小米商城系统（适合毕业设计）.zip

package com.oracle.util; import com.alibaba.druid.pool.DruidDataSource; import java.io.InputStream; import java.sql.*; import java.util.List; import java.util.Properties; public class DruidDBUtil { //声明druid连接池对象 private static DruidDataSource dataSource = null; //访问数据库的小帮手 private static String url = null; private static String username = null; private static String password = null; /** * 初始连接数 **/ private static int initialSize; /** * 最大活动连接数 **/ private static int maxActive; /** * 最小闲置连接数 **/ private static int minIdle; /** * 连接耗尽时最大等待获取连接时间 **/ private static long maxWait; //保证线程安全的数据库访问，一个线程只绑定一个链接对象，多次访问时同一个连接对象 private static ThreadLocal<Connection> tl = new ThreadLocal<Connection>(); private DruidDBUtil() { } static { initPool(); } private static void initPool() { try { Properties pro = new Properties(); InputStream in = com.oracle.util.DruidDBUtil.class.getClassLoader().getResourceAsStream("druid.properties"); pro.load(in); //读取属性文档配置信息 String driverClassName = pro.getProperty("driverClassName"); Class.forName(driverClassName); url = pro.getProperty("url"); username = pro.getProperty("username"); password = pro.getProperty("password"); initialSize = Integer.parseInt(pro.getProperty("initialSize")); maxActive = Integer.parseInt(pro.getProperty("maxActive")); maxWait = Integer.parseInt(pro.getProperty("maxWait")); minIdle = Integer.parseInt(pro.getProperty("minIdle")); //创建druid数据源 dataSource = new DruidDataSource(); dataSource.setUrl(url); dataSource.setUsername(username); dataSource.setPassword(password); //设置连接池中初始连接数 dataSource.setInitialSize(initialSize); //设置最大连接数 dataSource.setMaxActive(maxActive); //设置最小的闲置链接数 dataSource.setMinIdle(minIdle); //设置最大的等待时间(等待获取链接的时间) dataSource.setMaxWait(maxWait); } catch (Exception ex) { ex.printStackTrace(); } } //由于使用了数据库连接池，我们不采用单例模式 public static Connection getConnection() throws Exception { // 先从当前线程上获得链接 Connection conn = tl.get(); try { if (conn == null || conn.isClosed()) { //从连接池中获取连接对象 conn = dataSource.getConnection(); // 把连接绑定到当前线程上 tl.set(conn); } } catch (SQLException e) { e.printStackTrace(); } return conn; } //关闭所有数据库访问对象 public static void closeAll() { try { if (com.oracle.util.DruidDBUtil.getConnection() != null && !com.oracle.util.DruidDBUtil.getConnection().isClosed()) { com.oracle.util.DruidDBUtil.getConnection().close(); } } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } // 所有的增删改的方法 public static int executeUpdate(String sql, List list) throws Exception { //添加第二个参数的意义是为了获得新增记录的主键。 PreparedStatement pstm = getConnection().prepareStatement(sql, Statement.RETURN_GENERATED_KEYS); if (list != null) { for (int i = 0; i < list.size(); i++) { pstm.setObject(i + 1, list.get(i)); } } return pstm.executeUpdate(); } // 执行更新语句返回自增主键值。 public static Long executeUpdateWithReturnId(String sql, List list) throws Exception { //添加第二个参数的意义是为了获得新增记录的主键。 PreparedStatement pstm = getConnection().prepareStatement(sql, Statement.RETURN_GENERATED_KEYS); if (list != null) { for (int i = 0; i < list.size(); i++) { pstm.setObject(i + 1, list.get(i)); } } pstm.executeUpdate(); ResultSet rs = pstm.getGeneratedKeys(); Long id = -1L; //注意：这里必须把游标指向第一条记录。 if(rs.next()){ id = rs.getLong(1); } return id; } //执行批处理 public static int[] executeBatch(String sql, List<List> list) throws Exception { //添加第二个参数的意义是为了获得新增记录的主键。 PreparedStatement pstm = getConnection().prepareStatement(sql, Statement.RETURN_GENERATED_KEYS); if (list != null) { for (int i = 0; i < list.size(); i++) { for (int j = 0; j < list.get(i).size(); j++) { pstm.setObject(j + 1, list.get(i).get(j)); } pstm.addBatch(); } } return pstm.executeBatch(); } // 所有的查询的方法 public static ResultSet executeQuery(String sql, List list) throws Exception { //第二个参数的意思，执行更新语句后可以获得主键 PreparedStatement pstm = getConnection().prepareStatement(sql); if (list != null) { for (int i = 0; i < list.size(); i++) { pstm.setObject(i + 1, list.get(i)); } } return pstm.executeQuery(); } public static void startTransaction() { Connection conn = null; try { conn = getConnection(); conn.setAutoCommit(false); } catch (Exception e) { e.printStackTrace(); } } public static void commit() { Connection conn = null; try { conn = getConnection(); conn.commit(); } catch (Exception e) { e.printStackTrace(); } } public static void rollback() { Connection conn = null; try { conn = getConnection(); conn.rollback(); } catch (Exception e) { e.printStackTrace(); } } public static void release() { Connection conn = null; try { conn = getConnection(); conn.close(); tl.remove();// 与线程池有关，解除关系 } catch (Exception e) { e.printStackTrace(); } } public static void endTransaction() { Connection conn = null; try { conn = getConnection(); conn.setAutoCommit(true); } catch (Exception e) { e.printStackTrace(); } } public static void main(String[] args) throws Exception { Connection conn = DruidDBUtil.getConnection(); if (conn != null) { System.out.println("MySQL连接成功！"); } else { System.out.println("MySQL连接失败！"); } } }