java 读取文件 获取byte[]字节 并执行Gzip的压缩和解压

import java.io.*;
import java.lang.reflect.Method;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
import org.apache.commons.lang3.ArrayUtils;
public class fileTest {
    public static final String GZIP_ENCODE_UTF_8 = "UTF-8";
    public static byte[] compress(String str) {
        return compress(str, GZIP_ENCODE_UTF_8);
    }
    public static byte[] compress(String str, String encoding) {
        if (str == null || str.length() == 0) {
            return null;
        }
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        GZIPOutputStream gzip;
        try {
            gzip = new GZIPOutputStream(out);
            gzip.write(str.getBytes(encoding));
            gzip.close();
        } catch (IOException e) {
            System.out.println("gzip uncompress error."+e);
        }
        return out.toByteArray();
    }
    public static byte[] getGzipBytesByFile(String pathStr) {
        File file = new File(pathStr);
        try {
            FileInputStream fis = new FileInputStream(file);
            ByteArrayOutputStream bos = new ByteArrayOutputStream(1000);
            byte[] b = new byte[1000];
            int n;
            while ((n = fis.read(b)) != -1) {
                bos.write(b, 0, n);
            }
            fis.close();
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            GZIPOutputStream gzip = new GZIPOutputStream(out);
            gzip.write(bos.toByteArray());
            gzip.close();
            return out.toByteArray();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
    public static byte[] unGzip(byte[] bytes) throws Exception{
        java.io.ByteArrayOutputStream out = new java.io.ByteArrayOutputStream();
        java.io.ByteArrayInputStream in = new java.io.ByteArrayInputStream(bytes);
        java.util.zip.GZIPInputStream ungzip = new java.util.zip.GZIPInputStream(in);
        byte[] buffer = new byte[256];
        int n;
        while ((n = ungzip.read(buffer)) >= 0)
            out.write(buffer, 0, n);
        return out.toByteArray();
    }
    public static void main(String args[]) throws Exception {
        byte[] fileBytes = getGzipBytesByFile("F:\\test.class");
        String GzipBytes = ArrayUtils.toString(fileBytes);
        System.out.println(GzipBytes);
        System.out.println(unGzip(fileBytes));
    }
}