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*/@Overridepublic 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;}}