crawler.java

Grid based Search Engine

	           }
	     else if(count >= 4)
	           {
        		con4=DriverManager.getConnection(connectionAddress4,"","");
        		stmt=con4.createStatement();

        		stmt.executeUpdate(insertString);
        		stmt.close();
        		con4.close();
	           }

        	}
        catch(SQLException ex)
        	{
        		System.err.println("SQLException2: "+ex.getMessage());
            }

    }


public void delete(String urlAddress)
   		{

		String deleteString;
		deleteString="delete from CRAWLTABLE where URLADDRESS='"+urlAddress+"'";
        try
        	{
        		Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        	}
        catch(java.lang.ClassNotFoundException e)
        	{
        		System.err.print("ClassNotFoundException: ");
        		System.err.println(e.getMessage());
            }

        try
        	{
	       if(count == 1)
	           {
        		con1=DriverManager.getConnection(connectionAddress1,"", "");
        		stmt=con1.createStatement();
        		stmt.executeUpdate(deleteString);
        		stmt.close();
        		con1.close();
	          }
	       if(count == 2)
	           {
        		con2=DriverManager.getConnection(connectionAddress2,"", "");
        		stmt=con2.createStatement();
        		stmt.executeUpdate(deleteString);
        		stmt.close();
        		con2.close();
	          }
	       if(count == 3)
	           {
        		con3=DriverManager.getConnection(connectionAddress3,"", "");
        		stmt=con3.createStatement();
        		stmt.executeUpdate(deleteString);
        		stmt.close();
        		con3.close();
	          }
	       if(count >= 4)
	           {
        		con4=DriverManager.getConnection(connectionAddress4,"", "");
        		stmt=con4.createStatement();
        		stmt.executeUpdate(deleteString);
        		stmt.close();
        		con4.close();
	          }

        	}
        catch(SQLException ex)
        	{
        		System.err.println("SQLException2: "+ex.getMessage());
            }

    }




    public boolean isRecordFalse()
    	{
    	boolean flag=false;
    	String query;
		query=" select URLADDRESS from CRAWLTABLE "+
		"where ISCRAWLED='f'";

        try
        	{
        		Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        	}
        catch(java.lang.ClassNotFoundException e)
        	{
        		System.err.print("ClassNotFoundException: ");
        		System.err.println(e.getMessage());
            }

        try
        	{
	      if(count == 1)
	          {
        		con1=DriverManager.getConnection(connectionAddress1,"", "");
        		stmt=con1.createStatement();
                rs=stmt.executeQuery(query);
        		if(rs.next()==true)
        		{
        			flag= true;
        		   	//System.out.println(flag);
        		}
        		else
        		{
        		   	flag= false;
        		 	

        		}
        		stmt.close();
        		con1.close();
	       }

	      if(count == 2)
	          {
        		con2=DriverManager.getConnection(connectionAddress2,"", "");
        		stmt=con2.createStatement();
                rs=stmt.executeQuery(query);
        		if(rs.next()==true)
        		{
        			flag= true;
        		   	//System.out.println(flag);
        		}
        		else
        		{
        		   	flag= false;
        		 	

        		}
        		stmt.close();
        		con2.close();
	       }
	      if(count == 3)
	          {
        		con3=DriverManager.getConnection(connectionAddress3,"", "");
        		stmt=con3.createStatement();
                rs=stmt.executeQuery(query);
        		if(rs.next()==true)
        		{
        			flag= true;
        		   	//System.out.println(flag);
        		}
        		else
        		{
        		   	flag= false;
        		 	

        		}
        		stmt.close();
        		con3.close();
	       }
	      if(count >= 4)
	          {
        		con4=DriverManager.getConnection(connectionAddress4,"", "");
        		stmt=con4.createStatement();
                rs=stmt.executeQuery(query);
        		if(rs.next()==true)
        		{
        			flag= true;
        		   	//System.out.println(flag);
        		}
        		else
        		{
        		   	flag= false;
        		 	

        		}
        		stmt.close();
        		con4.close();
	       }


        	}
        catch(SQLException ex)
        	{
        		System.err.println( "SQLException3: "+ex.getMessage());
            }
   		return flag;


        }


    
    
    public String retrieveFirst()
    	{
    	
    	String query,s="";
		query=" select URLADDRESS from CRAWLTABLE where "+
		"ISCRAWLED='f' order by SERIAL";

        try
        	{
        		Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        	}
        catch(java.lang.ClassNotFoundException e)
        	{
        		System.err.print("ClassNotFoundException: ");
        		System.err.println(e.getMessage());
        		return null;
            }

        try
        	{
	      if(count == 1)
	          {
        		con1=DriverManager.getConnection(connectionAddress1,"", "");
        		stmt=con1.createStatement();
                rs=stmt.executeQuery(query);
        		
        		if(rs.next()==true)
        		{
        		s=rs.getString("URLADDRESS");
        		}
        		stmt.close();
        		con1.close();

                        }

	      if(count == 2)
	          {
        		con2=DriverManager.getConnection(connectionAddress2,"", "");
        		stmt=con2.createStatement();
                rs=stmt.executeQuery(query);
        		
        		if(rs.next()==true)
        		{
        		s=rs.getString("URLADDRESS");
        		}
        		stmt.close();
        		con2.close();

                        }

	      if(count == 3)
	          {
        		con3=DriverManager.getConnection(connectionAddress3,"", "");
        		stmt=con3.createStatement();
                rs=stmt.executeQuery(query);
        		
        		if(rs.next()==true)
        		{
        		s=rs.getString("URLADDRESS");
        		}
        		stmt.close();
        		con3.close();

                        }

	      if(count >= 4)
	          {
        		con4=DriverManager.getConnection(connectionAddress4,"", "");
        		stmt=con4.createStatement();
                rs=stmt.executeQuery(query);
        		
        		if(rs.next()==true)
        		{
        		s=rs.getString("URLADDRESS");
        		}
        		stmt.close();
        		con4.close();

                        }


        	}
        catch(SQLException ex)
        	{
        		System.err.println( "SQLException3: "+ex.getMessage());
        		return null;
            }
   		
		return s;

        }


    
    
    public boolean contains(String strURL)
    	{
    	boolean flag=false;
    	String query;
		query=" select URLADDRESS from CRAWLTABLE "+
		"where URLADDRESS='"+strURL+"'";

        try
        	{
        		Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        	}
        catch(java.lang.ClassNotFoundException e)
        	{
        		System.err.print("ClassNotFoundException: ");
        		System.err.println(e.getMessage());
            }

        try
        	{
	     if(count == 1)
	         {
        		con1=DriverManager.getConnection(connectionAddress1,"", "");
        		stmt=con1.createStatement();
                rs=stmt.executeQuery(query);
        		if(rs.next()==true)
        		{
        			flag= true;
        		   	//System.out.println(flag);
        		}
        		else
        		{
        		   	flag= false;
        		 	//System.out.println(flag);

        		}
        		stmt.close();
        		con1.close();
	        }

	     if(count == 2)
	         {
        		con2=DriverManager.getConnection(connectionAddress2,"", "");
        		stmt=con2.createStatement();
                rs=stmt.executeQuery(query);
        		if(rs.next()==true)
        		{
        			flag= true;
        		   	//System.out.println(flag);
        		}
        		else
        		{
        		   	flag= false;
        		 	//System.out.println(flag);

        		}
        		stmt.close();
        		con2.close();
	        }

	     if(count == 3)
	         {
        		con3=DriverManager.getConnection(connectionAddress3,"", "");
        		stmt=con3.createStatement();
                rs=stmt.executeQuery(query);
        		if(rs.next()==true)
        		{
        			flag= true;
        		   	//System.out.println(flag);
        		}
        		else
        		{
        		   	flag= false;
        		 	//System.out.println(flag);

        		}
        		stmt.close();
        		con3.close();
	        }

	     if(count >=4)
	         {
        		con4=DriverManager.getConnection(connectionAddress4,"", "");
        		stmt=con4.createStatement();
                rs=stmt.executeQuery(query);
        		if(rs.next()==true)
        		{
        			flag= true;
        		   	//System.out.println(flag);
        		}
        		else
        		{
        		   	flag= false;
        		 	//System.out.println(flag);

        		}
        		stmt.close();
        		con4.close();
	        }


        	}
        catch(SQLException ex)
        	{
        		System.err.println( "SQLException3: "+ex.getMessage());
            }
   		return flag;


        }


    
    
       public void updateRecord(String urlAddress)
       {

		String updateString;
		updateString="update CRAWLTABLE"+
		" set ISCRAWLED='t'" + " where URLADDRESS='"+urlAddress+"'";


        try
        	{
        		Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
        	}
        catch(java.lang.ClassNotFoundException e)
        	{
        		System.err.print("ClassNotFoundException: ");
        		System.err.println(e.getMessage());
            }

        try
        	{
	     if(count == 1)
	        {
        		con1=DriverManager.getConnection(connectionAddress1,"", "");
        		stmt=con1.createStatement(); 
        		stmt.executeUpdate(updateString);
        		stmt.close();
        		con1.close();
	      }
	     if(count == 2)
	        {
        		con2=DriverManager.getConnection(connectionAddress2,"", "");
        		stmt=con2.createStatement(); 
        		stmt.executeUpdate(updateString);
        		stmt.close();
        		con2.close();
	      }
	     if(count == 3)
	        {
        		con3=DriverManager.getConnection(connectionAddress3,"", "");
        		stmt=con3.createStatement(); 
        		stmt.executeUpdate(updateString);
        		stmt.close();
        		con3.close();
	      }
	     if(count >= 4)
	        {
        		con4=DriverManager.getConnection(connectionAddress4,"", "");
        		stmt=con4.createStatement(); 
        		stmt.executeUpdate(updateString);
        		stmt.close();
        		con4.close();
	      }

        	}
        catch(SQLException ex)
        	{
        		System.err.println("SQLException4: "+ex.getMessage());
            }

      }
}