SqlHelper操纵数据库工具类

该工具类是SqlHelper的基础版本，将整个类做成静态类，这样可能很难应付高并发的数据库操作，不过这个问题是能够解决的，通过创建SqlHelper对象，将成员变量，成员方法的static去掉，将获取连接这个操作分离出去，做成一个类，每次获取连接时，获取那个类的对象。这样就在一定程度上解决并发的问题。

属性文件dbInfo.properties，放在Java项目根目录下，想放在src目录下要用类加载器

#oracle 配置
url=jdbc:oracle:thin:@127.0.0.1:1521:SWITCH
user=scott
password=123456
driver=oracle.jdbc.driver.OracleDriver

1.0版 SqlHelper.java

提供以下功能：

callPro1(String sql, String[] parameters) 调用存储过程，无返回值

callPro2(String sql, String[] inParameters,Integer[] outParameters) 调用存储过程，有返回值

ResultSet executeQuery(String sql, String[] parameters) 简单的Select操作

ArrayList executeQuery2(String sql, String[] parameters) 二次封装的Select操作，稍复杂

executeUpdate(String[] sql, String[][] parameters) 考虑事务的update/delete/insert(DML)方法

executeUpdate(String sql, String[] parameters) 单次的update/delete/insert(DML)方法

package com.jdbc;
import java.sql.Statement;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Properties;/*** * @author Switch* @function 提供数据库访问方法* */
public class SqlHelper {// 定义需要的变量private static Connection ct = null;private static PreparedStatement ps = null;private static ResultSet rs = null;private static CallableStatement cs = null;// 连接数据库参数private static String url = "";private static String user = "";private static String password = "";private static String driver = "";private static Properties pp = null;private static FileInputStream fis = null;// 静态代码块加载驱动static {try {// 从dbInfo.properties文件中读取配置信息pp = new Properties();try {fis = new FileInputStream("dbInfo.properties");} catch (FileNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();}try {pp.load(fis);url = pp.getProperty("url");user = pp.getProperty("user");password = pp.getProperty("password");driver = pp.getProperty("driver");} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}Class.forName(driver);} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} finally {// 关闭资源try {fis.close();} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}fis = null;}}// 得到连接public static Connection getConnection() {try {ct = DriverManager.getConnection(url, user, password);} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return ct;}// 获得PreparedStatementpublic static PreparedStatement getPreparedStatement() {return ps;}// 得到Connectionpublic static Connection getCt() {return ct;}// 得到PreparedStatementpublic static PreparedStatement getPs() {return ps;}// 得到CallableStatementpublic static CallableStatement getCs() {return cs;}// 得到ResultSetpublic static ResultSet getRs() {return rs;}// 调用存储过程，无返回值// sql {call 过程名(?,?,?)}public static void callPro1(String sql, String[] parameters) {try {ct = getConnection();cs = ct.prepareCall(sql);// ?赋值if (parameters != null && !parameters.equals("")) {for (int i = 0; i < parameters.length; i++) {cs.setObject(i + 1, parameters[i]);}}cs.execute();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();throw new RuntimeException(e.getMessage());} finally {close(rs, cs, ct);}}// 调用存储过程，有返回值public static CallableStatement callPro2(String sql, String[] inParameters,Integer[] outParameters) {try {ct = getConnection();cs = ct.prepareCall(sql);// 输入参数if (inParameters != null && !inParameters.equals("")) {for (int i = 0; i < inParameters.length; i++) {cs.setObject(i + 1, inParameters[i]);}}// 输出参数if (outParameters != null) {for (int i = 0; i < outParameters.length; i++) {cs.registerOutParameter(inParameters.length + i + 1,outParameters[i]);}}cs.execute();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();throw new RuntimeException(e.getMessage());} finally {}return cs;}// select方法public static ResultSet executeQuery(String sql, String[] parameters) {try {ct = getConnection();ps = ct.prepareStatement(sql);if (parameters != null && !parameters.equals("")) {for (int i = 0; i < parameters.length; i++) {ps.setString(i + 1, parameters[i]);}}rs = ps.executeQuery();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();throw new RuntimeException(e.getMessage());}return rs;}// select方法2(更安全)----规则：哪里使用资源，哪里关闭资源public static ArrayList executeQuery2(String sql, String[] parameters) {ArrayList result = null;try {ct = getConnection();ps = ct.prepareStatement(sql);if (parameters != null && !parameters.equals("")) {for (int i = 0; i < parameters.length; i++) {ps.setString(i + 1, parameters[i]);}}rs = ps.executeQuery();// 获取结果原始信息ResultSetMetaData resultSetMetaData = rs.getMetaData();int column = resultSetMetaData.getColumnCount();result = new ArrayList();// 一行数据while (rs.next()) {// 对象数组，表示一行数据Object[] ob = new Object[column];for (int i = 1; i <= column; i++) {// 一项数据ob[i - 1] = rs.getObject(i);}result.add(ob);}} catch (Exception e) {e.printStackTrace();throw new RuntimeException(e.getMessage());} finally {SqlHelper.close(rs, ps, ct);}return result;}// 考虑事务的update/delete/insert(DML)方法public static void executeUpdate(String[] sql, String[][] parameters) {try {// 获得连接ct = getConnection();// 将自动提交设置为falsect.setAutoCommit(false);// 设置事务级别为Serializablect.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE);// 用户传入的可能是多个SQL语句for (int i = 0; i < sql.length; i++) {if (parameters[i] != null && !parameters[i].equals("")) {ps = ct.prepareStatement(sql[i]);for (int j = 0; j < parameters[i].length; j++) {// 给?赋值ps.setString(j + 1, parameters[i][j]);}}// 执行操作ps.executeUpdate();}// 提交ct.commit();} catch (Exception e) {// TODO: handle exception// 回滚try {ct.rollback();} catch (SQLException e1) {// TODO Auto-generated catch blocke1.printStackTrace();}e.printStackTrace();throw new RuntimeException(e.getMessage());} finally {close(rs, ps, ct);}}// 不考虑事务的update/delete/insert(DML)方法public static void executeUpdate(String sql, String[] parameters) {// 创建pstry {ct = getConnection();ps = ct.prepareStatement(sql);if (parameters != null && !parameters.equals("")) {// 给?赋值for (int i = 0; i < parameters.length; i++) {ps.setString(i + 1, parameters[i]);}}// 执行操作ps.executeUpdate();} catch (SQLException e) {// TODO Auto-generated catch block// 开发阶段使用e.printStackTrace();// 抛出运行异常,可以给调用该方法的方法一个选择// 可以处理也可以放弃处理throw new RuntimeException(e.getMessage());} finally {close(rs, ps, ct);}}// 关闭资源的方法public static void close(ResultSet rs, Statement ps, Connection ct) {// 先开后闭if (rs != null) {try {rs.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}// 使用垃圾回收机制回收rs = null;}if (ps != null) {try {ps.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}// 使用垃圾回收机制回收ps = null;}if (ct != null) {try {ct.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}// 使用垃圾回收机制回收ct = null;}}
}