sql工具类tool

importjava.io.IOException;
    importjava.sql.*;
    importjava.util.List;
    importjava.util.Properties;
    publicclasstool{
    toolk=newtool();
    privatestaticStringurl=null;
    privatestaticStringusername=null;
    privatestaticStringpassword=null;
    privatestaticPropertiesprops=newProperties();
    static{
    try{
    props.load(tool.class.getResourceAsStream("/jdbc.properties"));
    }catch(IOExceptione){
    e.printStackTrace();
    System.out.println("加载properties文件异常");
    }
    url=(props.getProperty("jdbc.url"));
    username=(props.getProperty("jdbc.username"));
    password=(props.getProperty("jdbc.password"));
    //注册驱动类
    try{
    Class.forName("com.mysql.jdbc.Driver");
    }catch(ClassNotFoundExceptione){
    e.printStackTrace();
    System.out.println("加载驱动异常");
    }
    }
    /**
    *创建一个数据库连接
    *
    *@return一个数据库连接
    */
    publicstaticConnectiongetConnection(){
    Connectionconn=null;
    //创建数据库连接
    try{
    conn=DriverManager.getConnection(url,username,password);
    }catch(SQLExceptione){
    e.printStackTrace();
    System.out.println("数据库连接出错");
    }
    returnconn;
    }
    
    publicstaticResultSetexecuteQuery(Connectionconn,StringstaticSql){
    ResultSetrs=null;
    try{
    //创建执行SQL的对象
    Statementstmt=conn.createStatement();
    //执行SQL，并获取返回结果
    rs=stmt.executeQuery(staticSql);
    }catch(SQLExceptione){
    e.printStackTrace();
    }
    returnrs;
    }
    
    publicstaticvoidexecuteSQL(Connectionconn,StringstaticSql){
    try{
    //创建执行SQL的对象
    Statementstmt=conn.createStatement();
    //执行SQL，并获取返回结果
    stmt.execute(staticSql);
    }catch(SQLExceptione){
    e.printStackTrace();
    System.out.println("执行SQL语句出错");
    }
    }
    
    publicstaticvoidexecuteBatchSQL(Connectionconn,ListsqlList){
    try{
    //创建执行SQL的对象
    Statementstmt=conn.createStatement();
    for(Stringsql:sqlList){
    stmt.addBatch(sql);
    }
    //执行SQL，并获取返回结果
    stmt.executeBatch();
    }catch(SQLExceptione){
    e.printStackTrace();
    System.out.println("");
    }
    }
    publicstaticvoidcloseConnection(Connectionconn){
    if(conn==null)return;
    try{
    if(!conn.isClosed()){
    //关闭数据库连接
    conn.close();
    }
    }catch(SQLExceptione){
    e.printStackTrace();
    System.out.println("关闭数据库异常");
    }
    }
    publicvoidclose(Connectionconnection){
    //TODOAuto-generatedmethodstub
    }
    }