string.format / formatter中的错误？

Question

我试图创建一个非常大的字符串。事实证明， Formatter 类窒息宽度规格超过Integer.MAX_VALUE：

// Produces an empty string. (2147483648 = Integer.MAX_VALUE + 1)
String.format("%2147483648s", "");

. 所以我走了去验证它确实根据规格。但它所说的只是

如果格式说明符包含具有无效值的宽度或精度，或者不支持，则分别抛出IllegalFormatWidthException或IllegalFormatPrecisionException。

所以在我看来，正确的行为是抛出一个生成的。

是这个错误（？）记录在某个地方？ （如果没有，我会报告它。）

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也，应该注意的是，如果一个人在宽度前面放置一个IllegalFormatWidthException（以左对齐输出）：

String.format("%-2147483648s", "");

.

确实抛出了一个生成的（当我看到它时，似乎是正确的行为）。

（我正在使用OpenJDK 1.6.0_20。）

Answer 1

I think you're right and that it's a bug: it should throw IllegalFormatWidthException, if any existing exception.

The javadoc for that exception says "Unchecked exception thrown when the format width is a negative value other than -1 or is otherwise unsupported", which oddly doesn't specifically mention values that are too large. I think the "otherwise unsupported" clause makes this a reasonable exception to throw.

Answer 2

The format/formatter documentation should address this case, which is caused by trying to write a string to the format's appender that exceeds the maximum length of a string. If you actually needed to do this, you would have to use a stream.

See String's Maximum length in Java - calling length() method