一找不到或无法加载主类，二插入语句思路混乱，三final语句一直报错。

Question

package my;
import java.io.*;
import java.util.*;
import java.sql.*;
import javax.sql.*;
import java.awt.*;
import javax.swing.*;import java.awt.event.*;
import java.applet.*;
public class my extends Applet implements ActionListener
{
	JTextField snotext,snametext,sagetext,ssextext;
	JButton queryButton,clearButton;
	
	public void main() 
	{
		new Object();
		
	}
	public void init() 
	{
		JLabel snoLabel=new JLabel("学号:");
		JLabel snameLabel=new JLabel("姓名:");
		JLabel sageLabel=new JLabel("年龄:");
		JLabel ssexLabel=new JLabel("性别:");
		
		snotext=new JTextField(15);
		snametext=new JTextField(15);
		sagetext=new JTextField(15);
		ssextext=new JTextField(15);
		
		queryButton=new JButton("添加");
		clearButton=new JButton("清除");
		
		setLayout(null);
		
		snoLabel.setBounds(10, 27, 90, 24);		snotext.setBounds(106, 24, 176, 30);
		snameLabel.setBounds(10, 70, 90, 24);	snametext.setBounds(106, 67, 176, 30);
		sageLabel.setBounds(10, 112, 90, 24);	sagetext.setBounds(106, 112, 176, 30);
		ssexLabel.setBounds(10, 156, 90, 24);	ssextext.setBounds(106, 156, 176, 30);
		queryButton.setBounds(10, 230, 114, 34);	clearButton.setBounds(208, 230, 114, 34);
		
		add(snoLabel);   add(snotext);
		add(snameLabel);   add(snametext);
		add(sageLabel);   add(sagetext);
		add(ssexLabel);   add(ssextext); 
		add(queryButton);add(clearButton);
		queryButton.addActionListener(this);
		clearButton.addActionListener(this);
		
		String driverName="com.microsoft.sqlserver.jdbc.SQLServerDriver";
		String dbURL="jdbc:sqlserver://localhost:1433;DatabaseName=java.jdbc_test";  
		String userName="sa";  
		String userPwd="123456"; 
		
		try
		{	Class.forName(driverName);
		    Connection dbConn=DriverManager.getConnection(dbURL,userName,userPwd);
		    PreparedStatement stmt=dbConn.prepareStatement("insert into t_user(userName,userPwd) values(?,?,?,?)");
		    stmt.setString(1,snotext.getText());	
		    stmt.setString(2,snametext.getText());
		    stmt.setString(3,sagetext.getText());
		    stmt.setString(4,ssextext.getText());
		
		}
		catch(Exception e)
		{	e.printStackTrace();System.out.println("失败!");		}
		//finally 
		//{	ConnectionPool.close(stmt,conn);	}
		
		
		
	}
	public void actionPerformed(ActionEvent e) 
	{
		Float sno_gettext=Float.parseFloat(snotext.getText());
		
		if(e.getSource()==queryButton)
		{
			String driverName="com.microsoft.sqlserver.jdbc.SQLServerDriver";
			String dbURL="jdbc:sqlserver://localhost:1433;DatabaseName=java.jdbc_test";  
			String userName="sa";  
			String userPwd="123456"; 
			
			try
			{	Class.forName(driverName);
			    Connection dbConn=DriverManager.getConnection(dbURL,userName,userPwd);
			    PreparedStatement stmt=dbConn.prepareStatement("insert into t_user(userName,userPwd) values(?,?,?,?)");
			    stmt.setString(1,snotext.getText());	
			    stmt.setString(2,snametext.getText());
			    stmt.setString(3,sagetext.getText());
			    stmt.setString(4,ssextext.getText());
			
			}
			catch(Exception e1)
			{	e1.printStackTrace();System.out.println("失败!");		}
			finally 
			{	ConnectionPool.close(stmt,conn);	}
		    
		    
		}
		//getSource得到的组件的名称，而getActionCommand得到的是标签。 
	    //resultTF.setText(String.valueOf(result)); [String.toString];
		
		if(e.getSource()==clearButton)
		{snotext.setText("");snametext.setText(null);
		 sagetext.setText(null);ssextext.setText(null);}
		
	}
	
	


}

Answer 1

main方法中，new Object();改为new my();