新建 *.properties属性文件，内容如下：
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/dbName
username=root
password=root
public class DbTool {
private static String db_driver=null;
private static String db_url=null;
private static String db_user=null;
private static String db_password=null;
public static Connection getConnection() throws ClassNotFoundException, IOException{
Connection conn=null;
InputStream in=DbTool.class.getClassLoader().getResourceAsStream("jdbc.properties");
Properties properties=new Properties();
properties.load(in);
db_driver=properties.getProperty("driver");
db_url=properties.getProperty("url");
db_user=properties.getProperty("user");
db_password=properties.getProperty("password");
try {
Class.forName(db_driver);
conn=DriverManager.getConnection(db_url,db_user,db_password);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// TODO Auto-generated catch block
// TODO Auto-generated catch block
return conn;
}
public static void close(ResultSet rs){
if(rs!=null){
try {
rs.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public static void close(PreparedStatement prst){
if(prst!=null){
try {
prst.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public static void close(Connection conn){
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public static void close(PreparedStatement prst,Connection conn){
close(prst);
close(conn);
}
public static void close(ResultSet rs,PreparedStatement prst,Connection conn){
close(rs);
close(prst);
close(conn);
}
}