帮我写一个jdbc封装类
时间: 2023-07-07 14:44:41 浏览: 58
好的,下面是一个简单的JDBC封装类的示例代码:
```java
import java.sql.*;
public class JdbcUtils {
private static String url = "jdbc:mysql://localhost:3306/test";
private static String username = "root";
private static String password = "123456";
public static Connection getConnection() throws ClassNotFoundException, SQLException {
Class.forName("com.mysql.jdbc.Driver");
return DriverManager.getConnection(url, username, password);
}
public static void close(Connection conn, Statement stmt, ResultSet rs) {
try {
if (rs != null)
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
try {
if (stmt != null)
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
try {
if (conn != null)
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
try {
conn = JdbcUtils.getConnection();
stmt = conn.createStatement();
rs = stmt.executeQuery("SELECT * FROM user");
while (rs.next()) {
int id = rs.getInt("id");
String username = rs.getString("username");
String password = rs.getString("password");
System.out.println("id=" + id + ", username=" + username + ", password=" + password);
}
} catch (ClassNotFoundException | SQLException e) {
e.printStackTrace();
} finally {
JdbcUtils.close(conn, stmt, rs);
}
}
}
```
这个封装类提供了getConnection()方法用于获取数据库连接,close()方法用于关闭数据库连接、语句和结果集。在main()方法中,我们可以使用这个封装类来查询数据库中的用户表,并输出查询结果。
你可以根据自己的需要对这个示例代码进行修改和完善。