数据库操作类

package 数据库操作类;


	/* * Db.java
	Created on 2007年8月20日, 上午 8:37
	*/
	import java.io.*;
	import java.sql.*;
	import java.util.Properties;
	public class DB {
	    private String driver;
	    private String url;
	    private String user;
	    private String password;
	    private Connection conn;
	    private Statement stm;
	    private ResultSet rs;
	    public DB(){
	        this("DBConf.properties");
	    }
	    public DB(String conf) {
	        loadProperties(conf);
	        setConn();
	    }
	    public Connection getConn(){
	        return this.conn;
	    }
	  //handle the properties file to get the informations for connection
	    private void loadProperties(String conf){
	        Properties props = new Properties();
	        try {
	            props.load(new FileInputStream(conf));
	        } catch (FileNotFoundException e) {
	            e.printStackTrace();
	        } catch (IOException e) {
	            e.printStackTrace();
	        }
	        this.driver = props.getProperty("driver");
	        this.url = props.getProperty("url");
	        this.user = props.getProperty("user");
	        this.password = props.getProperty("password");
	    }
	    //implement the Connection
	    private void setConn(){
	        try {
	            Class.forName(driver);
	            this.conn = DriverManager.getConnection(url,user,password);
	        } catch(ClassNotFoundException classnotfoundexception) {
	              classnotfoundexception.printStackTrace();
	            System.err.println("db: " + classnotfoundexception.getMessage());
	        } catch(SQLException sqlexception) {
	            System.err.println("db.getconn(): " + sqlexception.getMessage());
	        }
	    }
	       public void doInsert(String sql) {
	        try {
	            Statement statement = conn.createStatement();
	            int i = stm.executeUpdate(sql);
	        } catch(SQLException sqlexception) {
	            System.err.println("db.executeInset:" + sqlexception.getMessage());
	        }
	    }
	    public void doDelete(String sql) {
	        try {
	            stm = conn.createStatement();
	            int i = stm.executeUpdate(sql);
	        } catch(SQLException sqlexception) {
	            System.err.println("db.executeDelete:" + sqlexception.getMessage());
	        }
	    }
	    public void doUpdate(String sql) {
	        try {
	            stm = conn.createStatement();
	            int i = stm.executeUpdate(sql);
	        } catch(SQLException sqlexception) {
	            System.err.println("db.executeUpdate:" + sqlexception.getMessage());
	        }
	    }
	    
	    public ResultSet doSelect(String sql) {
	        try {
	            stm = conn.createStatement(java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE,java.sql.ResultSet.CONCUR_READ_ONLY);
	            rs = stm.executeQuery(sql);
	        } catch(SQLException sqlexception) {
	            System.err.println("db.executeQuery: " + sqlexception.getMessage());
	        }
	        return rs;
	    }
	    public static void main(String[] args){
	        try{
	            DB db = new DB();
	            Connection conn = db.getConn();
	            if(conn != null && !conn.isClosed()) {
	                System.out.println("連結成功");
	                ResultSet rs = db.doSelect("select * from content");
	                while(rs.next()){
	                    System.out.println(rs.getString(1)+":"+rs.getString(2)+":"+rs.getString(3));
	                  }
	                rs.close();
	                conn.close();
	            }
	        }catch(SQLException e) {
	            e.printStackTrace();
	        }
	    }  
	}