NullPointerException in closing jdbc connection

Question

While I am trying to close the JDBC it is throwing NullPointerException .

public void getDBConnection() throws SQLException {
    Driver driver = new Driver();
    DriverManager.registerDriver(driver);
    conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test", "root", "root123");
}

public void closeDB() throws SQLException {
    conn.close();
}

Answer 1

you have to assure before close connection that conn instance initialized or not. so once need to call getDBConnection method, because conn object initialize in it. then you can call closeDB . Add check like if(conn != null) to be safe side.

Answer 2

Use try-with-resource statement of Java 7. It is AutoCloseable by default. It is safe and easy. For example,

 try(Connection con=DriverManager.getConnection(..)){

 }