ZipOutputStream离开大小=-1

Question

我正在用ZipOutputStream用非常标准的代码创建一个压缩文件。出于某种原因，当我将它作为ZipInputStream读回来时，ZipEntry有size=-1。文件名已正确存储在ZipEntry中。

(当我使用操作系统工具创建一个压缩文件，然后读回它时，大小是正确的，所以我认为问题出在ZipOutputStream，而不是ZipInputStream)。

上下文是一个Spring MVC控制器。

我做错了什么？谢谢。

代码如下：

// export zip file
String file = "/Users/me/Desktop/test.jpg";
FileInputStream fis = new FileInputStream(file);
FileOutputStream fos = new FileOutputStream(file+".zip");
ZipOutputStream zos = new ZipOutputStream(fos);
zos.putNextEntry(new ZipEntry("test.jpg"));
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = fis.read(buffer)) > 0) {
    zos.write(buffer, 0, bytesRead);
}
zos.closeEntry();
zos.close();
fis.close();

// import same file
String file2 = "/Users/me/Desktop/test.jpg.zip";
FileInputStream fis2 = new FileInputStream(file2);
ZipInputStream zis = new ZipInputStream(fis2);
ZipEntry entry = zis.getNextEntry();
// here: entry.getSize() = -1, zip.buf is an array of zeros... 
// but if I unzip the file on my OS I see that the original file has been zipped...

Answer 1

看起来entry.getSize()根本就不可靠：Why ZipInputStream can't read the output of ZipOutputStream?

上面的帖子提供了一个合适的解决方法。

Answer 2

您必须从流中获取下一个条目，如下例所示：

http://www.roseindia.net/tutorial/java/corejava/zip/zipentry.html

当你手动设置大小时，它肯定会给你一个结果，就像你已经显示的"64527“一样。您最好看一下zip示例。他们会给你一个清晰的图像。还有：Create Java-Zip-Archive from existing OutputStream

尝试一下，就像这样：

        String inputFileName = "test.txt";
        String zipFileName = "compressed.zip";

        //Create input and output streams
        FileInputStream inStream = new FileInputStream(inputFileName);
        ZipOutputStream outStream = new ZipOutputStream(new FileOutputStream(zipFileName));

        // Add a zip entry to the output stream
        outStream.putNextEntry(new ZipEntry(inputFileName));

        byte[] buffer = new byte[1024];
        int bytesRead;

        //Each chunk of data read from the input stream 
        //is written to the output stream
        while ((bytesRead = inStream.read(buffer)) > 0) {
            outStream.write(buffer, 0, bytesRead);
        }

        //Close zip entry and file streams
        outStream.closeEntry();

        outStream.close();
        inStream.close();