Oracle Database connectivity with java : <p>Connectivity code</p>

<pre><code>username="system";
 password="oracle11";
 url="jdbc:oracle:thin:@localhost:1523:system";
 Driver="oracle.jdbc.driver.OracleDriver";
 Class.forName(this.Driver);
 this.con=DriverManager.getConnection(this.url,this.username,this.password);
 System.out.println("Connect");
</code></pre>

<p>In the url "system" is globally connect to the oracle it access all the tables so no database security or sepration is there so how to differentiate it.I want to create diffrent database for diffrent projects how to make it in oracle and how to access with java </p>
