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我有一個ArrayList需要從我的GUI的多個組件讀取和寫入。我在下面這個簡潔的代碼段中大幅減少了代碼量來說明問題。如何同步對多線程訪問的數組列表的訪問？
父框架可能有許多內部框架，每個內部框架都需要它自己的此ArrayList實例。但是，特定內部框架的所有子組件都需要訪問此ArrayList的相同實例，以便在特定內部框架的一個真實ArrayList中保留添加和刪除操作。對於這個例子，ArrayList中的所有數據都需要在內存中。但是，稍後我將添加代碼以每次在內存中進行更改時更新持久性數據文件。
這是我縮小的代碼段。任何人都可以告訴我如何更改此代碼，以便它能夠提供我所需的讀/寫訪問權限？此外，任何有關文章的鏈接將不勝感激。
ParentFrame.java：
package testGlobalArrayList;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Panel;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JLabel;
import javax.swing.JLayeredPane;
import javax.swing.JTabbedPane;
import java.util.*;
public class ParentFrame extends JFrame{
private static final long serialVersionUID = 1L;
JLayeredPane desktop;
JInternalFrame internalFrame;
public ParentFrame() {
super("parent frame");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setPreferredSize(new Dimension(600, 300));
Panel p = new Panel();
this.add(p, BorderLayout.SOUTH);
desktop = new JDesktopPane();
this.add(desktop, BorderLayout.CENTER);
this.pack();
this.setSize(new Dimension(600, 300));
this.setLocationRelativeTo(null);
final int DELTA = 40;
int offset = DELTA;
int ifWidth = 400;
int ifHeight = 200;
internalFrame = new JInternalFrame("internal frame", true, true, true, true);
internalFrame.setLocation(offset, offset);
offset += DELTA;
JTabbedPane jtp = createTabbedPane();
internalFrame.add(jtp);
// want to make this ArrayList read/write accessible to every GUI component below this level
ArrayList<Integer> myArrayList= new ArrayList<Integer>();
myArrayList.add(8);
myArrayList.add(6);
myArrayList.add(7);
desktop.add(internalFrame);
internalFrame.pack();
internalFrame.setSize(new Dimension(ifWidth,ifHeight));
internalFrame.setVisible(true);
}
private JTabbedPane createTabbedPane() {
JTabbedPane jtp = new JTabbedPane();
jtp.setMinimumSize(new Dimension(600,300));
createTab(jtp, "Tab1");
createTab(jtp, "Tab2");
return jtp;
}
private void createTab(JTabbedPane jtp, String s) {
if(s=="Tab1"){
TestGUI myTimeSeriesGUI = new TestGUI();
jtp.add(s,myTimeSeriesGUI);
}
else{jtp.add(s, new JLabel("TabbedPane " + s, JLabel.CENTER));}
}
public static void main(String args[]) {
ParentFrame myParentFrame = new ParentFrame();
myParentFrame.setVisible(true);
}
}
TestGUI.java：
package testGlobalArrayList;
import javax.swing.JPanel;
import java.awt.BorderLayout;
import java.util.ArrayList;
import javax.swing.Box;
public class TestGUI extends JPanel{
TestGUI(){
Box verticalBox = Box.createVerticalBox();
verticalBox.add(new TestPanel());
verticalBox.add(new TestPanel());
verticalBox.add(new TestPanel());
this.add(verticalBox, BorderLayout.CENTER);
}
void anotherMethod(){
// want to be able to add or delete records to same ArrayList here
myArrayList.add(5);
myArrayList.add(3);
myArrayList.add(0);
myArrayList.add(9);
}
}
TestPanel.java：
package testGlobalArrayList;
import java.awt.Color;
import java.util.Random;
import javax.swing.JPanel;
import javax.swing.border.EtchedBorder;
public class TestPanel extends JPanel {
public TestPanel(){
this.setBackground(getRandomColor());
this.setBorder(new EtchedBorder());
this.setSize(150,20);
}
void anotherMethod(){
//want to be able to add or delete records from same ArrayList here
myArrayList.remove(1);
myArrayList.remove(2);
myArrayList.remove(3);
}
private static Color getRandomColor(){
Random rand = new Random();
float r = rand.nextFloat();
float g = rand.nextFloat();
float b = rand.nextFloat();
Color randomColor = new Color(r, g, b);
return randomColor;
}
}
不要* if（s ==「Tab1」）*，請使用* .equals（）*。 – JimmyB
@HannoBinder +1它在這裏只能正常工作，因爲字符串文字是被執行的 –