jdbc 读取属性文件

jdbc读取属性文件连接数据库 源代码如下

?//======DbConnection类如下 package util;

?import java.io.InputStream;

import java.sql.Connection;

?import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.Statement;

?import java.util.Properties;

?

public class DbConnection extends Properties {

private static final long serialVersionUID = 1L;

?private static DbConnection instance;

public static DbConnection getInstance() {

?if (instance != null) {

return instance;

?} else {

?makeInstance();

return instance;

}

}

private static synchronized void makeInstance() {

?if (instance == null) {

instance = new DbConnection();

?} }

?private DbConnection() {

InputStream is = getClass().getResourceAsStream("db.properties");

try {

?load(is);

?} catch (Exception e) {

System.out.println("错误：没有读取属性文件，" + "请确认db.properties文件是否存在"); } }

?public static synchronized Connection getConnection() {

Connection conn = null;

String driverClassName = DbConnection.getInstance().getProperty("driver");

?String url = DbConnection.getInstance().getProperty("url");

String user = DbConnection.getInstance().getProperty("user");

String password = DbConnection.getInstance().getProperty("password");

?try {

Class.forName(driverClassName);

conn = DriverManager.getConnection(url, user, password);

} catch (Exception e) {

?System.out.println("数据库连接错误！");

e.printStackTrace();

?}

return conn; }

public static void close(

Connection con,

Statement st){ close(con); close(st);

?}

?public static void close(

Connection con,Statement st,ResultSet rs){

close(con,st); close(rs); }

?public static void close(Connection con){ try{ con.close(); }catch(Exception e){ } } public static void close(Statement st){ try{ st.close(); }catch(Exception e){ } } public static void close(ResultSet rs){ try{ rs.close(); }catch(Exception e){ } } }

//==============新建属性文件 如下注：属性文件的名称为：

db.properties 他们在同一级目录下

driver=com.mysql.jdbc.Driver

url=jdbc:mysql://localhost/jiraplugin

user=root password=root