MessageFormat格式化数字问题

Question

MessageFormat mf = new MessageFormat("数字{0}");
System.out.println(mf.format(new Object[] { 12345 }));// 输出结果为:数字12,345
怎么去的结果里面的,啊不要说用String的replace啊....

Answer 1

System.out.println(mf.format(new Object[] { 12345+"" }));

Answer 2

你这个完全当字符串处理了,浪费MessageFormat的能力!假如我是小数的话,怎么格式化他的小数位??
谁来回答下啊

Answer 3

MessageFormat mf = new MessageFormat("数字{0,number,#.##}");
System.out.println(mf.format(new Object[] { 12345.222 }));//去掉逗号,保留两位小数

Answer 4

NumberFormat nf = NumberFormat.getInstance();
float dblNum = 10f;
nf.setMaximumFractionDigits(2);

Answer 5

用stringBuffer进行组装的，
先找出每个参数的位置，一直参数的个数
逐一对结果按位置进行组装代码如下：private StringBuffer subformat(Object[] arguments, StringBuffer result,
                                   FieldPosition fp, List characterIterators) {
        // note: this implementation assumes a fast substring & index.
        // if this is not true, would be better to append chars one by one.
        int lastOffset = 0;
        int last = result.length();
        for (int i = 0; i <= maxOffset; ++i) {
            result.append(pattern.substring(lastOffset, offsets[i]));
            lastOffset = offsets[i];
            int argumentNumber = argumentNumbers[i];
            if (arguments == null || argumentNumber >= arguments.length) {
                result.append("{" + argumentNumber + "}");
                continue;
            }
            // int argRecursion = ((recursionProtection >> (argumentNumber*2)) & 0x3);
            if (false) { // if (argRecursion == 3){
                // prevent loop!!!
                result.append('\uFFFD');
            } else {
                Object obj = arguments[argumentNumber];
                String arg = null;
                Format subFormatter = null;
                if (obj == null) {
                    arg = "null";
                } else if (formats[i] != null) {
                    subFormatter = formats[i];
                    if (subFormatter instanceof ChoiceFormat) {
                        arg = formats[i].format(obj);
                        if (arg.indexOf('{') >= 0) {
                            subFormatter = new MessageFormat(arg, locale);
                            obj = arguments;
                            arg = null;
                        }
                    }
                } else if (obj instanceof Number) {
                    // format number if can
                    subFormatter = NumberFormat.getInstance(locale);
                } else if (obj instanceof Date) {
                    // format a Date if can
                    subFormatter = DateFormat.getDateTimeInstance(
                             DateFormat.SHORT, DateFormat.SHORT, locale);//fix
                } else if (obj instanceof String) {
                    arg = (String) obj;                } else {
                    arg = obj.toString();
                    if (arg == null) arg = "null";
                }                // At this point we are in two states, either subFormatter
                // is non-null indicating we should format obj using it,
                // or arg is non-null and we should use it as the value.                if (characterIterators != null) {
                    // If characterIterators is non-null, it indicates we need
                    // to get the CharacterIterator from the child formatter.
                    if (last != result.length()) {
                        characterIterators.add(
                            createAttributedCharacterIterator(result.substring
                                                              (last)));
                        last = result.length();
                    }
                    if (subFormatter != null) {
                        AttributedCharacterIterator subIterator =
                                   subFormatter.formatToCharacterIterator(obj);                        append(result, subIterator);
                        if (last != result.length()) {
                            characterIterators.add(
                                         createAttributedCharacterIterator(
                                         subIterator, Field.ARGUMENT,
                                         new Integer(argumentNumber)));
                            last = result.length();
                        }
                        arg = null;
                    }
                    if (arg != null && arg.length() > 0) {
                        result.append(arg);
                        characterIterators.add(
                                 createAttributedCharacterIterator(
                                 arg, Field.ARGUMENT,
                                 new Integer(argumentNumber)));
                        last = result.length();
                    }
                }
                else {
                    if (subFormatter != null) {
                        arg = subFormatter.format(obj);
                    }
                    last = result.length();
                    result.append(arg);
                    if (i == 0 && fp != null && Field.ARGUMENT.equals(
                                  fp.getFieldAttribute())) {
                        fp.setBeginIndex(last);
                        fp.setEndIndex(result.length());
                    }
                    last = result.length();
                }
            }
        }
        result.append(pattern.substring(lastOffset, pattern.length()));
        if (characterIterators != null && last != result.length()) {
            characterIterators.add(createAttributedCharacterIterator(
                                   result.substring(last)));
        }
        return result;
    }