一、简介
HttpClient 是Apache Jakarta Common 下的子项目，可以用来提供高效的、最新的、功能丰富的支持 HTTP 协议的客户端编程工具包，并且它支持 HTTP 协议最新的版本和建议。详细介绍，此处基于4.5.2版本。maven依赖：
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.2</version>
</dependency>
二、HelloWorld实现
package com.xsjt.chap01; 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.HttpClients;
import org.apache.http.util.EntityUtils; public class HelloWorld { /**
* 抓取网页信息使用 get请求
* @param args
* @throws IOException
* @throws ClientProtocolException
*/
public static void main(String[] args) throws ClientProtocolException, IOException {
// 创建httpClient实例
CloseableHttpClient httpClient = HttpClients.createDefault();
// 创建httpGet实例
HttpGet httpGet = new HttpGet("http://www.cnblogs.com"); // http://www.tuicool.com/
CloseableHttpResponse response = httpClient.execute(httpGet);
if(response != null){
HttpEntity entity = response.getEntity(); // 获取网页内容
String result = EntityUtils.toString(entity, "UTF-8");
System.out.println("网页内容：" + result);
}
if(response != null){
response.close();
}
if(httpClient != null){
httpClient.close();
}
}
}
上述代码中可以直接获取到 网页内容，有的获取到的内容是 中文乱码的，这就需要根据 网页的编码 来设置编码了，比如gb2312。
三、爬虫教程
https://www.kancloud.cn/johnnylee/crawler/