java监视系统内存状态小程序

迷南。 2022-03-30 10:20 202阅读 0赞

动态显示了当前机器内存的使用情况，并且不断刷新空闲内存所占比例，程序运行的结果如下图所示：

[![java监视系统内存状态小程序][java]][java_java]

主要应用：

（1）多线程的使用

（2）getRuntime()方法的使用

程序源代码如下：

MainFrame.java

package jmemorydemo;

import java.awt.\*;  
import java.awt.event.\*;

import javax.swing.\*;

public class MainFrame extends JFrame\{  
   
 private JPanel contentPane;  
 private BorderLayout borderLayout1 = new BorderLayout();  
 private JProgressBar jProgressBar1 = new JProgressBar();  
 private JLabel jLabel1 = new JLabel();  
 private JLabel jLabel2 = new JLabel();  
   
 //构造方法  
 public MainFrame()\{  
  enableEvents(AWTEvent.WINDOW\_EVENT\_MASK);  
  try\{  
   jbInit();  
  \}catch(Exception e)\{  
   e.printStackTrace();  
  \}  
 \}  
   
 public void jbInit()throws Exception\{  
  contentPane = (JPanel)this.getContentPane();  
  contentPane.setLayout(borderLayout1);  
  this.setSize(new Dimension(304,215));  
  this.setTitle("内存监视演示");  
  jLabel1.setFont(new java.awt.Font("Dialog", 0, 14));  
  jLabel1.setHorizontalAlignment(SwingConstants.CENTER);  
  jLabel1.setText("Memory Monitor");  
  //将进度设置成垂直状态  
  jProgressBar1.setOrientation(JProgressBar.VERTICAL);  
  jProgressBar1.setFont(new java.awt.Font("Dialog",0,14));  
  jProgressBar1.setToolTipText("");  
  //设置进度条能够显示字符串文本  
  jProgressBar1.setStringPainted(true);  
    
  jLabel2.setFont(new java.awt.Font("Dialog", 0, 14));  
  jLabel2.setText("");  
  contentPane.add(jProgressBar1, BorderLayout.CENTER);  
  contentPane.add(jLabel1, BorderLayout.NORTH);  
  contentPane.add(jLabel2, BorderLayout.SOUTH);  
  //调用类ProgressThread  
  ProgressThread pThread = new ProgressThread(this.jProgressBar1, this.jLabel2);  
  pThread.start();    
 \}  
   
 //覆盖方法processWindowEvent(WindowEvent e),当窗口关闭时，程序能够正常结束  
 public void processWindowEvent(WindowEvent e)\{  
  super.processWindowEvent(e);  
  if(e.getID() == WindowEvent.WINDOW\_CLOSED)\{  
   System.exit(0);  
  \}  
 \}  
\}  
ProgressThread.java

package jmemorydemo;

import javax.swing.\*;

public class ProgressThread extends Thread\{  
   
 JProgressBar pBar;//进度条  
 JLabel label;//标签  
 public ProgressThread(JProgressBar pBar, JLabel label)\{  
  this.pBar = pBar;  
  this.label = label;  
 \}  
   
 public void run()\{  
  int min = 0;  
  int max = 100;  
  int free = 0;  
  int totle = 0;  
  int status = 0;  
  pBar.setMinimum(min);//设置进度条的最小长度为0  
  pBar.setMaximum(max);//设置进度条的最大长度为100  
  pBar.setValue(status);//设置进度条的当前的值  
  while(true)\{  
   try\{  
    //获取内存的总内存数  
    totle = (int)(Runtime.getRuntime().totalMemory()/1024);  
    //获取空闲的内存数  
    free = (int)(Runtime.getRuntime().freeMemory()/1024);  
   \}catch(Exception e)\{  
    e.printStackTrace();  
   \}  
   //设置标签的显示文本内容  
   label.setText("Free Memory: " + (int)(Runtime.getRuntime().freeMemory()/1024) + "K"  
                           + " Totle Memory Allocated: "  
                           + (int)(Runtime.getRuntime().totalMemory()/1024) + "K");  
   status = (int)(free \* 100 / totle);  
   pBar.setValue(status);  
   //设置进度条内容  
   pBar.setString("Free Memory " + status + "%");  
   try\{  
    Thread.sleep(1000);  
   \}catch(InterruptedException err)\{  
    err.printStackTrace();  
   \}  
  \}  
 \}

JmemoryDemo.java

package jmemorydemo;

import java.awt.\*;

public class JMemoryDemo \{  
 private boolean packFrame = false;  
 //构造方法  
 public JMemoryDemo()\{  
  MainFrame frame = new MainFrame();  
  //校验frame的预设值  
  if(packFrame)\{  
   frame.pack();  
  \}else\{  
   frame.validate();  
  \}  
  //让主窗口启动后位于屏幕的中央  
  //去的屏幕的长度和宽度  
  Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();  
  //取得当前frame的长度和宽度  
  Dimension frameSize = frame.getSize();  
  if(frameSize.height > screenSize.height)frameSize.height = screenSize.height;  
  if(frameSize.width > screenSize.width)frameSize.width = screenSize.width;  
  //设置frame显示的位置  
  frame.setLocation((screenSize.width - frameSize.width)/2,  
              (screenSize.height - frameSize.height)/2);  
  frame.setVisible(true);    
 \}  
   
 public static void main(String\[\] args)\{  
  new JMemoryDemo();  
 \}

[java]: http://s6.sinaimg.cn/bmiddle/5d51780d45e05177494e5
[java_java]: /images/20220330/c0d37ceab0134de2816f3ce4dfc03a70.png