给爬虫设置爬取时长网络不良时使用 不设置在默认时间内没爬取到会报错

发布于:2024-04-20 ⋅ 阅读:(17) ⋅ 点赞:(0)
package day02;
import org.apache.http.HttpEntity;
import org.apache.http.client.config.RequestConfig;
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 getpacong {
    public static void main(String[] args) throws IOException {
        //注意这个方法是爬取网址所有位置

        //1.打开浏览器,创建Httpclient对象
        //        CloseableHttpclient httpclient = Httpclients.createDefault();
        CloseableHttpClient aDefault = HttpClients.createDefault();

        //2.输入网址,发起get请求创建HttpGet对象 输入你需要爬取的网址
        HttpGet httpGet = new HttpGet("https://zhuanlan.zhihu.com/p/98346518");

        //------------------------------------------------------------------------------------------------------  
        
        //配置请求信息 效果是如果网络不良可以延长爬取的时间
        RequestConfig build = RequestConfig.custom().setConnectionRequestTimeout(1000)//创建连接的最长时间,单位是毫秒
                .setConnectionRequestTimeout(500)//设置获取连接的最长时间,单位是豪秒
                .setSocketTimeout(10 * 1000)//设置获取连接的最长时间,单位是豪秒
                .build();//提交
          //给请求设置请求信息
        httpGet.setConfig(build);

      //------------------------------------------------------------------------------------------------------  
        
        
        //3.按回车,发起请求,返回响应,使用httpclient对象发起请求
        CloseableHttpResponse response = aDefault.execute(httpGet);

        //4.解析响应,获取数据//判断状态码是否是200     200为正常型号  其他为异常
        if(response.getStatusLine().getStatusCode()== 200){
            //获取爬取数据
            HttpEntity httpEntity =response.getEntity();
            //将爬取数据解析为utf-8格式
            String content = EntityUtils.toString(httpEntity,"utf-8");
            //打印
            System.out.println(content);
        }
//释放资源
        response.close();
//关闭网页
        aDefault.close();
        
    }
}