用java做个下载器难不难？、

Posted 2023-05-13

快做项目了，也是我开始学习java的第一个项目，怎么做啊？用到那些知识都是？？还望达人给说下，谢谢

不难，用swing做，写的比较完善就会占内存很大，我想下载器应该不是很专业的，支持断点吗？不过还是有些搞头。追问

呵呵呵，行，我得努力，呵呵！

参考技术A 你好，请问高手如何跨过这个坎的，我现在也是做java的第一个项目，也是做个下载器，是从两台不同的FTP服务器下载文件，支持断点，还要比较下载速度，显示下载了多少等，高手，请教啊 参考技术B 学java第一个项目就是下载器？~·······
·······你们老师蛮高看你们的昂····追问

此话何意？？呵呵

追答

这个···这个·········
···········开始学java不是叫你敲HAOLL WORED而是做下载器！···········
······················

追问

之前我们已经学了java的高级特性，包括反射机制，AWT，Swing，输入和输出处理，多态，继承，封装，数据结构，还桥helloworld吗老大？呵呵

追答

也许是你的项目让我误会了！·····你再看看你的题目·········
····················

JAVA用swing做个日历

JAVA作业，我比作业要求的多加了些功能，可以滚轮和键盘左右键翻页快捷键做的也许比较傻吧，监听到就直接doClick();沉迷JAVA,对于我这种以前只写过控制台程序的来说，图形界面真是打开了新世界

//MySwingCalendar.java
package test2;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.KeyEventPostProcessor;
import java.awt.KeyboardFocusManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.Calendar;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.border.BevelBorder;
import javax.swing.border.CompoundBorder;

public class MySwingCalendar extends JFrame
    /**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private Calendar calendar;
	private final static String week[]="日","一","二","三","四","五","六";
	private JLabel dayLable[][]=new JLabel[6][7],monthLable;
    
    private void initCalendar() 
    	calendar=Calendar.getInstance();
    	calendar.set(Calendar.DATE,0);
    
     
    private void initFrame() 
    	setIconImage(new ImageIcon("icon\\\\Calendar.gif").getImage());
    	setSize(500, 300);
    	getContentPane().setLayout(new BorderLayout());
    	setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    	setLocationRelativeTo(null);
    	addWindowListener(new WindowAdapter() 
			
			@Override
			public void windowOpened(WindowEvent e) 
				requestFocus();
			
			
		);
    
    
	public MySwingCalendar() 
		super("Calendar");
    	initCalendar();
    	initFrame();
    	JPanel northPanel=new JPanel(new FlowLayout(FlowLayout.CENTER));
    	JButton preMonth=new JButton("上月");
    	preMonth.addActionListener(new ActionListener() 
    		
    		@Override
    		public void actionPerformed(ActionEvent e) 
    			calendarAdd(-1);
    		
    	);
    	northPanel.add(preMonth);
    	JButton nextMonth=new JButton("下月");
    	nextMonth.addActionListener(new ActionListener() 
    		
    		@Override
    		public void actionPerformed(ActionEvent e) 
    			calendarAdd(1);
    		
    	);
    	northPanel.add(nextMonth);
    	getContentPane().add(northPanel,BorderLayout.NORTH);
    	
    	JPanel centerPanel=new JPanel(new GridLayout(7, 7,1,1));
    	centerPanel.setBorder(new BevelBorder(BevelBorder.LOWERED));
    	for(String s:week)
    	
    		JButton weekButton=new JButton(s);
    		weekButton.addActionListener(new ActionListener() 
				
				@Override
				public void actionPerformed(ActionEvent e) 
					requestFocus();
				
			);
    		centerPanel.add(weekButton);
    	
    	for(int i=0;i<6;i++)
    	
    		for(int j=0;j<7;j++)
    		
    			JPanel tempJpanel=new JPanel();
    			dayLable[i][j]=new JLabel();
    			//dayLable[i][j].enableInputMethods(true);
    			dayLable[i][j].setHorizontalAlignment(JLabel.CENTER);
    			if(j%2==0)tempJpanel.setBackground(Color.white);
    			else tempJpanel.setBackground(Color.lightGray);
    			tempJpanel.add(dayLable[i][j]);
    			centerPanel.add(tempJpanel);
    		
    	
    	getContentPane().add(centerPanel, BorderLayout.CENTER);
    	
    	JPanel southPanel=new JPanel(new FlowLayout(FlowLayout.CENTER));
    	monthLable=new JLabel();
    	southPanel.add(monthLable);
    	getContentPane().add(southPanel,BorderLayout.SOUTH);
    	updateCalendar();
    	KeyboardFocusManager.getCurrentKeyboardFocusManager().addKeyEventPostProcessor(new KeyEventPostProcessor() 

    		private long lastLeftPress=0;
    		private long lastRightPress=0;
    		
			@Override
			public boolean postProcessKeyEvent(KeyEvent e) 
				long currentTime=System.currentTimeMillis();
				if(e.getID() == KeyEvent.KEY_PRESSED)
				
					if (e.getKeyCode() == KeyEvent.VK_LEFT&¤tTime-lastLeftPress>100) 
					
						lastLeftPress = currentTime;
						preMonth.requestFocus();
						preMonth.doClick();
					 
					else if (e.getKeyCode() == KeyEvent.VK_RIGHT&¤tTime-lastRightPress>100) 
					
						lastRightPress = currentTime;
						nextMonth.requestFocus();
						nextMonth.doClick();
					
				
				return false;
			
		);
    	addMouseWheelListener(new MouseWheelListener() 
			
    		private long lastMove=0;
			@Override
			public void mouseWheelMoved(MouseWheelEvent e) 
				int wheelRotation=e.getWheelRotation();
				long currentTime=System.currentTimeMillis();
			    if(wheelRotation==-1&¤tTime-lastMove>70)
				
			    	lastMove=currentTime;
					preMonth.requestFocus();
					preMonth.doClick();
				 
			    else if(wheelRotation==1&¤tTime-lastMove>70)
				
			    	lastMove=currentTime;
			    	nextMonth.requestFocus();
			    	nextMonth.doClick();
				 
				
			
		);
    	
        setVisible(true);
	
    
    public String toString()
    	String s=calendar.get(Calendar.YEAR)+"年"+(calendar.get(Calendar.MONTH)+1)+"月\\n";
    	for(String i:week)
				s+="  "+i;
    	s+="\\n";
    	int day=calendar.get(Calendar.DAY_OF_WEEK)%7;
    	for(int i=0;i<day;i++)s+="    ";
    	int maxDay=calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
    	for(int i=1;i<=maxDay;i++)
    	
    		s+=String.format("%4d",i);
    		if(day==6)
    		
    			s+="\\n";
    			day=0;
    		
    		else day++;
    	
    	return s;
    
    
    private void updateCalendar() 
    	int i=0,j=calendar.get(Calendar.DAY_OF_WEEK)%7;;
    	int maxDay=calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
    	//System.out.println(this);
    	for(int k=0;k<j;k++)dayLable[0][k].setText("");
    	for(int k=1;k<=maxDay;k++)
    	
    		dayLable[i][j].setText(Integer.toString(k));
    		if(j==6)
    		
    			i++;
    			j=0;
    		
    		else j++;
    	
    	while(i<6)
    	
    		dayLable[i][j].setText("");
    		if(j==6)
    		
    			i++;
    			j=0;
    		
    		else j++;
    	
    	monthLable.setText("日历："+calendar.get(Calendar.YEAR)+"年"+(calendar.get(Calendar.MONTH)+1)+"月");
    
    
    public void calendarAdd(int delta)
    
    	calendar.add(Calendar.MONTH,delta);
    	updateCalendar();
    
    
    public static void main(String args[]) 
    	new MySwingCalendar();