java使用JDBC连接数据库

//查询数据
public class Test {
	public static void main(String[] args) {
		Connection conn=null;
		PreparedStatement pstmt=null;
		ResultSet rs=null;
		try {
			//1.加载驱动
			Class.forName("com.mysql.jdbc.Driver");
			//2.建立连接数据库对象
			String url="jdbc:mysql://localhost:3306/Student_mag";
			String user="root";
			String password="admin";
			conn=DriverManager.getConnection(url,user,password);
			//3.创建sql语句
			String sql="SELECT studentNo,studentName FROM student WHERE sex=?";
			//4.创建对象：预编译sql语句
			pstmt=conn.prepareStatement(sql);
			//为占位符赋值：第一个是占位符的位置，第二个是里面的值
			pstmt.setString(1, "男");  
			//5.执行sql语句
			rs= pstmt.executeQuery();
			//6.处理结果
			System.out.println("学号"+"\t"+"姓名");
			while(rs.next()) {
				int stuNo=rs.getInt("studentNo");
				String stuName=rs.getString("studentName");
				System.out.println(stuNo+"\t"+stuName);
			}
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			//7.释放资源：先判断是否为null，先开的后关，后开的先关
			if(null!=rs) {
				try {
					rs.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
			if(null!=pstmt) {
				try {
					pstmt.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
			if(null!=conn) {
				try {
					conn.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
		}
	}
}