如何从ZipInputStream获取每个ZipFile条目的字节/内容而不写入outputstream？ [英] How to get bytes/contents of each ZipFile entry from ZipInputStream without writing to outputstream?

问题描述

我试图从压缩文件输入流中获取特定文件的字节。我有压缩文件的输入流数据。从这我得到ZipEntry和写入每个ZipEntry的内容到输出流并返回字节缓冲区。这将返回缓冲区大小输出流，但不是每个特定文件的内容。有没有办法可以将FileOutputStream转换为字节或直接读取每个ZipEntry的字节？

我需要返回ZipEntry内容作为输出。

感谢您的帮助。

$ b $我不想写一个文件，只是得到每个zip条目的内容。 b

  public final class ArchiveUtils {
 
 private static String TEMP_DIR =/ tmp / unzip /; 
 
 public static byte [] unZipFromByteStream（byte [] data，String fileName）{
 
 ZipEntry entry = null; 
 ZipInputStream zis = new ZipInputStream（new ByteArrayInputStream（data））; 
文件tempDirectory = ensureTempDirectoryExists（TEMP_DIR）; （（entry = zis.getNextEntry（））！= null）{
 
 if（！entry.isDirectory（））{
 System。
尝试{
。 out.println（ - + entry.getName（））; 
 
 File file = new File（tempDirectory +/+ entry.getName（））; 
 $ b $ if（！new File（file.getParent（））。exists（））
 new File（file.getParent（））。mkdirs（）; 
 OutputStream out = new FileOutputStream（entry.getName（））; 
 byte [] byteBuff = new byte [1024]; 
 int bytesRead = 0; （byteRead = zis.read（byteBuff））！= -1）
（
 out.write（byteBuff，0，bytesRead）; 
} 
 out.close（）; 
 if（entry.getName（）。equals（fileName））{
 return byteBuff; 
 
 
 $ b} catch（Exception ex）{
 ex.printStackTrace（）; 
} 
返回null; 
 
 
 private static File ensureTempDirectoryExists（String outputPath）{
 
 File outputDirectory = new File（outputPath）; 
 if（！outputDirectory.exists（））{
 outputDirectory.mkdir（）; 
} 
 return outputDirectory; 
 
 $ / code> 

}


解决方案

使用 java .io.ByteArrayOutputStream 像这样 -

  ByteArrayOutputStream out = null; //在你的循环之外（对于范围）。 
 
 //你有一个FileOutputStream。 
 out = new ByteArrayOutputStream（）; //不使用entry.getName（）。 
  

然后您可以



  return（out == null）？ null：out.toByteArray（）; 
  




I am trying to get the bytes of a particular file from the zipped file input stream. I have the input stream data of the Zipped file. From this I am getting the ZipEntry and writing the contents of each ZipEntry to a output stream and returning the byte buffer. This will return the buffer size output stream, but not the contents of each particular file. Is there a way I can convert the FileOutputStream to bytes or directly read the bytes of each ZipEntry?

I need to return the ZipEntry contents as output. I dont want to write to a file but just get the contents of each zip entry.

Thank you for your help.

public final class ArchiveUtils {

private static String TEMP_DIR = "/tmp/unzip/";

public static byte[] unZipFromByteStream(byte[] data, String fileName) {

    ZipEntry entry = null;
    ZipInputStream zis = new ZipInputStream(new ByteArrayInputStream(data));
    File tempDirectory = ensureTempDirectoryExists(TEMP_DIR);
    try {
        while ((entry = zis.getNextEntry()) != null) {

            if (!entry.isDirectory()) {
                System.out.println("-" + entry.getName());

                File file = new File(tempDirectory + "/"+ entry.getName());

                if (!new File(file.getParent()).exists())
                    new File(file.getParent()).mkdirs();
                OutputStream out = new FileOutputStream(entry.getName());
                byte[] byteBuff = new byte[1024];
                int bytesRead = 0;
                while ((bytesRead = zis.read(byteBuff)) != -1)
                {
                    out.write(byteBuff, 0, bytesRead);
                }
                out.close();
                if(entry.getName().equals(fileName)){
                return byteBuff;
                }
            }
        }
    } catch (Exception ex) {
        ex.printStackTrace();
    }
    return null;
}

private static File ensureTempDirectoryExists(String outputPath) {

    File outputDirectory = new File(outputPath);
    if (!outputDirectory.exists()) {
        outputDirectory.mkdir();
    }
    return outputDirectory;
}

}

解决方案

Use a java.io.ByteArrayOutputStream like so -

ByteArrayOutputStream out = null; // outside of your loop (for scope).

// where you have a FileOutputStream.
out = new ByteArrayOutputStream(); // doesn't use entry.getName(). 

and then you can

return (out == null) ? null : out.toByteArray();

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