java 对象序列化实现复杂UI对象状态的保存。

有时我们在遇到要对复杂对象的状态进行保存时，常常难以处理对象的状态。比如如图所示遇到的情况：

我们要在点击OK按钮时要保存该界面的状态，而在点击Cancel按钮时要取消该次界面的操作，回到之前界面的状态。如果在点击Cancel状态时，该界面的数据状态和初始化一致，则下次我们弹出该对话框时，直接重新初始化该对话框就对了。可是如果之前我们已经对该界面进行了操作。要在点击Cancel后，再次显示该对话框时能回到上次的状态，就比较麻烦了。我们可以对该界面的各个组件的状态进行记录保存，在初始化完该对话框后，根据保存的状态再来填充界面的状态，这能达到我们的要求。可是如果该界面的数据结构比较复杂，这样做就比较麻烦了。下面我们采用java对象序列化对象来实现复杂数据结构状态的保存。

示例

复杂对象代码：

package com.michael.test;import java.awt.BorderLayout;import java.awt.Dimension;import java.awt.FlowLayout;import java.awt.GridLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.io.Serializable;import javax.swing.JButton;import javax.swing.JCheckBox;import javax.swing.JComboBox;import javax.swing.JDialog;import javax.swing.JPanel;import javax.swing.JRadioButton;/** *@author mengke *@email [e-mail] *@version 1.0 *@date  2011-11-5 下午06:41:39 */public class ComplexObject extends JDialog implements Serializable{private static final long serialVersionUID = 1L;    private JButton btnOk;    private JButton btnCancel;    private JComboBox comBox;    private JRadioButton radioBtn;    private JRadioButton radioBtn2;    private JCheckBox checkBox;    private JCheckBox checkBox2;    private boolean isBtnOkAction;    public ComplexObject(){putcompents();setSize(new Dimension(200,300));setModal(true);}private void putcompents() {comBox = new JComboBox();comBox.addItem("item1");comBox.addItem("item2");radioBtn = new JRadioButton("radio button1");radioBtn2 = new JRadioButton("radio button2");checkBox = new JCheckBox("check box 1");checkBox2 = new JCheckBox("check box 2");JPanel _plBody = new JPanel();_plBody.setLayout(new GridLayout(5, 1));_plBody.add(comBox);_plBody.add(radioBtn);_plBody.add(radioBtn2);_plBody.add(checkBox);_plBody.add(checkBox2);btnOk = new JButton("OK");btnCancel = new JButton("Cancel");ButtonActionListener _actionListener = new ButtonActionListener();btnOk.addActionListener(_actionListener);btnCancel.addActionListener(_actionListener);JPanel _plButton = new JPanel();_plButton.setLayout(new FlowLayout(FlowLayout.RIGHT, 5, 5));_plButton.add(btnOk);_plButton.add(btnCancel);setLayout(new BorderLayout());add(_plBody,BorderLayout.CENTER);add(_plButton,BorderLayout.SOUTH);}public boolean isBtnOkAction(){return isBtnOkAction;}

 

       /**该类必须实现Serializable接口，不然监听类不会被序列化*/    class ButtonActionListener implements ActionListener,Serializable{@Overridepublic void actionPerformed(ActionEvent e) {if(e.getSource() == btnOk){isBtnOkAction = true;setVisible(false);}else if(e.getSource() == btnCancel){isBtnOkAction = false;setVisible(false);}}}}

拥有该复杂对象的类：

package com.michael.test;import java.awt.BorderLayout;import java.awt.Dimension;import java.awt.FlowLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JPanel;/** * 复杂对象状态的保持 *  * @author mengke *@email [e-mail] *@version 1.0 *@date 2011-11-5 下午06:39:12 */public class ComplexStatusSave {private ComplexObject currentComplexObj;private ComplexObject oldComplexObj;private boolean isPreSaveOkStatus;public void showUI() {final JFrame _frame = new JFrame();_frame.setLayout(new BorderLayout());JButton _btnAction = new JButton("button");_btnAction.addActionListener(new ActionListener() {@Overridepublic void actionPerformed(ActionEvent e) {if (currentComplexObj == null ||oldComplexObj == null|| !isPreSaveOkStatus) {currentComplexObj = new ComplexObject( );currentComplexObj.setLocationRelativeTo(_frame);}currentComplexObj.setVisible(true);//操作前没有保存OK状态，则重新获取是否需要保存OK状态if (!isPreSaveOkStatus) {//如果点击了OK按钮则保存OK状态if(currentComplexObj.isBtnOkAction()){oldComplexObj = copyObject(currentComplexObj);isPreSaveOkStatus = true;}}else if(!currentComplexObj.isBtnOkAction()){currentComplexObj = oldComplexObj;oldComplexObj = copyObject(currentComplexObj);} else if (currentComplexObj.isBtnOkAction()) {oldComplexObj = copyObject(currentComplexObj);}}});JPanel _plButton = new JPanel();_plButton.setLayout(new FlowLayout());_plButton.add(_btnAction);_frame.add(_plButton, BorderLayout.SOUTH);_frame.setSize(new Dimension(300, 200));_frame.setLocation(300, 200);_frame.setVisible(true);}/** * 对对象进行复制 * @param obj * @return */private ComplexObject copyObject(Object obj) {ByteArrayOutputStream baos = new ByteArrayOutputStream();try {ObjectOutputStream oops = new ObjectOutputStream(baos);oops.writeObject(obj);oops.close();} catch (IOException e) {e.printStackTrace();return null;}ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());try {ObjectInputStream ois = new ObjectInputStream(bais);return (ComplexObject) ois.readObject();} catch (IOException e) {e.printStackTrace();return null;} catch (ClassNotFoundException e) {e.printStackTrace();return null;}}public static void main(String[] args) {new ComplexStatusSave().showUI();}}

对于复杂对象数据状态的保存，这里难就难再有两个按钮，不同的按钮的操作要求有不同的结果。我们这里只是通过java对象序列化来实现对复杂UI对象进行一份拷贝，保存一份历史状态的备份。