JDBC工具类（ConDB、Dao、MyProperties、MyException、db属性文件）

1.自定义异常类

package com.ownhome.exception;

/**
 * 自定义异常类
 * @author admin
 *
 */
public class MyException extends Exception {
	protected Throwable throwable;
	
	/*构造方法*/
	public MyException(String msg){
		super(msg);
	}
	/*构造方法*/
	public MyException(String msg,Throwable throwable){
		super(msg);
		this.throwable=throwable;
	}
	
	
//	/*得到异常*/
//	public Throwable getEx(){
//		return this.throwable;
//	}
	
	
	/*重写父类方法*/
	@Override
	public void printStackTrace() {
		super.printStackTrace();/*调用父类的方法*/
		if(throwable!=null){
			throwable.printStackTrace();/*输出异常*/
		}
	
	}
	
}

 

 

 

2.db属性文件

 

   driverClass=sun.jdbc.odbc.JdbcOdbcDriver
   url=jdbc:odbc:driver={Sql Server};database=ownHome;server=.
   uid=sa
   pwd=abc

 

3. MyProperties类[单例模式]

package com.ownhome.common;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import com.ownhome.exception.MyException;

/**
 * 用单模式实现从Properties文件里读取连接数据库的参数
 * @author admin
 *
 */
public class MyProperties extends Properties{
	
	
	/*静态属性*/
	private static MyProperties myPro;
	
	/*构造方法*/
	private MyProperties() throws MyException{
		InputStream is=this.getClass().getResourceAsStream("db.properties");
		try {
			this.load(is);
		} catch (IOException e) {
			throw new MyException("读取属性文件错误 !",e);
		}
	}
	
	
	/*公有的静态方法,得到MyProperties对象*/
	public static MyProperties getPro(){
		if(myPro!=null){
			return myPro;
		}
		init();
		return myPro;
		
	}
	
	
	/*实现同步机制,初始化内部属性*/
	private synchronized static void init(){
		if(myPro==null){
			try{
				myPro=new MyProperties();	
			}catch(MyException e){
				e.printStackTrace();
			}
		}
	}
}

 

4.ConDB连接工厂类[工厂模式]

 

package com.ownhome.common;

import java.sql.Connection;
import java.sql.SQLException;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.sql.DataSource;

import com.ownhome.exception.MyException;

/**
 * 连接数据库类
 * @author admin
 *
 */
public class ConDB {
	
//	/*静态方法,属性文件得到连接对象 */
//	public static Connection getCon() throws MyException{
//		
//		MyProperties myPro=MyProperties.getPro();
//		try{
//			Class.forName(myPro.getProperty("driverClass"));
//			return DriverManager.getConnection(myPro.getProperty("url"));
//		}catch(ClassNotFoundException e){
//			throw new MyException("注册驱动错误!",e);
//		}catch(SQLException e){
//			throw new MyException("得到Con连接对象错误",e);
//		}
//	}
	
	/*JNDI方式*/
	public static Connection getCon() throws MyException{
		try {
			Context ic=new InitialContext();
			DataSource source=(DataSource)ic.lookup("java:comp/env/jdbc/ownhome");
			return source.getConnection();
		} catch (NamingException e) {
			throw new MyException("JNDI查找错误@!",e);
		} catch (SQLException e) {
			throw new MyException("得到Connection对象错误!",e);
		}
	}
}

 

5. Dao类工具类

 

package com.ownhome.common;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.jsp.jstl.sql.Result;
import javax.servlet.jsp.jstl.sql.ResultSupport;

import com.ownhome.exception.MyException;

/**
 * Dao类,对数据库进行操作
 * @author admin
 *
 */
public class Dao {
	private Connection con;		
	private String sql;
	private List values;

	public void setCon(Connection con) {
		this.con = con;
	}

	public void setSql(String sql) {
		this.sql = sql;
	}
	/**
	 * 设置sql字符串中?的值
	 * @param values
	 */
	public void setValues(List values) {
		this.values = values;
	}

	/*为sql语句的所有的?设置值*/
	private void setValues(PreparedStatement ps) throws MyException {

		if (values != null) {
			try {
				for (int i = 1; i <= values.size(); i++) {
					ps.setObject(i, values.get(i - 1));
				}
			} catch (SQLException e) {
				throw new MyException("设置sql中参数的值?时出错", e);
			}
		}
	}
	/*决断必需的属性是否为空*/
	private boolean isNull(){
		if(con==null||sql==null||sql.equals("")){
			return true;
		}
		return false;
		
	}
	/**
	 * 查询
	 * @return
	 */
	public Result executeQuery() throws MyException{
		ResultSet rs;
		Result result = null;
		if(isNull()){
			throw new MyException("未初始化Con或Sql属性!");
		}
		try{
			PreparedStatement ps=con.prepareStatement(sql);
			this.setValues(ps);
			rs=ps.executeQuery();
			result=ResultSupport.toResult(rs);
			con.close();
		}catch(SQLException e){
			throw new MyException("用PreparedStatement执行查询时出错",e);
		}catch(MyException e){
			e.printStackTrace();
		}
		return result;
		
	}
	/**
	 * 修改,删除,增加
	 * @return
	 */
	public int executeUpdate() throws MyException{
		int count=0;
		if(isNull()){
			throw new MyException("未初始化Con或Sql属性");
		}
		try{
			PreparedStatement ps=con.prepareStatement(sql);
			this.setValues(ps);
			count = ps.executeUpdate();
			con.close();
		}catch(SQLException e){
			throw new MyException("用PreparedStatement执行更新时出错!",e);
		}catch(MyException e){
			e.printStackTrace();
		}
		return count;
	}
}