java 本地数据库的javaDB

java的自带数据库，觉得挺方便的就实验了下  

package com.gemantic.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;

public class JavaDBTest {

    public static void main(String[] args) throws Exception {
        String driver = "org.apache.derby.jdbc.EmbeddedDriver";
        String url = "jdbc:derby:";
        String facetDir = "/data/javaDB/";
        Class.forName(driver).newInstance();
        Connection connection = DriverManager.getConnection(url + facetDir+ ";create=true");
        connection.setAutoCommit(true);
        Statement stmt = connection.createStatement();
        String creatSql="CREATE TABLE  testDB (" + "facetId INTEGER PRIMARY KEY," + " name VARCHAR(256))";
        stmt.executeUpdate(creatSql);
        stmt.executeUpdate("INSERT INTO testDB(facetId, name) " + "VALUES(1, '123')");
        stmt.executeUpdate("INSERT INTO testDB(facetId, name) " + "VALUES(2, '123')");
        stmt.executeUpdate("INSERT INTO testDB(facetId, name) " + "VALUES(3, '123')");
    }
}

这样就会在相应的位置建立一个数据库，create=true ，若数据库已经存在的话打开原来的数据库，不然的话重新创建一个数据库 。