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);
