爬虫（Java实现）

//Robot.java
  1 package robot;
  2 import java.net.*;
  3 import java.sql.SQLException;
  4 import java.util.Random;
  5 
  6 import javax.swing.JOptionPane;
  7 
  8 import org.htmlparser.*;
  9 import org.htmlparser.filters.TagNameFilter;
 10 import org.htmlparser.tags.LinkTag;
 11 import org.htmlparser.util.NodeList;
 12 import org.htmlparser.util.ParserException;
 13 
 14 import mydb.DB;
 15 public class Robot {
 16     int ff=0;
 17     
 18     int num=0;
 19     //DB db;
 20     Robot() throws MalformedURLException, SQLException{
 21         DB.getConnect("localhost","3306","robot","root","142365");
 22         DB.getSta();
 23         String url0="http://www.youku.com";//"http://localhost";
 24      /*  DB.rs= DB.s.executeQuery("select count(*) from urls");
 25         if(DB.rs.next())
 26         {int n=DB.rs.getInt(1);
 27         System.out.println(n ); 
 28         Random random = new Random();
 29 
 30         int ran = random.nextInt();
 31         ran%=n;
 32         ran=ran>0?ran:-ran;
 33         System.out.println(ran ); 
 34         DB.rs= DB.s.executeQuery("select * from urls");
 35         int x=0;
 36         while(DB.rs.next()&&x<ran){
 37              
 38                   System.out.println(DB.rs.getString(1)+"000" ); url0=DB.rs.getString(1);
 39                   
 40               x++;
 41         }
 42        
 43         }*/
 44         //catchHref("http://localhost",num);
 45         catchHref(url0,num);
 46     }
 47     boolean isEndLegal(String str){
 48         if(str.endsWith("php")||str.endsWith("net/")||str.endsWith("com/")||str.endsWith("cn/")||str.endsWith("gov/")||str.endsWith("edu/")||str.endsWith("org/")||str.endsWith("net")||str.endsWith("com")||str.endsWith("cn")||str.endsWith("gov")||str.endsWith("edu")||str.endsWith("org")){
 49             return true;
 50         }
 51         return false;
 52     }
 53     boolean catchHref(String hreft ,int num) throws MalformedURLException {
 54         Parser     parser =null;
 55         NodeList nodelist=null;
 56         String href = "http://www.baidu.com";
 57         //db=new DB();
 58         if(ff!=0)
 59         if (!(hreft.startsWith("http")&&isEndLegal(hreft)&&!isInDatabase(hreft))) {
 60             return false;
 61         }
 62         ff=1;
 63         add(hreft);
 64         
 65             System.out.println(num);
 66             try {
 67                 parser = new Parser(hreft);
 68                 if(parser==null)return false;
 69             } catch (ParserException e) {
 70                 return false;
 71                 //e.printStackTrace();
 72             }
 73             try {
 74                 nodelist = parser.parse(null);
 75             } catch (ParserException e1) {
 76                 e1.printStackTrace();
 77             }
 78             if(nodelist==null)return false;
 79             NodeFilter filter = new TagNameFilter("A");
 80             if(filter==null)return false;
 81             nodelist = nodelist.extractAllNodesThatMatch(filter, true);
 82             if(nodelist==null)return false;
 83             for (int i = 0; i < nodelist.size(); i++) {
 84                 LinkTag link = (LinkTag) nodelist.elementAt(i);
 85                 href = link.getAttribute("href");
 86                 if(href==null)return false;
 87                 System.out.println(href );
 88                 catchHref(href,num);
 89                 
 90             }
 91             num++;
 92         return true;
 93     }
 94 void add(String str){
 95         
 96         try {
 97             DB.s.execute("insert into urls2(url)values(‘"+str+"‘);");
 98             DB.commit();
 99             System.out.println("add");
100         } catch (SQLException e) {
101             //e.printStackTrace();return ;
102             //JOptionPane.showMessageDialog(null, "数据库添加失败");
103             //System.exit(-1);
104             
105         }
106         
107         return ;
108     }
109     boolean isInDatabase(String str){
110 
111         try {
112             DB.rs= DB.s.executeQuery("select * from urls where url like‘"+str+"%‘;");
113             if(DB.rs.next()){System.out.println(DB.rs);return true;}
114         } catch (SQLException e) {
115             e.printStackTrace();
116             JOptionPane.showMessageDialog(null, "数据库查找失败");
117             System.exit(-1);
118         }
119         return false;
120     }
121     public static void main(String[] args)
122             throws MalformedURLException, ParserException, SQLException {
123         Robot robot = new Robot();
124     }
125 }

//DB.java
  1 package mydb;
  2 import java.sql.*;
  3 import java.util.ArrayList;
  4 
  5 import javax.swing.*;
  6 //import com.mysql.jdbc.Driver;
  7 public class DB {
  8     
  9     public static Connection conn = null;
 10     public static ResultSet rs = null;
 11     public static Statement s = null;
 12     public DB() {
 13         conn = null;
 14         s = null;
 15         rs=null;
 16         
 17     }
 18     /*
 19     String getResult(ResultSet rs) {
 20         String str = "Book\t\tOwnerID\tOwnerName\n";
 21         // System.out.println("\nno\tname\tsex\tsalary");
 22         try {
 23             while (rs.next()) {
 24                 StringBuilder builder = new StringBuilder(rs.getString(1));
 25                 builder.append("\t\t");
 26                 builder.append(rs.getString(2));
 27                 builder.append("\t");
 28                 builder.append(rs.getString(3));
 29                 builder.append("\n");
 30                 str += builder.toString();
 31             }
 32         } catch (Throwable e) {
 33 
 34         }
 35         // System.out.println();
 36         return str;
 37     }*/
 38 
 39     public static Connection getConnect(String IP,String port,String database,String user,String password){
 40         try {
 41             // Class.forName("org.gjt.mm.mysql.Driver").newInstance();
 42             Class.forName("com.mysql.jdbc.Driver");
 43         } catch (ClassNotFoundException e1) {
 44             e1.printStackTrace();
 45             JOptionPane.showMessageDialog(null, "数据库包未找到");
 46             System.exit(-1);
 47         } // .newInstance();
 48         
 49         try {
 50             conn = DriverManager.getConnection(
 51                     "jdbc:mysql://"+IP+":"+port+"/"+database+"?useUnicode=true&characterEncoding=utf8", user,
 52                     password);//autoReconnect=true&useUnicode=true&characterEncoding=utf8
 53         } catch (SQLException e1) {
 54             e1.printStackTrace();
 55             JOptionPane.showMessageDialog(null, "数据库无法连接");
 56             System.exit(-1);
 57         }
 58         
 59         try {
 60             conn.setAutoCommit(false);
 61         } catch (SQLException e1) {
 62 
 63             e1.printStackTrace();
 64         }
 65 
 66         return conn;
 67     }
 68     public static Statement getSta(){
 69         try {
 70             s = conn.createStatement();
 71         } catch (SQLException e1) {
 72 
 73             e1.printStackTrace();
 74             JOptionPane.showMessageDialog(null, "无法建立数据库语句");
 75             System.exit(-1);
 76         }
 77         return s;
 78     }
 79     
 80     
 81     public    static int commit(){
 82         try {
 83             conn.commit();
 84         } catch (SQLException e) {
 85 
 86             e.printStackTrace();
 87             JOptionPane.showMessageDialog(null, "对数据库更改无法应用");
 88 
 89         }
 90         return 0;
 91     }
 92     public static void closeConnect() {
 93         try {
 94             rs.close();
 95         } catch (SQLException e) {
 96             e.printStackTrace();
 97             JOptionPane.showMessageDialog(null, "数据库结果集无法关闭");
 98 
 99         }
100         try {
101             s.close();
102         } catch (SQLException e) {
103 
104             e.printStackTrace();
105             JOptionPane.showMessageDialog(null, "数据库语句无法关闭");
106 
107         }
108         
109         try {
110             conn.close();
111         } catch (SQLException e) {
112 
113             e.printStackTrace();
114             JOptionPane.showMessageDialog(null, "与数据库的连接无法关闭");
115         }
116 /*
117         try { // perform a clean shutdown
118             DriverManager.getConnection("jdbc:derby:;shutdown=true");
119 
120         } catch (SQLException se) {
121 
122             if (((se.getErrorCode() == 50000)
123                     && ("XJ015".equals(se.getSQLState())))) {
124                 // we got the expected exception
125                 System.out.println("Derby shut down normally");
126                 // Note that for single database shutdown, the expected
127                 // SQL state is "08006", and the error code is 45000.
128             } else {
129                 System.err.println("Derby did not shut down normally");
130                 // JOptionPane.showMessageDialog(null, "数据库关闭错误");
131                 se.printStackTrace();
132             }
133         }*/
134     }
135 
136 }