[英]Populating a JList from a JButton ActionListener
按下按鈕后嘗試填充JList時遇到很多問題。 下面的代碼利用了我之前成功采用的一種技術,但是我無法使它正常工作。 目標是在按下按鈕后運行測試,並在單獨的JList中顯示通過的URL和失敗的URL。
動作監聽器:
//Start button--starts tests when pressed.
JButton start = new JButton("Start");
start.setPreferredSize(new Dimension(400, 40));
start.setAlignmentX(Component.CENTER_ALIGNMENT);
start.addActionListener(new Web(urlA, codeA, cb, passJ, failJ));
panel2.add(start);
動作偵聽器方法:
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;
import java.util.ArrayList;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JList;
public class Web implements ActionListener {
private ArrayList<String> urls;
private ArrayList<Integer> statusCodes;
private JComboBox cb;
private JList passJ = new JList();
private JList failJ = new JList();
//constructor--allows other values to be used
public Web(ArrayList<String> urls, ArrayList<Integer> statusCodes, JComboBox cb, JList passList, JList failList ){
this.urls = urls;
this.statusCodes = statusCodes;
this.cb = cb;
this.passJ = passJ;
this.failJ = failJ;
}
@Override
public void actionPerformed(ActionEvent event){
ArrayList<String> resultsP = new ArrayList<String>();
ArrayList<String> resultsF = new ArrayList<String>();
//get source
JButton start = (JButton) event.getSource();
//get value from combobox
String selected = cb.getSelectedItem().toString();
if(selected.equals("ALL")){
}
if(selected.equals("STATUS CODE")){
for(int i = 0; i < urls.size(); i++){
try {
URL u = new URL(urls.get(i));
HttpURLConnection connection = (HttpURLConnection)u.openConnection(); //open connection and cast to HttpURLConnection
connection.setRequestMethod("GET");
connection.connect();
int code = connection.getResponseCode();
if (code == statusCodes.get(i)){
System.out.println(i + "."+ urls.get(i)+" \t\t\t PASS");
resultsP.add(urls.get(i));
}
else{
System.out.println(i + "." +urls.get(i)+ "\t\t\t FAIL");
resultsF.add(urls.get(i));
}
} catch (MalformedURLException | ProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
for (String str: resultsP){
System.out.println(str);
}
System.out.println("/////////////////////////////////////////////////////////////////////////////////");
for (String str: resultsF){
System.out.println(str);
}
passJ.removeAll();
failJ.removeAll();
passJ.setListData(resultsP.toArray());
failJ.setListData(resultsF.toArray()) ;
passJ.repaint();
failJ.repaint();
}//StatusCodeTest
}
}
列表如何添加到GUI:
JList passJ = new JList(urlA.toArray());
JScrollPane scroll1 = new JScrollPane(passJ);
scroll1.setPreferredSize(new Dimension (700, 150));
scroll1.setMaximumSize( scroll1.getPreferredSize() );
scroll1.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED);
panel2.add(scroll1);
panel2.add(Box.createRigidArea(new Dimension(0,50)));
JList failJ = new JList(urlA.toArray());
JScrollPane scroll2 = new JScrollPane(failJ);
scroll2.setPreferredSize(new Dimension(700, 150));
scroll2.setMaximumSize(scroll1.getPreferredSize());
scroll2.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED);
panel2.add(scroll2);
//spacer
panel2.add(Box.createRigidArea(new Dimension(0,25)));
任何GUI舞將不勝感激。
Web
類和GUI
類中具有不同的passJ
/ failJ
實例。 passJ.removeAll(); failJ.removeAll();
不會清除Container
的JList
項。 這是向JList
添加/清除項目的簡單示例:
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class TestFrame extends JFrame {
private JList<Integer> normal;
private JList<Integer> fail;
private Integer[] vals;
public TestFrame() {
init();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
pack();
setLocationRelativeTo(null);
setVisible(true);
}
private void init() {
normal = new JList<Integer>(new DefaultListModel<Integer>());
fail = new JList<Integer>(new DefaultListModel<Integer>());
vals = new Integer[]{1,2,3,4,5,6,7,8,9,33};
JButton add = new JButton("collect data");
add.addActionListener(getCollectListener());
JButton clear = new JButton("clear data");
clear.addActionListener(getClearListener());
JPanel p = new JPanel();
p.add(new JScrollPane(normal));
p.add(new JScrollPane(fail));
JPanel btnPanel = new JPanel();
btnPanel.add(add);
btnPanel.add(clear);
add(p);
add(btnPanel,BorderLayout.SOUTH);
}
private ActionListener getClearListener() {
return new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
((DefaultListModel<Integer>)normal.getModel()).removeAllElements();
((DefaultListModel<Integer>)fail.getModel()).removeAllElements();
}
};
}
private ActionListener getCollectListener() {
return new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
for(Integer i : vals){
if(i%3==0){
((DefaultListModel<Integer>)normal.getModel()).addElement(i);
} else {
((DefaultListModel<Integer>)fail.getModel()).addElement(i);
}
}
}
};
}
public static void main(String args[]) {
new TestFrame();
}
}
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