超市订单管理系统smbms.zip

package com.sqq.dao;

import com.sun.org.apache.xpath.internal.operations.Bool;

import java.io.IOException;
import java.io.InputStream;
import java.sql.*;
import java.util.Properties;

//操作数据库的公共类
public class baseDao {
    private static String driver;
    private static String url;
    private static String username;
    private static String password;

    //静态代码块，类加载的时候就初始化了
    static {
        Properties properties = new Properties（）;
        //通过类加载器读取对应的资源
        InputStream is = baseDao.class.getClassLoader（）.getResourceAsStream（“db.properties“）;

        try {
            properties.load（is）;
        } catch （IOException e） {
            e.printStackTrace（）;
        }

        driver = properties.getProperty（“driver“）;
        url = properties.getProperty（“url“）;
        username = properties.getProperty（“username“）;
        password = properties.getProperty（“password“）;

    }

    //获取数据库的连接
    public static Connection getConnection（）{
        Connection connection = null;
        try {
            Class.forName（driver）;
            connection= DriverManager.getConnection（urlusernamepassword）;
        } catch （Exception e） {
            e.printStackTrace（）;
        }
        return connection;
    }

    //编写查询公共类
    public static ResultSet execute（Connection connection PreparedStatement preparedStatement   ResultSet resultSet String sql object[] params） throws SQLException {
        //预编译的sql，在后面直接执行就可以了
        preparedStatement = connection.prepareStatement（sql）;
        for （int i = 0; i             //setobject占位符从1开始，但是我们的数组是从0开始
            preparedStatement.setobject（i+1params[i]）;
        }
        resultSet=preparedStatement.executeQuery（）;
        return  resultSet;
    }

    //编写增删改公共类
    public static int execute（Connection connectionPreparedStatement preparedStatement String sql object[] params） throws SQLException {
        preparedStatement = connection.prepareStatement（sql）;
        for （int i = 0; i             //setobject占位符从1开始，但是我们的数组是从0开始
            preparedStatement.setobject（i+1params[i]）;
        }
        int updateRows=preparedStatement.executeUpdate（）;
        return  updateRows;
    }

    //释放资源
    public static boolean closeResource（Connection connectionPreparedStatement preparedStatementResultSet resultSet）{
        Boolean flag = true;

        if（connection!=null）{
            try {
                connection.close（）;
                //GC回收
                connection=null;
            } catch （SQLException e） {
                e.printStackTrace（）;
                flag=false;
            }
        }

        if（preparedStatement!=null）{
            try {
                preparedStatement.close（）;
                //GC回收
                preparedStatement=null;
            } catch （SQLException e） {
                e.printStackTrace（）;
          

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     目录           0  2020-05-11 11:00  smbms
     目录           0  2020-05-11 11:02  smbms.git
     文件          13  2020-05-11 11:01  smbms.gitCOMMIT_EDITMSG
     文件          23  2020-05-11 11:00  smbms.gitHEAD
     文件         280  2020-05-11 12:55  smbms.gitconfig
     文件          73  2020-05-11 11:00  smbms.gitdescription
     目录           0  2020-05-11 11:00  smbms.githooks
     文件         478  2020-05-11 11:00  smbms.githooksapplypatch-msg.sample
     文件         896  2020-05-11 11:00  smbms.githookscommit-msg.sample
     文件        3079  2020-05-11 11:00  smbms.githooksfsmonitor-watchman.sample
     文件         189  2020-05-11 11:00  smbms.githookspost-update.sample
     文件         424  2020-05-11 11:00  smbms.githookspre-applypatch.sample
     文件        1638  2020-05-11 11:00  smbms.githookspre-commit.sample
     文件         416  2020-05-11 11:00  smbms.githookspre-merge-commit.sample
     文件        1348  2020-05-11 11:00  smbms.githookspre-push.sample
     文件        4898  2020-05-11 11:00  smbms.githookspre-rebase.sample
     文件         544  2020-05-11 11:00  smbms.githookspre-receive.sample
     文件        1492  2020-05-11 11:00  smbms.githooksprepare-commit-msg.sample
     文件        3610  2020-05-11 11:00  smbms.githooksupdate.sample
     文件          65  2020-05-11 11:01  smbms.gitindex
     目录           0  2020-05-11 11:00  smbms.gitinfo
     文件         240  2020-05-11 11:00  smbms.gitinfoexclude
     目录           0  2020-05-11 11:01  smbms.gitobjects
     目录           0  2020-05-11 11:01  smbms.gitobjects4b
     文件          15  2020-05-11 11:01  smbms.gitobjects4b825dc642cb6eb9a060e54bf8d69288fbee4904
     目录           0  2020-05-11 13:03  smbms.gitobjectsinfo
     目录           0  2020-05-11 13:03  smbms.gitobjectspack
     目录           0  2020-05-11 11:00  smbms.git
efs
     目录           0  2020-05-11 13:03  smbms.git
efsheads
     目录           0  2020-05-11 13:03  smbms.git
efs ags
     目录           0  2020-05-11 10:54  smbms.idea
............此处省略555个文件信息