救救我的记事本啊！
我用ＪＡＶＡ写了个简单的记事本大家谁能说说怎么判断JTextArea中的内容是否发生了改变呢

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change事件
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添加一个ActionListener
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The java.awt.TextArea could be monitored for changes by adding a TextListener for TextEvents. In the JTextComponent based components, changes are broadcasted from the model via a DocumentEvent to DocumentListeners. The DocumentEvent gives the location of the change and the kind of change if desired. The code fragment might look something like:

DocumentListener myListener = ??;
JTextArea myArea = ??;
myArea.getDocument().addDocumentListener(myListener);

api 原文

http://java.sun.com/j2se/1.5.0/docs/api/javax/swing/JTextArea.html
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增加定时自动保存
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JTextArea的父类（应该是JTextComponent如果没记错的话）直接有copy(),cut(),paste()