这个JAVA程序错在哪了?麻烦大虾帮忙解答，急用！

package ArrayText;
import java.lang.*;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.StringSelection;
import java.awt.datatransfer.Transferable;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.print.PageFormat;
import java.awt.print.PrinterJob;
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;

import javax.swing.Box;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.event.UndoableEditEvent;
import javax.swing.event.UndoableEditListener;
import javax.swing.text.PlainDocument;
import javax.swing.undo.UndoManager;
public class ArrayText {
class man
{
private String name;
private int age;
private float height;
private float weight;
public void setname()//设置姓名
{
this.name="李哲";
}
public void setage(int a)//设置年龄
{
this.age=a;
}
public void setheight(float h)//设置身高
{
this.height=h;
}
public void setweight(float w)//设置体重
{
this.weight=w;
}
public void display()
{
System.out.println("学生姓名："+name);
System.out.println("学生年龄:"+age);
System.out.print("学生身高："+height);
System.out.println("cm\n学生体重："+weight);
}
}
class Student extends man
{
private float sxcj;
public void sets(float s)
{
this.sxcj=s;
}
public void display()
{
super.display();
System.out.println("学生成绩："+sxcj);
}
}
public static void main(String[] args)
{
Student s1=new student();
s1.setname();
s1.setage(20);
s1.setheight(183);
s1.setweight(60);
s1.sets(87);
s1.display();
}
}