没有任何编码的Gzip压缩和解压缩

Question

我想在java中解压缩一个字符串，它在Python中被gzip压缩。

java.io.IOException: Not in GZIP format at 
java.util.zip.GZIPInputStream.readHeader(GZIPInputStream.java:154)
    at java.util.zip.GZIPInputStream.<init>(GZIPInputStream.java:75)
    at java.util.zip.GZIPInputStream.<init>(GZIPInputStream.java:85)
    at GZipFile.gunzipIt(GZipFile.java:58)
    at GZipFile.main(GZipFile.java:42)

import StringIO  
import gzip  
import base64  
import os  


m='hello'+'\r\n'+'world'  

out = StringIO.StringIO()  
with gzip.GzipFile(fileobj=out, mode="wb") as f:  

    f.write(m)  
f=open('comp_dump','wb')  
f.write(base64.b64encode(out.getvalue()))  
f.close()  

这是Java中的解压缩代码：

//$Id$

import java.io.*;  
import java.io.FileInputStream;  
import java.io.FileOutputStream;  
import java.io.IOException;  
import java.util.zip.GZIPInputStream;  
import javax.xml.bind.DatatypeConverter;  
import java.util.Arrays;

public class GZipFile
{


    public static String readCompressedData()throws Exception
    {
            String compressedStr ="";
            String nextLine;
            BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream("comp_dump")));
            try
            {
                    while((nextLine=reader.readLine())!=null)
                    {
                            compressedStr += nextLine;
                    }
            }
            finally
            {
                    reader.close();
            }
            return compressedStr;
    }

    public static void main( String[] args ) throws Exception
    {
            GZipFile gZip = new GZipFile();
            byte[] contentInBytes = DatatypeConverter.parseBase64Binary(readCompressedData());

            String decomp = gZip.gunzipIt(contentInBytes);
            System.out.println(decomp);
    }

    /**
     * GunZip it
     */
    public static String gunzipIt(final byte[] compressed){

            byte[] buffer = new byte[1024];
            StringBuilder decomp = new StringBuilder() ;

            try{

                    GZIPInputStream gzis = new GZIPInputStream(new ByteArrayInputStream(compressed));

                    int len;
                    while ((len = gzis.read(buffer)) > 0) {

                            decomp.append(new String(buffer, 0, len));

                    }

                    gzis.close();

            }catch(IOException ex){
                    ex.printStackTrace();
            }
            return decomp.toString();
    }

}

Answer 1

不是每个byte[]都可以转换成字符串，转换回来可能会给出其他字节。

请在压缩时明确定义编码，在解压缩时也这样做。否则您的OS、JVM等...会为你做的。很可能会把事情搞砸。

例如：在我的Linux机器上：

import sys
print sys.getdefaultencoding()
>> ascii

爪哇

System.out.println(Charset.defaultCharset());
>> UTF-8

相关解答:https://stackoverflow.com/a/14467099/3014866