通过JDBC连接数据库时，各个数据库有着不同的URL格式，为了方便大家使用，我在以下提供了常见的7种数据库连接示例代码，请根据实际需要进行相应的更改。

1.Oracle数据库

Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();

String url = "jdbc:oracle:thin:@localhost:1521:orcle";

String user = "test";

String password = "test";

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

2.DB2数据库

Class.forName("com.ibm.db2.jdbc.app.DB2Driver").newInstance();

String url = "jdbc:db2://localhost:5000/testDB";

String user = "admin";

String password = "test";

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

3.SQL Server数据库

Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();

String url = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=testDB";

String user = "sa";

String password = "test";

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

4. Sybase数据库

Class.forName("com.sybase.jdbc.SybDriver").newInstance();

String url = "jdbc:sybase:Tds:localhost:5007/testDB";

Properties sysProps = System.getProperties();

sysProps.put("user", "userid");

sysProps.put("password", "user_password");

Connection conn = DriverManager.getConnection(url, sysProps);

5.Informix数据库

Class.forName("com.infoxmix.jdbc.IfxDriver").newInstance();

String url = "jdbc:infoxmix-sqli://localhost:1533/testDB:INFORMIXSERVER=myserver;user=testuser;password=testpassword";

Connection conn = DriverManager.getConnection(url);

6.MySQL数据库

Class.forName("org.gjt.mm.mysql.Driver").newInstance();

String url = "jdbc:mysql://localhost/testDB?user=testuser&password=testpassword&useUnicode=true&characterEncoding=GB2312";

Connection conn = DriverManager.getConnection(url);

7.PostgreSQL数据库

Class.forName("org.postgresql.Driver").newInstance();

String url = "jdbc:postgresql://localhost/testDB";

String user = "myuser";

String password = "test";

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