我可以识别Java中放置光标的字符串吗？

Question

目前，我正在研究Java项目。但是要做到这一点，我想从游标中读取字符串，即我想读取当前放置游标的字符串。我该怎么办？

Answer 1

尚不清楚您将文本插入标记（光标）放置在的确切位置。下面的示例方法假定光标位于Swing文本组件（如JTextField，JTextArea，JEditPane等中显示的文本中包含的单词上，在< [拥有应用程序项目。 javax.swing.text.Utilities类可以获取所需的数据。

public static String getWordAtCaret(JTextComponent tc) {
    String res = null;
    try {
        int caretPosition = tc.getCaretPosition();
        int startIndex = Utilities.getWordStart(tc, caretPosition);
        int endIndex = Utilities.getWordEnd(tc, caretPosition);
        res = tc.getText(startIndex, endIndex - startIndex);
    }
    catch (BadLocationException ex) {
        // Purposely Ignore so as to return null.
        // Do what you want with the exception if you like.
    }
    return res;
}

public static String getNextWordFromCaret(JTextComponent tc) {
    String res = null;
    try {
        int caretPosition = Utilities.getNextWord(tc, tc.getCaretPosition());
        int startIndex = Utilities.getWordStart(tc, caretPosition);
        int endIndex = Utilities.getWordEnd(tc, caretPosition);
        res = tc.getText(startIndex, endIndex - startIndex);
    }
    catch (BadLocationException ex) {
        // Purposely Ignore so as to return null.
        // Do what you want with the exception if you like.
    }
    return res;
}

public static String getPreviousWordFromCaret(JTextComponent tc) {
    String res = null;
    try {
        int caretPosition = Utilities.getPreviousWord(tc, tc.getCaretPosition()) - 2;
        int startIndex = Utilities.getWordStart(tc, caretPosition);
        int endIndex = Utilities.getWordEnd(tc, caretPosition);
        res = tc.getText(startIndex, endIndex - startIndex);
    }
    catch (BadLocationException ex) {
        // Purposely Ignore so as to return null.
        // Do what you want with the exception if you like.
    }
    return res;
}

注：

使用getNextWordFromCaret（）或getPreviousWordFromCaret（）方法时，附加到特定单词的标点符号可能会提供意外的结果。可以使用这两种方法将标点符号如句点（。）视为一个单词，因此必须考虑一些防止这种现象的出现。