println(response.getStatusLine());
                if (entity != null) {
                    System.out.println("Response content length: " +new String(transformInputstream(entity.getContent()),"gb2312"));
                }
                System.out.println("----------------------------------------");
                if (entity != null) {
                    entity.consumeContent();
                }
                httpost.abort();
        
        }
        
}
 