Java Swing之StyledDocument的合并

http://blog.fyent.net/2011/01/java_swing_merge_styleddocument/

    public void mergeDocument(DefaultStyledDocument source,
            DefaultStyledDocument dest) throws BadLocationException {
        ArrayList specs = new ArrayList();
        DefaultStyledDocument.ElementSpec spec = new DefaultStyledDocument.ElementSpec(
                new SimpleAttributeSet(),
                DefaultStyledDocument.ElementSpec.EndTagType);
        specs.add(spec);
        fillSpecs(source.getDefaultRootElement(), specs, false);
        spec = new DefaultStyledDocument.ElementSpec(new SimpleAttributeSet(),
                DefaultStyledDocument.ElementSpec.StartTagType);
        specs.add(spec);

        DefaultStyledDocument.ElementSpec[] arr = new DefaultStyledDocument.ElementSpec[specs
                .size()];
        specs.toArray(arr);
        insertSpecs(dest, dest.getLength(), arr);
    }

    protected void insertSpecs(DefaultStyledDocument doc, int offset,
            DefaultStyledDocument.ElementSpec[] specs) {
        try {
            // doc.insert(0, specs); method is protected so we have to
            // extend document or use such a hack
            Method m = DefaultStyledDocument.class.getDeclaredMethod("insert",
                    new Class[] { int.class,
                            DefaultStyledDocument.ElementSpec[].class });
            m.setAccessible(true);
            m.invoke(doc, new Object[] { offset, specs });
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    protected void fillSpecs(Element elem, ArrayList specs, boolean includeRoot)
            throws BadLocationException {
        DefaultStyledDocument.ElementSpec spec;
        if (elem.isLeaf()) {
            String str = elem.getDocument().getText(elem.getStartOffset(),
                    elem.getEndOffset() - elem.getStartOffset());
            spec = new DefaultStyledDocument.ElementSpec(elem.getAttributes(),
                    DefaultStyledDocument.ElementSpec.ContentType, str
                            .toCharArray(), 0, str.length());
            specs.add(spec);
        } else {
            if (includeRoot) {
                spec = new DefaultStyledDocument.ElementSpec(elem
                        .getAttributes(),
                        DefaultStyledDocument.ElementSpec.StartTagType);
                specs.add(spec);
            }
            for (int i = 0; i < elem.getElementCount(); i++) {
                fillSpecs(elem.getElement(i), specs, true);
            }

            if (includeRoot) {
                spec = new DefaultStyledDocument.ElementSpec(elem
                        .getAttributes(),
                        DefaultStyledDocument.ElementSpec.EndTagType);
                specs.add(spec);
            }
        }
    }