GZIP压缩解压Java类

       当我们客户端与服务端进行数据传输时需要走流量，为了节省流量我们常常需要写一个压缩类对数据进行压缩。

import java.io.ByteArrayInputStream;        import java.io.ByteArrayOutputStream;        import java.io.IOException;        import java.util.zip.GZIPInputStream;        import java.util.zip.GZIPOutputStream;                /**        * GZIP压缩解压类        */        public class MessageGZIP {                        private static String encode = "utf-8";//"ISO-8859-1"                        public String getEncode() {                return encode;            }                    /*            * 设置 编码，默认编码：UTF-8            */            public void setEncode(String encode) {                MessageGZIP.encode = encode;            }                    /*            * 字符串压缩为字节数组            */            public static byte[] compressToByte(String str){                if (str == null || str.length() == 0) {                    return null;                }                ByteArrayOutputStream out = new ByteArrayOutputStream();                GZIPOutputStream gzip;                try {                    gzip = new GZIPOutputStream(out);                    gzip.write(str.getBytes(encode));                    gzip.close();                } catch (IOException e) {                    e.printStackTrace();                }                return out.toByteArray();            }                    /*            * 字符串压缩为字节数组            */            public static byte[] compressToByte(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) {                    e.printStackTrace();                }                return out.toByteArray();            }                    /*            * 字节数组解压缩后返回字符串            */            public static String uncompressToString(byte[] b) {                if (b == null || b.length == 0) {                    return null;                }                ByteArrayOutputStream out = new ByteArrayOutputStream();                ByteArrayInputStream in = new ByteArrayInputStream(b);                        try {                    GZIPInputStream gunzip = new GZIPInputStream(in);                    byte[] buffer = new byte[256];                    int n;                    while ((n = gunzip.read(buffer)) >= 0) {                        out.write(buffer, 0, n);                    }                } catch (IOException e) {                    e.printStackTrace();                }                return out.toString();            }                    /*            * 字节数组解压缩后返回字符串            */            public static String uncompressToString(byte[] b, String encoding) {                if (b == null || b.length == 0) {                    return null;                }                ByteArrayOutputStream out = new ByteArrayOutputStream();                ByteArrayInputStream in = new ByteArrayInputStream(b);                        try {                    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.toString(encoding);                } catch (IOException e) {                    e.printStackTrace();                }                return null;            }        }