期中考试前准备--数据库查找代码

import java.sql.*;

import java.util.Scanner;

public class jdbcselect {
	public static void main(String[]args) {
		final String URL = "jdbc:mysql://localhost:3306/test";
		final String USERNAME = "root";
	    final String PWD = "12345";
	    Connection connection = null;
	    Statement  stmt = null;
	    ResultSet rs = null ; 
		Scanner con=new Scanner(System.in);
		String idnumber;
		String classname;
		String teachername;
		String didian;

		teachername=con.nextLine();
		/*teachername=con.nextLine();
		didian=con.nextLine();*/
		try {
			// a.导入驱动，加载具体的驱动类
			Class.forName("com.mysql.jdbc.Driver");// 加载具体的驱动类
			// b.与数据库建立连接
			connection = DriverManager.getConnection(URL, USERNAME, PWD);
			stmt = connection.createStatement();
			
			
			//String sql = "select * from student where teacher='"+teachername+"'  " ;
			String sql = "select * from student where teacher like '%"+teachername+"%'  " ;
		
			// 执行SQL
			rs = stmt.executeQuery(sql);
			
			// d.处理结果
			
		 
				
				while(rs.next()) { 
					String id=rs.getString("id");
					System.out.println(id);
					}
				
			
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
			System.out.println("1");
		} catch (SQLException e) {
			e.printStackTrace();
			System.out.println("3");
		} catch(Exception e) {
			e.printStackTrace();
			System.out.println("2");
		}
		finally {
			try {
				 if(stmt!=null) stmt.close();// 对象.方法
				 if(connection!=null)connection.close();
			}catch(SQLException e) {
				e.printStackTrace();
			}
		}
	}


}