package com.qf.demo;import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;/*** GET请求示例* * @author 小明**/
public class GetDemo {public static void main(String[] args) {try {// 1. 得到访问地址的URLURL url = new URL("http://localhost:8080/Servlet/do_login.do?username=test&password=123456");// 2. 得到网络访问对象java.net.HttpURLConnectionHttpURLConnection connection = (HttpURLConnection) url.openConnection();/* 3. 设置请求参数（过期时间，输入、输出流、访问方式），以流的形式进行连接 */// 设置是否向HttpURLConnection输出connection.setDoOutput(false);// 设置是否从httpUrlConnection读入connection.setDoInput(true);// 设置请求方式connection.setRequestMethod("GET");// 设置是否使用缓存connection.setUseCaches(true);// 设置此 HttpURLConnection 实例是否应该自动执行 HTTP 重定向connection.setInstanceFollowRedirects(true);// 设置超时时间connection.setConnectTimeout(3000);// 连接
            connection.connect();// 4. 得到响应状态码的返回值 responseCodeint code = connection.getResponseCode();// 5. 如果返回值正常，数据在网络中是以流的形式得到服务端返回的数据String msg = "";if (code == 200) { // 正常响应// 从流中读取响应信息BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));String line = null;while ((line = reader.readLine()) != null) { // 循环从流中读取msg += line + "\n";}reader.close(); // 关闭流
            }// 6. 断开连接，释放资源
            connection.disconnect();// 显示响应结果
            System.out.println(msg);} catch (IOException e) {e.printStackTrace();}}
}

package com.qf.demo;import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;/*** POST请求示例* * @author 小明**/
public class PostDemo {public static void main(String[] args) {try {// 1. 获取访问地址URLURL url = new URL("http://localhost:8080/Servlet/do_login.do");// 2. 创建HttpURLConnection对象HttpURLConnection connection = (HttpURLConnection) url.openConnection();/* 3. 设置请求参数等 */// 请求方式connection.setRequestMethod("POST");// 超时时间connection.setConnectTimeout(3000);// 设置是否输出connection.setDoOutput(true);// 设置是否读入connection.setDoInput(true);// 设置是否使用缓存connection.setUseCaches(false);// 设置此 HttpURLConnection 实例是否应该自动执行 HTTP 重定向connection.setInstanceFollowRedirects(true);// 设置使用标准编码格式编码参数的名-值对connection.setRequestProperty("Content-Type","application/x-www-form-urlencoded");// 连接
            connection.connect();/* 4. 处理输入输出 */// 写入参数到请求中String params = "username=test&password=123456";OutputStream out = connection.getOutputStream();out.write(params.getBytes());out.flush();out.close();// 从连接中读取响应信息String msg = "";int code = connection.getResponseCode();if (code == 200) {BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));String line;while ((line = reader.readLine()) != null) {msg += line + "\n";}reader.close();}// 5. 断开连接
            connection.disconnect();// 处理结果
            System.out.println(msg);} catch (MalformedURLException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}
}

package com.qf.client;import java.io.IOException;import org.apache.http.HttpEntity;
import org.apache.http.client.ClientProtocolException;
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.HttpClientBuilder;
import org.apache.http.util.EntityUtils;/*** GET请求示例* * @author 小明**/
public class GetDemo {public static void main(String[] args) {// 1. 创建HttpClient对象CloseableHttpClient httpClient = HttpClientBuilder.create().build();// 2. 创建HttpGet对象HttpGet httpGet = new HttpGet("http://localhost:8080/Servlet/do_login.do?username=test&password=123456");CloseableHttpResponse response = null;try {// 3. 执行GET请求response = httpClient.execute(httpGet);System.out.println(response.getStatusLine());// 4. 获取响应实体HttpEntity entity = response.getEntity();// 5. 处理响应实体if (entity != null) {System.out.println("长度：" + entity.getContentLength());System.out.println("内容：" + EntityUtils.toString(entity));}} catch (ClientProtocolException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();} finally {// 6. 释放资源try {response.close();httpClient.close();} catch (IOException e) {e.printStackTrace();}}}
}

package com.qf.client;import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;/*** POST请求测试* * @author 小明**/
public class PostDemo {public static void main(String[] args) {// 1. 创建HttpClient对象CloseableHttpClient httpClient = HttpClientBuilder.create().build();// 2. 创建HttpPost对象HttpPost post = new HttpPost("http://localhost:8080/Servlet/do_login.do");// 3. 设置POST请求传递参数List<NameValuePair> params = new ArrayList<NameValuePair>();params.add(new BasicNameValuePair("username", "test"));params.add(new BasicNameValuePair("password", "12356"));try {UrlEncodedFormEntity entity = new UrlEncodedFormEntity(params);post.setEntity(entity);} catch (UnsupportedEncodingException e) {e.printStackTrace();}// 4. 执行请求并处理响应try {CloseableHttpResponse response = httpClient.execute(post);HttpEntity entity = response.getEntity();if (entity != null){System.out.println("响应内容：");System.out.println(EntityUtils.toString(entity));}response.close();} catch (ClientProtocolException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();} finally {// 释放资源try {httpClient.close();} catch (IOException e) {e.printStackTrace();}}}
}