JDBC 复习1 DBUtil

package dbex;

import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;

import org.apache.commons.dbutils.DbUtils;
/**
*
* @ClassName: TestOraDB
* @Description: Oracle数据库测试 JDBC
* @author penny
* @date 2017年11月24日 上午11:40:01
*
*/
public class DBUtil {
/**
* 连接对象
*/
public static Connection conn = null;
/**
* 预处理SQL语句
*/
public static PreparedStatement prst=null;
/**
* 返回结果集
*/
public static ResultSet rs = null;
public static Properties pro=null;

static{
try {
InputStream in = DBUtil.class.getResourceAsStream("../database.properties");
pro = new Properties();
pro.load(in);
Class.forName(pro.getProperty("driver"));
} catch (Exception e) {
System.out.println("加载驱动失败："+e.getMessage());
}
}
/**
*
* @Title: getConnection
* @Description: 获取连接
* @param @return
* @param @throws SQLException 设定文件
* @return Connection 返回类型
* @throws
*/
public static Connection getConnection() throws SQLException{
//	System.out.println(pro.getProperty("url"));
//	System.out.println(pro.getProperty("user"));
//	System.out.println(pro.getProperty("password"));
conn=DriverManager.getConnection(pro.getProperty("url"), pro.getProperty("user"), pro.getProperty("password"));
if(conn==null){
return null;
}else{
return conn;
}
}
/**
*
* @Title: executeQuery
* @Description: 执行查询
* @param @param sql
* @param @throws SQLException
* @throws
*/
public static void executeQuery(String sql) throws SQLException{
prst = (PreparedStatement) conn.prepareStatement(sql);
rs=prst.executeQuery();
while (rs.next()) {
System.out.println(rs.getString(1)+"\t"+rs.getString(2));
}
}

public static void closeAll
(Connection a, PreparedStatement b, ResultSet c) throws IOException{
DbUtils.closeQuietly(a, b, c);
}

public static void main(String[] args) throws Exception {
DBUtil db =new DBUtil();
db.getConnection();
db.executeQuery("select * from ex_clob");
db.closeAll(conn, prst, rs);
}
}

下面是连接配置文件database.properties

### Oracle
url=jdbc:oracle:thin:@localhost:1521:orcl
user=scott
password=tiger
driver=oracle.jdbc.driver.OracleDriver
### MySql
#url=jdbc:mysql://localhost:3306/libweb
#driver=com.mysql.jdbc.Driver
#user=root
#password=