JDBC连接工具类

package com.ins.db;import java.io.IOException;import java.io.InputStream;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.Properties;public class DBconn {//declare var private String driver="";private String url="";private String uname="";private String passwd="";private Connection conn=null;private Statement stmt=null;private static ResultSet rs=null;private static final String DATABASE_PROPERTIES="jdbc.properties";//定义配置文件//load propertiespublic DBconn(){loadProperties();setConn();}//load confprivate void loadProperties(){InputStream in =DBconn.class.getResourceAsStream(DATABASE_PROPERTIES);//读入配置文件//定义PropertiesProperties p=new Properties();try {p.load(in);} catch (IOException e) {e.printStackTrace();}//得到配置文件并将其值赋给当前变量this.driver=p.getProperty("driver");this.url=p.getProperty("url");this.uname=p.getProperty("username");this.passwd=p.getProperty("password");}//setConnprivate void setConn(){try {Class.forName(driver);  this.conn=DriverManager.getConnection(url,uname,passwd);} catch (ClassNotFoundException e) {e.printStackTrace();} catch (SQLException e) {e.printStackTrace();}}//getConnpublic  Connection getConn(){return this.conn;}//=================================CRUD===========================//执行插入public  void doInsert(String sql){try {stmt=conn.createStatement();stmt.executeUpdate(sql);} catch (SQLException e) {e.printStackTrace();System.err.println("db.executeInset:" + e.getMessage());   }finally{colseAll(rs,stmt,conn);}}//执行删除public  void doDelete(String sql){try {stmt=conn.createStatement();stmt.executeUpdate(sql);} catch (SQLException e) {e.printStackTrace();System.err.println("db.executeInset:" + e.getMessage());   }finally{colseAll(rs,stmt,conn);}}//执行更新public  void doUpdate(String sql){try {stmt=conn.createStatement();stmt.executeUpdate(sql);} catch (SQLException e) {e.printStackTrace();System.err.println("db.executeInset:" + e.getMessage());   }finally{colseAll(rs,stmt,conn);}}//查询结果集       public  ResultSet doSelect(String sql) {           try {               stmt = conn.createStatement(java.sql.ResultSet.TYPE_SCROLL_INSENSITIVE,java.sql.ResultSet.CONCUR_READ_ONLY);               rs = stmt.executeQuery(sql);           } catch(SQLException sqlexception) {               System.err.println("db.executeQuery: " + sqlexception.getMessage());           }           return rs;       }     //=============================================CRUD end========================//close rspublic  static void colseRs(ResultSet rs){if(rs!=null){try {rs.close();} catch (SQLException e) {e.printStackTrace();}rs=null;}}//close stmtpublic  static void colseStmt(Statement stmt){if(stmt!=null){try {stmt.close();} catch (SQLException es) {es.printStackTrace();}stmt=null;}}//close connpublic  void colseConn(Connection conn){if(conn!=null){try {conn.close();} catch (SQLException ec) {ec.printStackTrace();}conn=null;}}//close allpublic static void colseAll(ResultSet rs,Statement stmt,Connection conn){if(rs!=null){try {rs.close();} catch (SQLException e) {e.printStackTrace();}rs=null;}if(stmt!=null){try {stmt.close();} catch (SQLException es) {es.printStackTrace();}stmt=null;}if(conn!=null){try {conn.close();} catch (SQLException ec) {ec.printStackTrace();}conn=null;}}public static void main(String[] args) {DBconn db=new DBconn();String sql="select *from class";rs=db.doSelect(sql);try {while(rs.next()){System.out.println(rs.getInt(1));System.out.println(rs.getString(2));}} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}

MySQL：           String Driver="com.mysql.jdbc.Driver";    //驱动程序       String URL="jdbc:mysql://localhost:3306/db_name";    //连接的URL,db_name为数据库名           String Username="username";    //用户名       String Password="password";    //密码       Class.forName(Driver).new Instance();       Connection con=DriverManager.getConnection(URL,Username,Password);   Microsoft SQL Server 2.0驱动(3个jar的那个):       String Driver="com.microsoft.jdbc.sqlserver.SQLServerDriver";    //连接SQL数据库的方法       String URL="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=db_name";    //db_name为数据库名       String Username="username";    //用户名       String Password="password";    //密码       Class.forName(Driver).new Instance();    //加载数据可驱动       Connection con=DriverManager.getConnection(URL,UserName,Password);    //   Microsoft SQL Server 3.0驱动(1个jar的那个): // 老紫竹完善       String Driver="com.microsoft.sqlserver.jdbc.SQLServerDriver";    //连接SQL数据库的方法       String URL="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=db_name";    //db_name为数据库名       String Username="username";    //用户名       String Password="password";    //密码       Class.forName(Driver).new Instance();    //加载数据可驱动       Connection con=DriverManager.getConnection(URL,UserName,Password);    //   Sysbase:       String Driver="com.sybase.jdbc.SybDriver";    //驱动程序       String URL="jdbc:Sysbase://localhost:5007/db_name";    //db_name为数据可名       String Username="username";    //用户名       String Password="password";    //密码       Class.forName(Driver).newInstance();           Connection con=DriverManager.getConnection(URL,Username,Password);   Oracle(用thin模式):       String Driver="oracle.jdbc.driver.OracleDriver";    //连接数据库的方法       String URL="jdbc:oracle:thin:@loaclhost:1521:orcl";    //orcl为数据库的SID       String Username="username";    //用户名       String Password="password";    //密码       Class.forName(Driver).newInstance();    //加载数据库驱动       Connection con=DriverManager.getConnection(URL,Username,Password);       PostgreSQL:       String Driver="org.postgresql.Driver";    //连接数据库的方法       String URL="jdbc:postgresql://localhost/db_name";    //db_name为数据可名       String Username="username";    //用户名       String Password="password";    //密码       Class.forName(Driver).newInstance();           Connection con=DriverManager.getConnection(URL,Username,Password);   DB2：       String Driver="com.ibm.db2.jdbc.app.DB2.Driver";    //连接具有DB2客户端的Provider实例       //String Driver="com.ibm.db2.jdbc.net.DB2.Driver";    //连接不具有DB2客户端的Provider实例       String URL="jdbc:db2://localhost:5000/db_name";    //db_name为数据可名       String Username="username";    //用户名       String Password="password";    //密码       Class.forName(Driver).newInstance();           Connection con=DriverManager.getConnection(URL,Username,Password);   Informix:       String Driver="com.informix.jdbc.IfxDriver";           String URL="jdbc:Informix-sqli://localhost:1533/db_name:INFORMIXSER=myserver";    //db_name为数据可名       String Username="username";    //用户名       String Password="password";    //密码       Class.forName(Driver).newInstance();           Connection con=DriverManager.getConnection(URL,Username,Password);   JDBC-ODBC:       String Driver="sun.jdbc.odbc.JdbcOdbcDriver";       String URL="jdbc:odbc:dbsource";    //dbsource为数据源名       String Username="username";    //用户名       String Password="password";    //密码       Class.forName(Driver).newInstance();           Connection con=DriverManager.getConnection(URL,Username,Password);