java swing的电子商务系统【源码+数据库】

package util; import java.lang.reflect.Field; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.SQLException; import java.sql.Statement; import java.sql.Timestamp; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.List; import java.util.Map; import org.apache.log4j.Logger; import entity.Page; public class DBUtil { private static Logger logger = Logger.getLogger(DBUtil.class); private static ThreadLocal<Connection> tl = new ThreadLocal<Connection>(); public static Connection getConnection() throws Exception { try { Connection conn = tl.get(); if (conn == null) { // conn为空就创建一个新的conn conn = DBDataSource.getConnectionC3P0(); // 将conn存入到当前线程中? tl.set(conn); } return conn; } catch (Exception e) { logger.info(e.getMessage()); throw new Exception(e); } } /** * 获取单条记录，并以对象形式返回，sql中没有占位符参数 select * from table where id = 1 * * @param sql * @param cls * @return * @throws Exception */ public static <T> T getObject(String sql, Class<T> cls) throws Exception { return getObject(sql, null, cls); } /** * 获取单条记录，并以对象形式返回，sql中含有占位符参数 select * from table where id = ? * * @param sql * @param paras * @param cls * @return * @throws Exception */ public static <T> T getObject(String sql, List<Object> paramList, Class<T> cls) throws Exception { Connection conn = getConnection(); PreparedStatement pst = null; ResultSet rs = null; T singleObject = null; int index = 1; try { pst = conn.prepareStatement(sql); if (pst == null) { return null; } setPreparedStatementParamByType(pst,paramList); rs = pst.executeQuery(); ResultSetMetaData rsmd = rs.getMetaData(); int columnCount = rsmd.getColumnCount(); while (rs.next()) { singleObject = cls.newInstance(); for (int i = 0; i < columnCount; i++) { // 获取的是原始名 // String columnName = rsmd.getColumnName(i + 1); // 获取的是别名 String columnName = rsmd.getColumnLabel(i + 1); Object columnValue = rs.getObject(columnName); // 如果数据库字段带有下划线，比如user_id,则需要转为userId; columnName = StringUtil.lineToHump(columnName); Field field = cls.getDeclaredField(columnName); field.setAccessible(true); field.set(singleObject, columnValue); } } } catch (Exception e) { // TODO Auto-generated catch block logger.info(e.getMessage()); throw new Exception(e); } finally { close(conn, pst); } return singleObject; } /** * 获取单条记录，并以Map形式返回，sql中含有占位符参数 * * @param sql：查询语句 * @return * @throws Exception */ public static Map<String, Object> getObjectMap(String sql) throws Exception { return getObjectMap(sql, null); } /** * 获取单条记录，并以Map形式返回，sql中含有占位符参数 * * @param sql：查询语句 * @param paramList：参数 * @return * @throws Exception */ public static Map<String, Object> getObjectMap(String sql, List<Object> paramList) throws Exception { if (sql == null || sql.trim().equals("")) { logger.info("parameter is valid!"); return null; } Connection conn = null; PreparedStatement pst = null; ResultSet rs = null; Map map = new HashMap<String, Object>(); try { conn = getConnection(); pst = conn.prepareStatement(sql); if (pst == null) { return null; } setPreparedStatementParamByType(pst, paramList); rs = pst.executeQuery(); List list = getQueryMapList(rs); if (list.isEmpty()) { return null; } map = (HashMap) list.get(0); } catch (Exception e) { logger.info(e.getMessage()); throw new Exception(e); } finally { close(conn, pst, rs); } return map; } /** * 查询记录，返回对象列表，sql中没有占位符参数 select * table where name like '%张三%'; * * @param sql * 查询语句 * @param cls * 返回对象的类型 * @return * @throws Exception */ public static <T> List<T> getQueryList(String sql, Class<T> cls) throws Exception { return getQueryList(sql, null, cls); } /** * 查询记录，返回对象列表，sql中含有占位符参数 select* from table where name like '%?%' * * @param sql * 查询语句 * @param paras * 查询参数 * @param cls * 返回对象的类型 * @return * @throws Exception */ public static <T> List<T> getQueryList(String sql, List<Object> paramList, Class<T> cls) throws Exception { Connection conn = getConnection(); PreparedStatement pst = null; ResultSet rs = null; T singleObject = null; int index = 1; List<T> list = new ArrayList<T>(); try { pst = conn.prepareStatement(sql); if (pst == null) { return null; } setPreparedStatementParamByType(pst, paramList); rs = pst.executeQuery(); ResultSetMetaData rsmd = rs.getMetaData(); int columnCount = rsmd.getColumnCount(); while (rs.next()) { singleObject = cls.newInstance(); for (int i = 0; i < columnCount; i++) { // 获取的是原始名 // String columnName = rsmd.getColumnName(i + 1); // 获取的是别名 String columnName = rsmd.getColumnLabel(i + 1); Object columnValue = rs.getObject(columnName); // 如果数据库字段带有下划线，比如user_id,则需要转为userId; columnName = StringUtil.lineToHump(columnName); Field field = cls.getDeclaredField(columnName); field.setAccessible(true); field.set(singleObject, columnValue); } list.add(singleObject); } } catch (Exception e) { logger.info(e.getMessage()); throw new Exception(e); } finally { close(conn, pst, rs); } return list; } /** * 查询记录，返回Map数据列表，sql中无占位符参数 select * table where name like '%张三%'; * * @param sql：查询语句 * @return */ public static List<Map<String, Object>> getQueryMapList(String sql) throws Exception { return getQueryMapList(sql, null); } /** * 查询记录，返回Map数据列表，sql有占位符参数 select * table where name like '%?%'; * * @param sql�? * 查询 * @param paramList�? * 占位符参数 * @return */ public static List<Map<String, Object>> getQueryMapList(String sql, List<Object> paramList) throws Exception { if (sql == null || sql.trim().equals("")) { logger.info("parameter is valid!"); return null; } Connection conn = null; PreparedStatement pst = null; ResultSet rs = null; List<Map<String, Object>> queryList = null; try { conn = getConnection(); pst = conn.prepareStatement(sql); if (pst == null) { return null; } setPreparedStatementParamByType(pst, paramList); rs = pst.executeQuery(); queryList = getQueryMapList(rs); } catch (RuntimeException e) { logger.info(e.getMessage()); throw new Exception(e); } finally { close(conn, pst, rs); } return queryList; } /** * 分页查询，分页list为对象集合 * * @param sql 查询语句 * @param params 查询条件参数 * @param page 分页信息 * @return * @throws Exception */ public static <T> Page getQueryPage(String sql, List<Object> paramList, Page page, Class<T> cls) throws Exception { int totalPages = 0; //页数 Integer rows = 0;//数据条数 //分页工具类 List<T> list = null