java数据库系统开发案例精选_Java解析db文件

JAVADB数据库范例

关于javaDB的介绍就不说了，直接上例子。

首先将derby.jar添加到classpath下面(IDE的话直接引入)

import java.sql.*;

import java.util.*;

import java.io.*;

public class Test

{

public static void main(String[] args) throws Exception{

DBHelper db = new DBHelper();

db.createUserTable();

db.insertUser(1,”zhangsan2″,”123″);

db.insertUser(1,”zhangsan3″,”1233″);

db.insertUser(1,”zhangsan4″,”1234″);

db.insertUser(1,”zhangsan5″,”12345″);

ResultSet rs = db.query();

while(rs.next()){

int id = rs.getInt(“id”);

String name = rs.getString(“name”);

String pwd = rs.getString(“password”);

System.out.println(“id->” + id + “\tname->” + name + “\tpassword->” + pwd);

}

rs.close();

}

}

/**

* 数据库工具类

*/

class DBHelper

{

private Connection con = null ; //连接

public DBHelper(){

//loadDriver(“org.apache.derby.jdbc.EmbeddedDriver”); //load driver jdk6可以省略加载驱动这一步

getConnection(); //init Connection

}

//load driver class

private void loadDriver(String driveName){

try{

Class.forName(driveName);

}catch(Exception e){

e.printStackTrace();

System.out.println(“load driver failure”);

}

}

//get Connection

private void getConnection(){

try{

//con = DriverManager.getConnection(“jdbc:derby:userDB;create=true;user=test;password=test”);//userDB创建在class运行目录

//con = DriverManager.getConnection(“jdbc:derby:a/b/userDB;create=true;user=test;password=test”);//userDB创建在class下面的a/b文件夹下面，

con = DriverManager.getConnection(“jdbc:derby:d:/a/b/userDB;create=true;user=test;password=test”);//userDB创建在d盘下面的a/b文件夹下面，

}catch(Exception e){

e.printStackTrace();

}

}

//create simple table for test

public void createUserTable(){

try{

Statement stat = con.createStatement();

String sql_create = “create table tb_user(id int,name varchar(20),password varchar(20))”;

stat.execute(sql_create);

stat.close();

}catch(Exception e){

e.printStackTrace();

}

}

//insert user info

public void insertUser(int id,String name,String pwd){

String sql_insert = “insert into tb_user values (?,?,?)”;

try{

PreparedStatement pst = con.prepareStatement(sql_insert);

pst.setInt(1,id);

pst.setString(2,name);

pst.setString(3,pwd);

int i = pst.executeUpdate();

}catch(Exception e){

e.printStackTrace();

}

}

//query user info

public ResultSet query(){

String sql_insert = “select * from tb_user”;

try{

PreparedStatement pst = con.prepareStatement(sql_insert);

return pst.executeQuery();

}catch(Exception e){

e.printStackTrace();

}

return null;

}

}

result:

———- 直接运行 ———-

id->1 name->zhangsan2 password->123

id->1 name->zhangsan3 password->1233

id->1 name->zhangsan4 password->1234

id->1 name->zhangsan5 password->12345

Output completed (7 sec consumed) – Normal Termination