网购系统java版

package com.dangdang.dao.impl; import java.util.*; import java.lang.reflect.Field; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.sql.*; import javax.sql.DataSource; import javax.naming.Context; import javax.naming.InitialContext; import javax.naming.NamingException; import com.dangdang.tools.ObjectFactory; public abstract class BaseDao { private Connection conn = null; private PreparedStatement pstmt = null; private ResultSet rs = null; private final String DRIVER = ObjectFactory.pro.getProperty("DRIVER"); private final String URL = ObjectFactory.pro.getProperty("URL"); private final String DBNAME = ObjectFactory.pro.getProperty("DBNAME"); private final String DBPASS = ObjectFactory.pro.getProperty("DBPASS"); /** * 连接数据库 * @return {@link Connection} */ private Connection getConn(){ Connection conn = null; try { Class.forName(this.DRIVER); conn = DriverManager.getConnection(URL,DBNAME,DBPASS); } catch (ClassNotFoundException e) { e.printStackTrace(); throw new RuntimeException("找不到对应的数据库驱动"); }catch (SQLException e) { e.printStackTrace(); throw new RuntimeException("连接数据库失败"); } return conn; } private Connection getDataSourceConn(){ Connection conn = null; Context ctx; try { ctx = new InitialContext(); DataSource ds = (DataSource)ctx.lookup("java:comp/env/JDBC/liaoJieJie"); conn = ds.getConnection(); } catch (NamingException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); throw new RuntimeException("连接数据库失败"); } return conn; } /** * 释放数据库资源 * @param conn * @param pstmt * @param rs */ private void closeAll(Connection conn,PreparedStatement pstmt,ResultSet rs){ try { if(rs != null){ rs.close(); } } catch (SQLException e) { e.printStackTrace(); throw new RuntimeException("关闭结果集对象失败"); } try { if(pstmt != null){ pstmt.close(); } } catch (SQLException e) { e.printStackTrace(); throw new RuntimeException("关闭预处理语句对象失败"); } try { if(conn != null&&!conn.isClosed()){ conn.close(); } } catch (SQLException e) { e.printStackTrace(); throw new RuntimeException("关闭数据库连接对象失败"); } } /** * 执行增删改 * @param sql * @param param * @return {@link Integer} */ public Integer executeUpdate(String sql,Object[] param){ Integer result = 0; try { conn = this.getConn(); pstmt = conn.prepareStatement(sql); if(param != null){ for (int i = 0; i < param.length; i++) { pstmt.setObject(i+1, param[i]); } } result = pstmt.executeUpdate(); } catch (SQLException e) { e.printStackTrace(); throw new RuntimeException("执行增删改语句失败"+sql); }finally{ this.closeAll(conn, pstmt, null); } return result; } /** * 执行查询 * @param sql * @param param * @return {@link List} */ public List<?> executeQuery(String sql,Object[] param){ List<Object> list = new ArrayList<Object>(); try { conn = this.getConn(); pstmt = conn.prepareStatement(sql); if(param != null){ for (int i = 0; i < param.length; i++) { pstmt.setObject(i+1, param[i]); } } rs = pstmt.executeQuery(); Object oj = null; while(rs.next()){ oj = this.fillDataToExecuteQuery(rs); list.add(oj); } } catch (SQLException e) { e.printStackTrace(); throw new RuntimeException("执行查询语句失败"+sql); }finally{ this.closeAll(conn, pstmt, rs); } return list; } /** * 将结果集中的数据封装成对象 * @param rs * @return {@link Object} */ protected abstract Object fillDataToExecuteQuery(ResultSet rs) throws SQLException; /** * 执行查询 * @param sql * @param param * @return {@link List} */ public List<?> executeQuery(String sql,Object[] param,Class<?> beanClass){ List<Object> list = new ArrayList<Object>(); try { conn = this.getDataSourceConn(); pstmt = conn.prepareStatement(sql); if(param != null){ for (int i = 0; i < param.length; i++) { pstmt.setObject(i+1, param[i]); } } rs = pstmt.executeQuery(); Object oj = null; while(rs.next()){ oj = getJavaBean(rs,beanClass); list.add(oj); } } catch (SQLException e) { e.printStackTrace(); throw new RuntimeException("执行查询语句失败"+sql); }finally{ this.closeAll(conn, pstmt, rs); } return list; } public static Object getJavaBean(ResultSet rs,Class<?> beanClass) { try { // 1、通过beanClass实例化JavaBean对象 Object obj = beanClass.newInstance(); // 2、获得所有属性，循环 Field[] fields = beanClass.getDeclaredFields(); for (Field f : fields) { // 3、获得属性名 String fname = f.getName(); //获得属性类型名 String fTypeName = f.getType().getSimpleName(); if ("Integer".equals(fTypeName)) { fTypeName = "Int"; } // 4、通过属性名生成方法名 String setMethodName = "set" + fname.substring(0, 1).toUpperCase() + fname.substring(1); f.getClass().getSimpleName(); String getMethodName = "get" + fTypeName; // 5、通过方法名和方法参数(属性类型)获得方法对象 Method setm = beanClass.getMethod(setMethodName, f.getType()); Method getm = ResultSet.class.getMethod(getMethodName, String.class); // 6、调用方法，将值通过setXXX方法设置到对应的属性中 setm.invoke(obj, getm.invoke(rs, f.getName())); } return obj; } catch (InstantiationException e) { e.printStackTrace(); throw new RuntimeException("无法实例化当前类的对象"); } catch (IllegalAccessException e) { e.printStackTrace(); throw new RuntimeException("无访问权限"); } catch (SecurityException e) { e.printStackTrace(); throw new RuntimeException("无法通过安全认证"); } catch (NoSuchMethodException e) { e.printStackTrace(); throw new RuntimeException("找不到方法"); } catch (IllegalArgumentException e) { e.printStackTrace(); throw new RuntimeException("错误的参数"); } catch (InvocationTargetException e) { e.getTargetException().printStackTrace(); throw new RuntimeException("对象中没有对应方法"); } } }