java压缩到二进制格式，然后解压缩

我有一个任务

将zip文件从本地读入二进制消息

以字符串形式通过EMS传输二进制消息（由java API完成）

以字符串形式接收传输的二进制消息（由java API完成）

解压缩二进制消息，然后将其打印出来

我面临的问题是解压缩消息时出现DataFormatException

我不知道哪一部分出了问题

我使用此命令将文件读入二进制消息：

static String readFile_Stream(String fileName) throws IOException {
    File file = new File(fileName);
    byte[] fileData = new byte[(int) file.length()];
    FileInputStream in = new FileInputStream(file);
    in.read(fileData);
    String content = "";
    System.out.print("Sent message: ");
    for(byte b : fileData)
    {
        System.out.print(getBits(b));
        content += getBits(b);
    }
    in.close();
    return content;
}

static String getBits(byte b)
{
    String result = "";
    for(int i = 0; i < 8; i++)
        result = ((b & (1 << i)) == 0 ? "0" : "1") + result;
    return result;
}

检查后，二进制消息在传输后不会损坏。

---

请帮助解决问题。

您是否尝试过使用InflaterInputStream？根据我的经验，直接使用充气机是相当棘手的。您可以使用此选项开始：

public static byte[] unzipByteArray(byte[] file) throws IOException {
  InflaterInputStream iis = new InflaterInputStream(new ByteArrayInputStream(file));
  ByteArrayOutputStream baos = new ByteArrayOutputStream();

  byte[] buffer = new byte[512];
  int length = 0;
  while ((length = iis.read(buffer, 0, buffer.length) != 0) {
    baos.write(buffer, 0, length);
  }

  iis.close();
  baos.close();

  return baos.toByteArray();
}

---

我终于解决了这个问题

问题是原始文件是一个.zip文件，所以在进一步处理之前，我应该使用zipInputStream解压该文件

public static byte[] unzipByteArray(byte[] file) throws IOException {

    // create a buffer to improve copy performance later.
    byte[] buffer = new byte[2048];
    byte[] content ;

    // open the zip file stream
    InputStream theFile = new ByteArrayInputStream(file);
    ZipInputStream stream = new ZipInputStream(theFile);
    ByteArrayOutputStream output = new ByteArrayOutputStream();

    try
    {

        ZipEntry entry;
        while((entry = stream.getNextEntry())!=null)
        {
            //String s = String.format("Entry: %s len %d added %TD", entry.getName(), entry.getSize(), new Date(entry.getTime()));
            //System.out.println(s);

            // Once we get the entry from the stream, the stream is
            // positioned read to read the raw data, and we keep
            // reading until read returns 0 or less.
            //String outpath = outdir + "/" + entry.getName();

            try
            {
                //output = new FileOutputStream(outpath);

                int len = 0;
                while ((len = stream.read(buffer)) > 0)
                {
                    output.write(buffer, 0, len);
                }
            }
            finally
            {
                // we must always close the output file
                if(output!=null) output.close();                                            
            }
        }            
    }
    finally
    {
        // we must always close the zip file.
        stream.close();            
    }
    content = output.toByteArray();

    return content;     

}

---

此代码适用于内部包含单个文件的zip文件。

尝试过。但是问题变成了java.util.zip.ZipException：未知的压缩方法

public static byte[] unzipByteArray(byte[] file) throws IOException {
  InflaterInputStream iis = new InflaterInputStream(new ByteArrayInputStream(file));
  ByteArrayOutputStream baos = new ByteArrayOutputStream();

  byte[] buffer = new byte[512];
  int length = 0;
  while ((length = iis.read(buffer, 0, buffer.length) != 0) {
    baos.write(buffer, 0, length);
  }

  iis.close();
  baos.close();

  return baos.toByteArray();
}

public static byte[] unzipByteArray(byte[] file) throws IOException {

    // create a buffer to improve copy performance later.
    byte[] buffer = new byte[2048];
    byte[] content ;

    // open the zip file stream
    InputStream theFile = new ByteArrayInputStream(file);
    ZipInputStream stream = new ZipInputStream(theFile);
    ByteArrayOutputStream output = new ByteArrayOutputStream();

    try
    {

        ZipEntry entry;
        while((entry = stream.getNextEntry())!=null)
        {
            //String s = String.format("Entry: %s len %d added %TD", entry.getName(), entry.getSize(), new Date(entry.getTime()));
            //System.out.println(s);

            // Once we get the entry from the stream, the stream is
            // positioned read to read the raw data, and we keep
            // reading until read returns 0 or less.
            //String outpath = outdir + "/" + entry.getName();

            try
            {
                //output = new FileOutputStream(outpath);

                int len = 0;
                while ((len = stream.read(buffer)) > 0)
                {
                    output.write(buffer, 0, len);
                }
            }
            finally
            {
                // we must always close the output file
                if(output!=null) output.close();                                            
            }
        }            
    }
    finally
    {
        // we must always close the zip file.
        stream.close();            
    }
    content = output.toByteArray();

    return content;     

}