java文件
不带参的写法:
package xxx.xxx.xxx;
import com.sun.javafx.webkit.CursorManagerImpl;
import com.sun.xml.internal.ws.policy.privateutil.PolicyUtils;
import org.apache.http.HttpEntity;
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;
import org.apache.http.util.EntityUtils;
import java.io.IOException;
public class crawlerFirst {
public static void main(String[] args) {
//1. 打开浏览器,创建HTTPClient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
//2.输入网址,发起get请求创建HttpGet对象
HttpGet httpGet = new HttpGet("http://www.itcast.cn");
//3.按回车,发起请求,返回响应,使用HTTPClient对象发起请求
CloseableHttpResponse response = null;
try{
response = httpClient.execute(httpGet);
//4.解析响应,获取数据
if( response.getStatusLine().getStatusCode() == 200){
HttpEntity httpEntity = response.getEntity();
String content = EntityUtils.toString(httpEntity, "utf8");
System.out.println(content);
}
}catch(IOException e){
e.printStackTrace();
}finally {
//关闭response
try{
response.close();
}catch(IOException e){
e.printStackTrace();
}
try{
httpClient.close();
}catch(IOException e){
e.printStackTrace();
}
}
}
}
运行结果:
带参数的写法:
用到了URIBuilder
这个类
package xxx.xxx.xxx;
import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
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.util.EntityUtils;
import java.io.IOException;
import java.net.URISyntaxException;
public class HttpGetParamTest {
public static void main(String[] args) throws Exception {
//1. 打开浏览器,创建HTTPClient对象
CloseableHttpClient httpClient = HttpClients.createDefault();
// 设置请求地址是:http://yun.itheima.com/search?keys=Java
// 创建URIBuilder
URIBuilder uriBuilder = new URIBuilder("http://yun.itheima.com/search?keys=Java");
uriBuilder.setParameter("keys","Java");
//2.输入网址,发起get请求创建HttpGet对象
HttpGet httpGet = new HttpGet(uriBuilder.build());
System.out.println("发送请求的信息:"+httpGet);
//3.按回车,发起请求,返回响应,使用HTTPClient对象发起请求
CloseableHttpResponse response = null;
try{
response = httpClient.execute(httpGet);
//4.解析响应,获取数据
if( response.getStatusLine().getStatusCode() == 200){
HttpEntity httpEntity = response.getEntity();
String content = EntityUtils.toString(httpEntity, "utf8");
System.out.println(content);
}
}catch(IOException e){
e.printStackTrace();
}finally {
//关闭response
try{
response.close();
}catch(IOException e){
e.printStackTrace();
}
try{
httpClient.close();
}catch(IOException e){
e.printStackTrace();
}
}
}
}
效果截图: