SQLHelper类(Java版)， 模仿微软提供的SQLHelper类的功能，真正实现了除SQLHelper类外，外界全部可以无须引用连接数据库的类，并且无须担心数据库的连接与关闭。
SQLHelper类支持数据库字段类型
1) 文本类型
2) 带符号整数类型
3) 双精度浮点数类型
4) 日期类型
注意：如果没有想要的类时，请手动添加到以下方法内
private static void prepareCommand(PreparedStatement pstmt, String[] parms) throws Exception { //代码段}package com.dal;import javax.sql.DataSource;import javax.naming.*;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.util.*;import java.sql.*;public abstract class SQLHelper { /** * 连接数据库 * * @return */ private static Connection getConnect() { try { InitialContext context = new InitialContext(); DataSource ds = (DataSource) context.lookup("java:/MSAccessDS"); return ds.getConnection(); } catch (Exception e) { return null; } } /** * 用于执行语句（eg：insert语句，update语句，delete语句） * * @param String * cmdtext,SQL语句 * @param OracleParameter[] * parms,参数集合 * @return int,SQL语句影响的行数 */ public static int ExecuteNonQuery(String cmdtext, String[] parms) throws Exception { PreparedStatement pstmt = null; Connection conn = null; try { conn = getConnect(); pstmt = conn.prepareStatement(cmdtext); prepareCommand(pstmt, parms); return pstmt.executeUpdate(); } catch (Exception e) { throw new Exception("executeNonQuery方法出错:" + e.getMessage()); } finally { try { if (pstmt != null) pstmt.close(); if (conn != null) conn.close(); } catch (Exception e) { throw new Exception("执行executeNonQuery方法出错:" + e.getMessage()); } } } /** * 用于获取结果集语句（eg：selete * from table） * * @param cmdtext * @param parms * @return ResultSet * @throws Exception */ public static ArrayList ExecuteReader(String cmdtext, String[] parms) throws Exception { PreparedStatement pstmt = null; Connection conn = null; try { conn = getConnect(); pstmt = conn.prepareStatement(cmdtext); prepareCommand(pstmt, parms); ResultSet rs = pstmt.executeQuery(); ArrayList al = new ArrayList(); ResultSetMetaData rsmd = rs.getMetaData(); int column = rsmd.getColumnCount(); while (rs.next()) { Object[] ob = new Object[column]; for (int i = 1; i <= column; i++) { ob[i - 1] = rs.getObject(i); } al.add(ob); } rs.close(); return al; } catch (Exception e) { throw new Exception("executeSqlResultSet方法出错:" + e.getMessage()); } finally { try { if (pstmt != null) pstmt.close(); if (conn != null) conn.close(); } catch (Exception e) { throw new Exception("executeSqlResultSet方法出错:" + e.getMessage()); } } } /** * 用于获取单字段值语句（用名字指定字段） * * @param cmdtext * SQL语句 * @param name * 列名 * @param parms * OracleParameter[] * @return Object * @throws Exception */ public static Object ExecuteScalar(String cmdtext, String name, String[] parms) throws Exception { PreparedStatement pstmt = null; Connection conn = null; ResultSet rs = null; try { conn = getConnect(); pstmt = conn.prepareStatement(cmdtext); prepareCommand(pstmt, parms); rs = pstmt.executeQuery(); if (rs.next()) { return rs.getObject(name); } else { return null; } } catch (Exception e) { throw new Exception("executeSqlObject方法出错:" + e.getMessage()); } finally { try { if (rs != null) rs.close(); if (pstmt != null) pstmt.close(); if (conn != null) conn.close(); } catch (Exception e) { throw new Exception("executeSqlObject方法出错:" + e.getMessage()); } } } /** * 用于获取单字段值语句（用序号指定字段） * * @param cmdtext * SQL语句 * @param index * 列名索引 * @param parms * OracleParameter[] * @return Object * @throws Exception */ public static Object ExecuteScalar(String cmdtext, int index, String[] parms) throws Exception { PreparedStatement pstmt = null; Connection conn = null; ResultSet rs = null; try { conn = getConnect(); pstmt = conn.prepareStatement(cmdtext); prepareCommand(pstmt, parms); rs = pstmt.executeQuery(); if (rs.next()) { return rs.getObject(index); } else { return null; } } catch (Exception e) { throw new Exception("executeSqlObject方法出错:" + e.getMessage()); } finally { try { if (rs != null) rs.close(); if (pstmt != null) pstmt.close(); if (conn != null) conn.close(); } catch (Exception e) { throw new Exception("executeSqlObject方法出错:" + e.getMessage()); } } } /** * @param pstmt * @param cmdtext * @param parms * Object[] * @throws Exception */ private static void prepareCommand(PreparedStatement pstmt, String[] parms) throws Exception { try { if (parms != null) { for (int i = 0; i < parms.length; i++) { try { pstmt.setDate(i + 1, java.sql.Date.valueOf(parms[i])); } catch (Exception e) { try { pstmt .setDouble(i + 1, Double .parseDouble(parms[i])); } catch (Exception e1) { try { pstmt.setInt(i + 1, Integer.parseInt(parms[i])); } catch (Exception e2) { try { pstmt.setString(i + 1, parms[i]); } catch (Exception e3) { System.out .print("SQLHelper-PrepareCommand Err1:" + e3); } } } } } } } catch (Exception e1) { System.out.print("SQLHelper-PrepareCommand Err2:" + e1); } }}