java 将输出流转换为文件
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/17487709/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Convert Outputstream to file
提问by gmlyranetwork
Well i'm stucked with a problem,
好吧，我遇到了一个问题，
I need to create a PDF with a html source and i did this way:
我需要使用 html 源创建一个 PDF，我是这样做的：
File pdf = new File("/home/wrk/relatorio.pdf");
OutputStream out = new FileOutputStream(pdf);
InputStream input = new ByteArrayInputStream(build.toString().getBytes());//Build is a StringBuilder obj
Tidy tidy = new Tidy();
Document doc = tidy.parseDOM(input, null);
ITextRenderer renderer = new ITextRenderer();
renderer.setDocument(doc, null);
renderer.layout();
renderer.createPDF(out);
out.flush();
out.close();
well i'm using JSP so i need to download this file to the user not write in the server...
好吧，我正在使用 JSP，所以我需要将此文件下载给用户，而不是写入服务器...
How do I transform this Outputstream output to a file in the java without write this file in hard drive ?
如何将此 Outputstream 输出转换为 java 中的文件而不将此文件写入硬盘驱动器？
采纳答案by g0dkar
If you're using VRaptor 3.3.0+ you can use the ByteArrayDownloadclass. Starting with your code, you can use this:
如果您使用的是 VRaptor 3.3.0+，则可以使用ByteArrayDownload该类。从你的代码开始，你可以使用这个：
@Path("/download-relatorio")
public Download download() {
// Everything will be stored into this OutputStream
ByteArrayOutputStream out = new ByteArrayOutputStream();
InputStream input = new ByteArrayInputStream(build.toString().getBytes());
Tidy tidy = new Tidy();
Document doc = tidy.parseDOM(input, null);
ITextRenderer renderer = new ITextRenderer();
renderer.setDocument(doc, null);
renderer.layout();
renderer.createPDF(out);
out.flush();
out.close();
// Now that you have finished, return a new ByteArrayDownload()
// The 2nd and 3rd parameters are the Content-Type and File Name
// (which will be shown to the end-user)
return new ByteArrayDownload(out.toByteArray(), "application/pdf", "Relatorio.pdf");
}
回答by Michael Lang
A Fileobject does not actually hold the data but delegates all operations to the file system (see this discussion).
You could, however, create a temporary file using File.createTempFile. Also look herefor a possible alternative without using a Fileobject.
一个File对象不实际保存数据，但代表所有操作的文件系统（见讨论）。但是，您可以使用File.createTempFile. 还可以在此处查找不使用File对象的可能替代方案。
回答by Rotom92
use temporary files.
使用临时文件。
File temp = File.createTempFile(prefix ,suffix);
prefix -- The prefix string defines the files name; must be at least three characters long.
prefix -- 前缀字符串定义文件名；长度必须至少为三个字符。
suffix -- The suffix string defines the file's extension; if null the suffix ".tmp" will be used.
suffix -- 后缀字符串定义文件的扩展名；如果为空，将使用后缀“.tmp”。
