java GZIP压缩和解压

最近碰到了一个按GZIP解压指定的输入流数据，备份下

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

/**
 * 压缩，解压类
 */
public class ZipUtils {

    /**
     * 压缩指定的字符串
     *
     * @param str
     * @return
     * @throws IOException
     */
    public static byte[] compress(String str) throws IOException {

        ByteArrayOutputStream out = new ByteArrayOutputStream();
        GZIPOutputStream gzip = new GZIPOutputStream(out);
        gzip.write(str.getBytes());
        gzip.close();
        return out.toByteArray();
    }

    /**
     * 解压缩字节数组
     *
     * @param b
     * @return
     * @throws IOException
     */
    public static byte[] uncompress(byte[] b) throws IOException {

        ByteArrayOutputStream out = new ByteArrayOutputStream();
        ByteArrayInputStream in = new ByteArrayInputStream(b);
        GZIPInputStream gunzip = new GZIPInputStream(in);
        byte[] buffer = new byte[256];
        int n;
        while ((n = gunzip.read(buffer)) >= 0) {
            out.write(buffer, 0, n);
        }
        return out.toByteArray();
    }

    // 测试方法
    public static void main(String[] args) throws IOException {

    }

}  

注意事项

      解压方法最后不要转成字符串  out.toString(); 否则解压的时候会出现  Not in GZIP format 错误