java爬虫抓取_java 爬虫抓取数据一个简单例子
java 爬虫抓取数据一个简单例子。用来备份用的。
package com.util;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
public class BbsTest {
public static void main(String[] args) {
Map map = new HashMap();
String con;
try {
for(int j=5;j<20;j++){
String url = "http://xxxxxxxxxxxxxxxx.html?page="+j;
List links = getAllLinks(url);
for(int i=1;i
if(map.get(links.get(i))==null){
map.put(links.get(i), "true");
con = GetWebContent(links.get(i),"utf-8",10000);
Document doc = Jsoup.parse(con);
String title = getTitle(doc);
String content = getContent(doc);
System.out.println(title);
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
/**
*网页抓取方法
* @param urlString 要抓取的url地址
* @param charset 网页编码方式
* @param timeout 超时时间
* @return 抓取的网页内容
* @throws IOException 抓取异常
*/
public static String GetWebContent(String urlString, final String charset, int timeout) throws IOException {
if (urlString == null || urlString.length() == 0) {
return null;
}
urlString = (urlString.startsWith("http://") || urlString.startsWith("https://")) ? urlString : ("http://" + urlString).intern();
URL url = new URL(urlString);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestProperty(
"User-Agent",
"Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727)");//增加报头，模拟浏览器，防止屏蔽
conn.setRequestProperty("Accept", "text/html");//只接受text/html类型，当然也可以接受图片,pdf,*/*任意，就是tomcat/conf/web里面定义那些
conn.setConnectTimeout(timeout);
try {
if (conn.getResponseCode() != HttpURLConnection.HTTP_OK) {
return null;
}
} catch (IOException e) {
e.printStackTrace();
return null;
}
InputStream input = conn.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(input,
charset));
String line = null;
StringBuffer sb = new StringBuffer();
while ((line = reader.readLine()) != null) {
sb.append(line).append("\r\n");
}
if (reader != null) {
reader.close();
}
if (conn != null) {
conn.disconnect();
}
return sb.toString();
}
public static String getContent(Document doc){
String content = "";
try {
String link = ".article_content";
content = doc.select(link).html();
} catch (Exception e) {
e.printStackTrace();
}
return content;
}
public static String getTitle(Document doc){
String content = "";
try {
String link = "h3";
content= doc.select(link).text();
} catch (Exception e) {
e.printStackTrace();
}
return content;
}
public static List getAllLinks(String url){
List links = new ArrayList();
try {
String con = GetWebContent(url,"utf-8",15000);
Document doc = Jsoup.parse(con);
String link = ".blog_list h1 a[class!=category]";
String href = "abs:href";
Elements ele = doc.select(link);
for (Element el : ele) {
String path = el.attr(href);
links.add(path);
}
} catch (Exception e) {
e.printStackTrace();
}
return links;
}
}