dbconnection.java~9~

一个applet servlet之间通过序列化对象通讯的例子

package espc;

import java.io.*;
import java.sql.*;
import java.util.Properties;

public class DbConnection
{

    Connection conn=null;
    Statement stmt=null;
    ResultSet rset=null;
    //构造方法
    public DbConnection()
    {

    }

    public boolean openConnection()
    {
    //-----------------------------------------------------------------
    //装载数据库的Property文件：其中包括数据库驱动，数据库URL，即用户ID和密码
    //-----------------------------------------------------------------
      Properties prop = new Properties();
        try
        {
            InputStream is = getClass().getResourceAsStream("Db.properties");
            prop.load(is);
            if(is != null)
             is.close();
        }
        catch(IOException e)
        {
            System.out.println("[DbConnection]打开文件时出现错误！");
        }
        String jdbc = prop.getProperty("drivers");
        String url = prop.getProperty("url");
        String user = prop.getProperty("user");
        String password = prop.getProperty("password");
        System.out.println(String.valueOf(String.valueOf((new StringBuffer("jdbc＝[")).append(jdbc).append("]"))));
        System.out.println(String.valueOf(String.valueOf((new StringBuffer("url＝[")).append(url).append("]"))));
        System.out.println(String.valueOf(String.valueOf((new StringBuffer("user＝[")).append(user).append("]"))));
        System.out.println(String.valueOf(String.valueOf((new StringBuffer("password＝[")).append(password).append("]"))));
        try
        {
            Class.forName(jdbc);
            System.out.println("驱动程序加载成功！");
        }
        catch(ClassNotFoundException e)
        {
            System.out.println("JDBC登陆过程中出现错误".concat(String.valueOf(String.valueOf(e.getMessage()))));
            boolean flag = false;
            return flag;
        }
        try
        {
            conn = DriverManager.getConnection(url, user, password);
            System.out.println("数据库连接成功！！");
        }
        catch(SQLException e)
        {
            System.out.println("数据库连接过程中出现错误".concat(String.valueOf(String.valueOf(e.getMessage()))));
            boolean flag1 = false;
            return flag1;
        }
        return true;
    }

    public ResultSet executeQuery(String query)
        throws SQLException
    {
        stmt = conn.createStatement(1004, 1007);
        rset = stmt.executeQuery(query);
        return rset;
    }

    public void executeUpdate(String query)
        throws SQLException
    {
        stmt = conn.createStatement(1004, 1008);
        stmt.executeUpdate(query);
        if(stmt != null)
            stmt.close();
    }

    public void close()
        throws SQLException
    {
        if(conn != null)
            conn.close();
        if(rset != null)
            rset.close();
        if(stmt != null)
            stmt.close();
    }

    protected void finalize()
        throws Throwable
    {
        close();
    }
}