Several Methods for connecting to the database using JDBC and jdbc

Several Methods for connecting to the database using JDBC and jdbc

I. Oldest method (directly connect to the database through the Driver Interface)

 

Instance code:

1 @ Test 2 public void testDriver () throws SQLException {3 // 1. create a Driver implementation Class Object 4 Driver dirver = new com. mysql. jdbc. driver (); 5 6 // 2. prepare the basic information for connecting to the database: url, user, password 7 String url = "jdbc: mysql: // 127.0.0.1: 3306/java_jdbc"; 8 Properties info = new Properties (); 9 info. put ("user", "root"); 10 info. put ("password", "123456"); 11 12 // 3. call the connect (url, info) on the Driver excuse to obtain the database Connection 13 connection Connection = dirver. connect (url, info); 14 System. out. println (connection); 15}

View Code

 

 

2. Compile a general method (throughDriver Interface implementation)

 

Instance code:

1 public Connection getConnection () throws Exception {2 String driverClass = null; 3 String jdbcUrl = null; 4 String user = null; 5 String password = null; 6 7 // read jdbc in the class path. properties file 8 InputStream in = getClass (). getClassLoader (). getResourceAsStream ("jdbc. properties "); 9 Properties properties = new Properties (); 10 properties. load (in); 11 12 driverClass = properties. getProperty ("driver"); 13 jdbcUrl = properties. getProperty ("jdbcUrl"); 14 user = properties. getProperty ("user"); 15 password = properties. getProperty ("password"); 16 17 // create the Driver object 18 Driver driver = (Driver) Class through reflection. forName (driverClass ). newInstance (); 19 20 Properties info = new Properties (); 21 info. put ("user", user); 22 info. put ("password", password); 23 24 // connect to the database through the connect Method of the Driver. 25 Connection connection = driver. connect (jdbcUrl, info); 26 27 return connection; 28} 29 30 @ Test31 public void testGetConnection () throws Exception {32 System. out. println (getConnection (); 33}

View Code

 

3. Obtain the database connection through the DriverManager driver management class

 

 

 

1). Create a properties object

1 Properties properties = new Properties();

 

2). Obtain the input stream corresponding to jdbc. properties.

1 InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream("jdbc.properties");

 

3) load the corresponding input stream

1     properties.load(inputStream);

 

4). The user, password, url, and driver strings are determined.

1 String driver = properties.getProperty("driver");2 String jdbcUrl = properties.getProperty("jdbcUrl");3 String user = properties.getProperty("user");4 String password = properties.getProperty("password");

2. Load the database driver

1 Class.forName(driver);

 

3. Get the database connection through the getConnection () method of Drivermanager

1 return DriverManager.getConnection(jdbcUrl, user, password);

 

 

Instance code:

 1     @Test 2     public void testGetConnection23() throws Exception { 3         System.out.println(getConnection2()); 4     } 5     public Connection getConnection2() throws IOException, ClassNotFoundException, SQLException{ 6          7         Properties properties = new Properties(); 8          9         InputStream inputStream = this.getClass().getClassLoader().getResourceAsStream("jdbc.properties");10         11         properties.load(inputStream);12         13         String driver = properties.getProperty("driver");14         String jdbcUrl = properties.getProperty("jdbcUrl");15         String user = properties.getProperty("user");16         String password = properties.getProperty("password");17         18         Class.forName(driver);19         20         return DriverManager.getConnection(jdbcUrl, user, password);21     }

View Code

 

This article is just the author's note and is for reference only. If you have any mistakes, please note it! 2017-10-28 11:14:03