Question

我正在使用JTextPane从网络应用程序记录一些数据，并且在程序运行大约10个多小时后，我得到了内存堆错误。文本继续添加到JTextPane，这会不断增加内存使用量。反正我是否可以使JTextPane像命令提示符窗口一样？当新文本出现时我应该摆脱旧文本吗？这是我用来写入JTextPane的方法。

volatile JTextPane textPane = new JTextPane();
public void println(String str, Color color) throws Exception
{
    str = str + "\n";
    StyledDocument doc = textPane.getStyledDocument();
    Style style = textPane.addStyle("I'm a Style", null);
    StyleConstants.setForeground(style, color);
    doc.insertString(doc.getLength(), str, style);
}

Answer 1

一旦长度超过某个限制，您可以从StyledDocument的开头删除等值的数量：

int docLengthMaximum = 10000;
if(doc.getLength() + str.length() > docLengthMaximum) {
    doc.remove(0, str.length());
}
doc.insertString(doc.getLength(), str, style);

Answer 2

您需要利用Documents DocumentFilter

public class SizeFilter extends DocumentFilter {

    private int maxCharacters;
    public SizeFilter(int maxChars) {
        maxCharacters = maxChars;
    }

    public void insertString(FilterBypass fb, int offs, String str, AttributeSet a)
        throws BadLocationException {
        if ((fb.getDocument().getLength() + str.length()) > maxCharacters)
            int trim = maxCharacters - (fb.getDocument().getLength() + str.length()); //trim only those characters we need to
            fb.remove(0, trim);
        }
        super.insertString(fb, offs, str, a);
    }

    public void replace(FilterBypass fb, int offs, int length, String str, AttributeSet a)
        throws BadLocationException {

        if ((fb.getDocument().getLength() + str.length() - length) > maxCharacters) {
            int trim = maxCharacters - (fb.getDocument().getLength() + str.length() - length); // trim only those characters we need to
            fb.remove(0, trim);
        }
        super.replace(fb, offs, length, str, a);
    }
}

基于http://www.jroller.com/dpmihai/entry/documentfilter

的字符限制器过滤器

您需要将其应用于文本区域Text组件，因此......

((AbstractDocument)field.getDocument()).setDocumentFilter(...)

限制JTextPane空间使用

2 个答案: