DBUtil类 用于从配置文件中加载数据库属性信息，获取连接和关闭连接。
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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.sql.Statement;
import java.util.Properties;
/**
* 这是一个工具类，用于得到连接和关闭连接
*/
public class DBUtil
{
private static Connection ct=null;//连接
private static ResultSet rs=null;//结果
private static PreparedStatement ps=null;
//连接数据库参数
private static String url = "";
private static String drivername = "";
private static String username = "";
private static String password = "" ;
//加载驱动，一次
static{
try
{
Properties properties=new Properties();
InputStream is=DBUtil.class.getClassLoader().getResourceAsStream("dbInfo.properties");
properties.load(is);
//属性文件读取信息
drivername=properties.getProperty("driver");
username=properties.getProperty("username");
password=properties.getProperty("password");
url=properties.getProperty("url");
} catch (Exception e) {
e.printStackTrace();
System.exit(-1);
}
}
//得到连接
public static Connection getCon()
{
try {
Class.forName(drivername);
ct= DriverManager.getConnection(url, username, password);//从配置文件中读的
} catch (Exception e) {
e.printStackTrace();
}
return ct;//谁调用谁拿到Connection
}
//关闭资源函数
public static void close(ResultSet rs,Statement ps,Connection ct)
{
if(rs!=null)
{
try
{
rs.close();
}catch(Exception e)
{
}
rs=null;//使用垃圾回收
}
if(ps!=null)
{
try
{
ps.close();
}catch(SQLException e)
{
e.printStackTrace();
}
ps=null;
}
if(ct!=null)
{
try
{
ct.close();
}catch(SQLException e)
{
e.printStackTrace();
}
ct=null;
}
}
}
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.sql.Statement;
import java.util.Properties;
/**
* 这是一个工具类，用于得到连接和关闭连接
*/
public class DBUtil
{
private static Connection ct=null;//连接
private static ResultSet rs=null;//结果
private static PreparedStatement ps=null;
//连接数据库参数
private static String url = "";
private static String drivername = "";
private static String username = "";
private static String password = "" ;
//加载驱动，一次
static{
try
{
Properties properties=new Properties();
InputStream is=DBUtil.class.getClassLoader().getResourceAsStream("dbInfo.properties");
properties.load(is);
//属性文件读取信息
drivername=properties.getProperty("driver");
username=properties.getProperty("username");
password=properties.getProperty("password");
url=properties.getProperty("url");
} catch (Exception e) {
e.printStackTrace();