java - 自定义文档过滤器 - "Invalid remove"异常

Question

我创建了自己的 DocumentFormat，即用分号分隔的整数列表。解析字符串等工作正常，但是当我想用新字符串替换整个文本时会出现问题。

调用 super.replace(fb, 0, out.length(), out, attrs); 时出现异常无效删除。谁能解释一下这条消息吗？

这是我的类(class)代码:

import java.util.ArrayList;

import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
import javax.swing.text.DocumentFilter;

public class IntsFilter extends DocumentFilter {

        @Override
       public void insertString(FilterBypass fb, int offset, String string,
             AttributeSet attr) throws BadLocationException {
            // Do nothing so far
       }

       @Override
       public void replace(FilterBypass fb, int offset, int length, String text,
             AttributeSet attrs) throws BadLocationException {

           Boolean test = false;

           try {
               Integer.parseInt(text);
               test = true;
           } catch (NumberFormatException e) {
               test = text.equals(";");
           }

            if (!test) return;

            Document doc = fb.getDocument();
            StringBuilder sb = new StringBuilder();
            sb.append(doc.getText(0, doc.getLength()));
            sb.replace(offset, offset + length, text);

            ArrayList<String> data = toArray(sb.toString());
            System.out.println(arrayToString(data));
            String out = arrayToString(data);

            try {
                super.replace(fb, 0, out.length(), out, attrs);
            } catch (Exception e) {
                System.out.println(e.getMessage());
            }

       }

       @Override
       public void remove(FilterBypass fb, int offset, int length)
             throws BadLocationException {

           try {
               super.remove(fb, offset, length);
            } catch (Exception e) {
                System.out.println(e.getMessage());
            }
          // TODO: uzupełnić

       }

       protected String arrayToString(ArrayList<String> input) {

           String result = "";

           for (int i=0; i<input.size(); i++) {

               if (i == input.size() - 1)
                   result += input.get(i).equals("0") ? "" : input.get(i);
               else
                   result += input.get(i) + "; ";

           }

           return result;

       }

       protected ArrayList<String> toArray(String input) {

           input = input.replaceAll(";$", "; 0");

           ArrayList<String> list = new ArrayList<String>();

           for (String part : input.replaceAll("\\s", "").split(";")) {
               try {
                   Integer.parseInt(part);
                   list.add(part);
               } catch (NumberFormatException e) {}
           }

           return list;

       }

}

Answer 1

如果偏移量+长度大于文档的当前长度，则会发生该错误。请勿自行更换。让父类(super class)来做吧。将 super.replace() 调用移至测试之后。