十分有用的代码：JDBC连接DB2、Oracle、MySQL、PostgreSQL，并取当前时间

package com.terac.util;

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

public class DBTest {
public static void main(String[] args) {
try {
String user = "user";
String password = "password";
String driver = "COM.ibm.db2.jdbc.net.DB2Driver";
//"oracle.jdbc.driver.OracleDriver";
//"com.mysql.jdbc.Driver";
//"org.postgresql.Driver";
String url = "jdbc:db2://localhost/a";
//"jdbc:oracle:thin:@localhost:1521:a";
//"jdbc:mysql://localhost/a";
//"jdbc:postgresql://localhost:5740/a";
String sql = "SELECT current timestamp FROM sysibm.sysdummy1";
//"SELECT sysdate FROM dual";
//"SELECT now()";
//"SELECT current_timestamp";
Class.forName(driver).newInstance();
Connection c = DriverManager.getConnection(url, user, password);
Statement stmt = c.createStatement();
ResultSet rs = stmt.executeQuery(sql);
while (rs.next()) {
System.out.println(rs.getString(1));
}
} catch (Exception e) {
e.printStackTrace();
}
}
}