keygenerator.java

功能是公安和学校的管理系统,用struts+hibernate+spring等匡架组成,在eclepse就能编译

package com.db;

import java.io.PrintStream;
import java.sql.*;
import java.util.HashMap;
import com.db.DBUtils;

public class KeyGenerator
{

    private static KeyGenerator keygenerator = new KeyGenerator();
    private static int ikey = 1;
    private HashMap myhashmap;

    public KeyGenerator()
    {
        myhashmap = new HashMap(10);
    }

    public static KeyGenerator getInstance()
    {
        return keygenerator;
    }

    public synchronized int getNextKey(String keyName)
        throws KeyGenException
    {
        KeyInfo keyInfo = null;
        if(myhashmap.containsKey(keyName))
            keyInfo = (KeyInfo)myhashmap.get(keyName);
        else
            keyInfo = new KeyInfo(ikey, keyName);
        return keyInfo.getNextKey();
    }

    public boolean isExisteKeyName(String keyName)
    {
        boolean flag = false;
        Connection conn=null;
        PreparedStatement stmt=null;
        ResultSet rs=null;
        try
        {
            conn=DBUtils.getConnection();
            String sql ="select * from XT_ZDZZ where seq_name = ?";
            stmt = conn.prepareStatement(sql);
            stmt.setString(1,keyName);
            rs = stmt.executeQuery();
            if(rs.next())
                flag = true;
        }
        catch(Exception exception) { }
        finally
        {
          DBUtils.closeResultSet(rs);
          DBUtils.closeStatement(stmt);
          DBUtils.closeConnection(conn);
        }
        return flag;
    }

    public boolean createKeyName(String keyName)
    {
        return createKeyName(keyName, 0);
    }

    public boolean createKeyName(String keyName, int curr_value)
    {
        boolean flag = false;
        Connection conn=null;
        PreparedStatement stmt=null;
        try
        {
            conn=DBUtils.getConnection();
            if(curr_value < 0)
                curr_value = 0;
            stmt = conn.prepareStatement("insert into XT_ZDZZ(seq_name, curr_value) values(?,?)");
            stmt.setString(1,keyName);
            stmt.setInt(2,curr_value);
            if(stmt.executeUpdate() == 1)
                flag = true;
        }
        catch(Exception exception) { }
        finally
        {
           DBUtils.closeStatement(stmt);
           DBUtils.closeConnection(conn);
        }
        return flag;
    }
}