Java 通过 StringBuilder 输出流

Output stream over a StringBuilder

提问by rocketboy

I think this has been answered but I can't seem to find it.

我认为这已经得到了回答，但我似乎无法找到它。

I have an instance method which writes some contents to an output stream

我有一个实例方法将一些内容写入输出流

writeTo(OutputStream){
     //class specific logic
}

I want it to get these contents into a StringBuilder. I can do this via a temporary file but that does not seem right. I want to do something like:

我希望它将这些内容放入 StringBuilder。我可以通过一个临时文件来做到这一点，但这似乎不对。我想做类似的事情：

Stringbuilder sb = /* */;
OutputStream os = outForStringBuilder(sb);//not sure how to do this
instance.writeTo(os); //This should write the contents to Stringbuilder

采纳答案by Centijo

So you are wanting output written to the stream to go to a StringBuffer instead. I am assuming you are doing this because an OutputStream is required somewhere else. You could use ByteArrayOutputStream, but if you want to preserve the StringBuffer behavior, you might simply wrap a StringBuffer in a subclass of OutputStream like the code here:

因此，您希望写入流的输出改为转到 StringBuffer。我假设您这样做是因为其他地方需要一个 OutputStream。您可以使用 ByteArrayOutputStream，但如果您想保留 StringBuffer 行为，您可以简单地将 StringBuffer 包装在 OutputStream 的子类中，如以下代码：

http://geronimo.apache.org/maven/specs/geronimo-javamail_1.4_spec/1.6/apidocs/src-html/org/apache/geronimo/mail/util/StringBufferOutputStream.html#line.31

http://geronimo.apache.org/maven/specs/geronimo-javamail_1.4_spec/1.6/apidocs/src-html/org/apache/geronimo/mail/util/StringBufferOutputStream.html#line.31

回答by Tom

Use a ByteArrayOutputStreamand then call toString(charSet) - no need for a StringBuilder.

使用ByteArrayOutputStream然后调用 toString(charSet) - 不需要 StringBuilder。