重新理解对象参数的用法
最近一直在用Swing编程，碰到了一个问题，想的很长时间都没有解决，最终请教了高人一下：
问题是：父面板和子面板，父面板上有一个按钮，点击后弹出子面板，在子面板上填加相应的信息，最后把信息回传到父面板上，刚开始是这样设计：
if(e.getSource() == addArgsButton) {
HTTPWEBDetailsPane httpWebDetailsPane = new HTTPWEBDetailsPane();
argTemplItemList.addAll(httpWebDetailsPane.getArgTemplItemList());
}
HTTPWEBDetailsPane 是子面板，相应代码如下：
package com.mousedou.monitor.datashow.alarm.mainarea.schedule;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.border.Border;
import javax.swing.border.TitledBorder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import Common.Action;
import Common.ArgTempl;
import Common.ArgTemplItem;
import Common.ArgType;
import Common.AssertType;
import Common.CollectType;
import Common.Element;
import Common.ElementType;
import Common.MonitorStep;
import Common.OrgRawRule;
import Common.ProtocolType;
import Common.RawOperate;
import Common.RawPosition;
import Common.RespAssert;
import Common.RespExpression;
import Common.RespRaw;
import Config.application.AppInfo;
import Config.application.ApplicationGrp;
import Config.application.ServiceInstance;
import Config.parameter.ParameterDef;
import Scheduler.NoExistAction;
import Scheduler.NoExistArgTempl;
import com.mousedou.monitor.alarmAnlyze.temp.ConvertUtil;
import com.mousedou.monitor.datashow.alarm.ParaDefManager;
import com.mousedou.monitor.datashow.alarm.mainarea.TableModel;
import com.mousedou.monitor.datashow.receive.Client;
import com.mousedou.monitor.datashow.receive.OperatorClient;
public class HTTPWEBDetailsPane implements ActionListener{
private Logger log = LoggerFactory.getLogger(HTTPWEBDetailsPane.class);
// 添加应用组窗口
private JFrame frame;
//主面板
private JPanel pane;
private Client client;
//采集协议
private ProtocolType protocolType;
//参数模板
private ArgTempl argTempl;
//参数模板下拉框
private JComboBox argTemplCB;
//获得主机名
public JTextField hostNameField;
//获得端口号
public JTextField portField;
//获得路径
public JTextField pathField;
//获得方法名
public String methodName;
//ArgTemplItem列表，用来获取固定参数
private List<ArgTemplItem> argTemplItemList ;
public List<ArgTemplItem> getArgTemplItemList() {
return argTemplItemList;
}
//添加固定参数按钮
private JButton addArgsButton;
//取消
private JButton cancelButton;
private static final Dimension JLabel_size = new Dimension(60, 25);
private static final Dimension JTextField_size = new Dimension(110, 25);
private static final Dimension JButton_size = new Dimension(60, 25);
private static final Dimension JRadioButton_size = new Dimension(110, 25);
private static final Dimension JComboBox_size = new Dimension(140, 25);
//弹窗操作
public HTTPWEBDetailsPane(){
super();
pane = new JPanel(new BorderLayout());
this.client = OperatorClient.getClient();
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
frame = new JFrame();
init(frame.getContentPane());
frame.setTitle("HTTPWEBDetailsPane");
frame.setSize(280, 260);
frame.setLocation(400, 240);
frame.setVisible(true);
}
});
}
private void init(Container container) {
if (container instanceof JFrame) {
((JFrame) container).setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
initPane();
container.add(pane, BorderLayout.CENTER);
}
private void initPane(){
JPanel paneN = new JPanel();
paneN.setPreferredSize(new Dimension(975, 10));
paneN.setBackground(Color.WHITE);
pane.add(paneN, BorderLayout.NORTH);
JPanel paneS = new JPanel();
paneS.setPreferredSize(new Dimension(975, 15));
paneS.setBackground(Color.WHITE);
pane.add(paneS, BorderLayout.SOUTH);
JPanel paneE = new JPanel();
paneE.setPreferredSize(new Dimension(15, 580));
paneE.setBackground(Color.WHITE);
pane.add(paneE, BorderLayout.EAST);
JPanel paneW = new JPanel();
paneW.setPreferredSize(new Dimension(15, 580));
paneW.setBackground(Color.WHITE);
pane.add(paneW, BorderLayout.WEST);
JPanel paneC = new JPanel(new BorderLayout());
paneC.setBackground(Color.WHITE);
pane.add(paneC, BorderLayout.CENTER);
setPaneC(paneC);
}
private void setPaneC(JPanel paneC){
JPanel addArgsPane = new JPanel(new BorderLayout());
addArgsPane.setPreferredSize(new Dimension(280, 260));
JPanel addArgsPaneC = new JPanel(new GridLayout(4, 0));
JPanel addArgsPaneC1 = new JPanel(new FlowLayout(FlowLayout.LEADING));
addArgsPaneC1.add(getTitleLabel("主机名"));
addArgsPaneC1.add(getHostName());
addArgsPaneC.add(addArgsPaneC1);
JPanel addArgsPaneC2 = new JPanel(new FlowLayout(FlowLayout.LEADING));
addArgsPaneC2.add(getTitleLabel("端口号"));
addArgsPaneC2.add(getPort());
addArgsPaneC.add(addArgsPaneC2);
JPanel addArgsPaneC3 = new JPanel(new FlowLayout(FlowLayout.LEADING));
addArgsPaneC3.add(getTitleLabel("路径"));
addArgsPaneC3.add(getPath());
addArgsPaneC.add(addArgsPaneC3);
JPanel addArgsPaneC4 = new JPanel(new FlowLayout(FlowLayout.LEADING));
addArgsPaneC4.add(getTitleLabel("方法名"));
addArgsPaneC4.add(getMethodCB());
addArgsPaneC.add(addArgsPaneC4);
addArgsPane.add(addArgsPaneC);
JPanel addArgsPaneS = new JPanel(new FlowLayout());
addArgsPaneS.setPreferredSize(new Dimension(280, 40));
final JFrame addArgsPaneFrame = new JFrame();
addArgsPaneS.add(getArgsSaveButton(addArgsPaneFrame));
addArgsPaneS.add(new JLabel(" "));
addArgsPaneS.add(getArgsCancelButton(addArgsPaneFrame));
addArgsPane.add(addArgsPaneS, BorderLayout.SOUTH);
paneC.add(addArgsPane, BorderLayout.CENTER);
}
/**
* 获得名为name的标签 右对齐
* @param name
* @return
*/
public JLabel getTitleLabel(String name){
JLabel label = new JLabel(name, JLabel.TRAILING);
label.setPreferredSize(JLabel_size);
return label;
}
/**
* 获得主机名
*/
private JTextField getHostName() {
hostNameField = new JTextField();
hostNameField.setPreferredSize(JTextField_size);
return hostNameField;
}
/**
* 获得端口号
*/
private JTextField getPort() {
portField = new JTextField();
portField.setPreferredSize(JTextField_size);
return portField;
}
/**
* 获得路径
*/
private JTextField getPath() {
pathField = new JTextField();
pathField.setPreferredSize(JTextField_size);
return pathField;
}
/**
* 获得方法名下拉框
*/
private JComboBox getMethodCB() {
JComboBox methodCB = new JComboBox();
methodCB.addItem(" ");
methodCB.addItem("GET");
methodCB.addItem("POST");
methodCB.addItemListener(new ItemListener() {
@Override
public void itemStateChanged(ItemEvent e) {
String s = (String)e.getItem();
if(!s.equals(" ")){
methodName = s;
}else{
methodName = null;
}
}
});
return methodCB;
}
/**
* 固定参数保存按钮
* @param frame
* @return
*/
private JButton getArgsSaveButton(final JFrame frame){
addArgsButton = new JButton("保存");
addArgsButton.setPreferredSize(JButton_size);
addArgsButton.addActionListener(this);
return addArgsButton;
}
/**
* 取消按钮
* @param frame
* @return
*/
private JButton getArgsCancelButton(final JFrame frame){
cancelButton = new JButton("取消");
cancelButton.setPreferredSize(JButton_size);
cancelButton.addActionListener(this);
return cancelButton;
}
@Override
public void actionPerformed(ActionEvent e) {
if(e.getSource() == addArgsButton) {
String hostnameTemp = hostNameField.getText();
String portTemp = portField.getText();
String pathTemp = pathField.getText();
String methodNameTemp = methodName;
if(hostnameTemp == null || "".equals(hostnameTemp)){
JOptionPane.showMessageDialog(null, "请填写主机名！", "警告", JOptionPane.WARNING_MESSAGE);
}else if(portTemp == null || "".equals(portTemp)){
JOptionPane.showMessageDialog(null, "请填写端口号！", "警告", JOptionPane.WARNING_MESSAGE);
}else if(pathTemp == null || "".equals(pathTemp)){
JOptionPane.showMessageDialog(null, "请填写路径！", "警告", JOptionPane.WARNING_MESSAGE);
}else if(methodNameTemp == null || "".equals(methodNameTemp)){
JOptionPane.showMessageDialog(null, "请选择参数名称！", "警告", JOptionPane.WARNING_MESSAGE);
} else{
List<ArgTemplItem> argItemList = new ArrayList<ArgTemplItem>();
ArgTemplItem argTemplItem1 = new ArgTemplItem("hostname", "主机名", hostnameTemp.getBytes(), ConvertUtil.encodeArgType("String"), ".*", "访问的主机名");
ArgTemplItem argTemplItem2 = new ArgTemplItem("port", "访问端口", portTemp.getBytes(), ConvertUtil.encodeArgType("int"), ".*", "访问的端口，默认为80");
ArgTemplItem argTemplItem3 = new ArgTemplItem("path", "访问路径", pathTemp.getBytes(), ConvertUtil.encodeArgType("String"), ".*", "访问的文件名或路径");
ArgTemplItem argTemplItem4 = new ArgTemplItem("methodName", "访问方法", methodNameTemp.getBytes(), ConvertUtil.encodeArgType("String"), ".*", "使用的方法“GET”或“POST”");
argItemList.add(argTemplItem1);
argItemList.add(argTemplItem2);
argItemList.add(argTemplItem3);
argItemList.add(argTemplItem4);
argTemplItemList.addAll(argItemList);
frame.dispose();
}
} else if(e.getSource() == cancelButton) {
frame.dispose();
}
}
public JPanel getHTTPWEBDetailsPane(){
return pane;
}
public static void main(String[] args){
SwingUtilities.invokeLater(new Runnable(){
@Override
public void run() {
JFrame frame = new JFrame("HTTPWEBDetailsPane");
HTTPWEBDetailsPane details = new HTTPWEBDetailsPane(null);
frame.getContentPane().add(details.getHTTPWEBDetailsPane());
frame.setSize(280, 260);
frame.setLocation(400, 240);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
});
}
}
正确的流程应该是弹出子面板后保存相应的数据到argTemplItemList，然后在父面板中调用子面板对象的getArgTemplItemList()方法，整好可以解决问题，就是上面第一段代码：
HTTPWEBDetailsPane httpWebDetailsPane = new HTTPWEBDetailsPane(); argTemplItemList.addAll(httpWebDetailsPane.getArgTemplItemList());
可实际上完全不是那么回事，因为这是两个线程，父面板是一个线程，子面板也是一个线程，调用子面板的同时父面板线程会继续运行下去，执行这一句代码：
httpWebDetailsPane.getArgTemplItemList();
这时候得到的ArgTemplItemList当然是空的了。
解决方案其实也很简单，就是把父面板中argTemplItemList作为子面板的参数传给子面板，再为子面板设计一个有参的构造方法，这样在子面板对这个参数做的改动就会自动反应到父面板上来。
正确的几外关键代码如下：
父面板中：
if("HTTP".equals(decodeProtocolType(protocolType))) {
HTTPWEBDetailsPane httpWebDetailsPane = new HTTPWEBDetailsPane(argTemplItemList);
}
子面板中：
//ArgTemplItem列表，用来获取固定参数
private List<ArgTemplItem> argTemplItemList ;
//有参的构造参数
public HTTPWEBDetailsPane(List<ArgTemplItem> argTemplItemList){
super();
this.argTemplItemList=argTemplItemList;
pane = new JPanel(new BorderLayout());
this.client = OperatorClient.getClient();
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
frame = new JFrame();
init(frame.getContentPane());
frame.setTitle("HTTPWEBDetailsPane");
frame.setSize(280, 260);
frame.setLocation(400, 240);
frame.setVisible(true);
}
});
}
原理其实很简单，对象参数的用法，唉，基础真的很重要啊！