mysql数据库网址，用户名和密码在文件中

Question

我怎样才能将我的mysql数据库url，用户名和密码放在一个文件中，我如何访问它们以便在我的java代码中使用，而不是硬编码它们。我试过谷歌，但没有得到明确的方向

Answer 1

创建一个properties file。您可以通过the Properties API加载它。

E.g. config.properties：

url = jdbc:mysql://localhost:3306/dbname 
username = foo 
password = bar 

然后，你可以加载和阅读如下（你把它夹在类路径后）：

Properties config = new Properties(); 
config.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("config.properties")); 

String url = config.getProperty("url"); 
String username = config.getProperty("username"); 
String password = config.getProperty("password"); 
// ... 

Answer 2

/** 
* Function that connects to a DB and data fro connection is loaded from a properties file 
* @param fileName 
* @return the connection to DB or null if any problem 
*/ 
public java.sql.Connection connect_to_database_from_properties(String fileName) 
{ 
    Properties prop = new Properties(); 

    InputStream is; 
    try { 
     is = new FileInputStream(fileName); 

    prop.load(is); 
    String url=prop.getProperty("url"); 
    String un=prop.getProperty("username"); 
    String pass=prop.getProperty("password"); 
    System.out.println("URL: "+url+" UN: "+un+" PASS: "+pass); 
    is.close(); 
    Class.forName("com.mysql.jdbc.Driver"); 

    java.sql.Connection conection =DriverManager.getConnection(url, un, pass); 
    return conection; 

    } catch (FileNotFoundException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } catch (IOException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } catch (ClassNotFoundException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } catch (SQLException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 
    return null; 

}