格式化json字符串换行缩进工具类

格式化json字符串按照json格式显示：换行、缩进显示

public class JsonFormatter {
    public static String format(String jsonStr){
        if (StringUtils.isEmpty(jsonStr)) {
            return "";
        }
        try {
            ByteArrayInputStream in = new ByteArrayInputStream(jsonStr.getBytes());
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            char preCh = ' ';
            char ch;
            int read;
            int tb=0;
            while((read = in.read()) > 0){
                ch = (char)read;
                switch (ch){
                    case '{': {
                        tb = outputAndRightMove(tb, ch, out, preCh);
                        break;
                    }
                    case '[': {
                        out.write(ch);
                        tb += 1;
                        break;
                    }
                    case '}': {
                        tb = outputAndLeftMove(tb, ch, out);
                        break;
                    }
                    case ']': {
                        tb = outputAndLeftMove(tb, ch, out);
                        break;
                    }
                    case ',': {
                        out.write(ch);
                        outputNewline(out);
                        out.write(getBlankingStringBytes(tb));
                        break;
                    }
                    default: {
                        out.write(ch);
                        break;
                    }
                }
                preCh = ch;
            }
            return out.toString();
        } catch (IOException e){
            e.printStackTrace();
        }

        return null;
    }

    public static int outputAndRightMove(int tb, char ch, ByteArrayOutputStream out, char preCh) throws IOException {
        if (preCh != ':' && preCh != ',') {
            //换行
            outputNewline(out);
        }
        if ((preCh != ',' && ch != '{') || (preCh == '[' && ch == '{')) {
            //向右缩进
            out.write(getBlankingStringBytes(tb));
        }
        out.write(ch);
        outputNewline(out);
        tb += 1;
        //再向右缩进多四个字符
        out.write(getBlankingStringBytes(tb));
        return tb;
    }
    public static int outputAndLeftMove(int tb, char ch, ByteArrayOutputStream out) throws IOException{
        outputNewline(out);
        tb -= 1;
        out.write(getBlankingStringBytes(tb));
        out.write(ch);
        return tb;
    }
    public static byte[] getBlankingStringBytes(int tb){
        StringBuilder sb = new StringBuilder("");
        for (int i = 0; i < tb; i++) {
            sb.append("\t");
        }
        return sb.toString().getBytes();
    }

    public static void outputNewline(ByteArrayOutputStream out){
        out.write('\n');
    }
}