httpClient发送
package com.bjpowernode.httpClient;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class httpClientSendGet {
public static void main(String args[]) throws Exception {
String channelId = "sdd";
String clientId = "123";
// 目标地址
// String url = "http://XXX.XXX.com.cn/arowana/channel/getChannelLine?channelId=" + channelId + "&clientId=" + clientId;
String url = "http://localhost:8081/Test/hello";
HttpGet httpGet = new HttpGet(url);
// 设置类型 "application/x-www-form-urlencoded" "application/json"
httpGet.setHeader("Content-Type", "application/x-www-form-urlencoded");
System.out.println("调用URL: " + httpGet.getURI());// httpClient实例化
CloseableHttpClient httpClient = HttpClients.createDefault();
// 执行请求并获取返回
HttpResponse response = httpClient.execute(httpGet);//
System.out.println("Response toString()" + response.toString());
HttpEntity entity = response.getEntity();
System.out.println("返回状态码:" + response.getStatusLine());
//得到返回数据的长度;没有该参数返回-1//
if (entity != null)
{
System.out.println("返回消息内容长度: " + entity.getContentLength());
}
// 显示结果
BufferedReader reader = new BufferedReader(new InputStreamReader(entity.getContent(), "UTF-8"));
String line = null;
StringBuffer responseSB = new StringBuffer();
while ((line = reader.readLine()) != null) {
responseSB.append(line);
}
System.out.println("返回消息:" + responseSB);
reader.close();
httpClient.close();
}
}
数据源的servlet
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import java.io.IOException;
@WebServlet("/hello")
public class Hello extends HttpServlet
{
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
//设置响应头
// response.setHeader("Access-Control-Allow-Origin","http://localhost:8080");
//跨域访问的资源允许访问,设置响应头的方式原理是
response.getWriter().println("{\"username\" : \"zhangSan\"};");
}
}