API练习 待扩充..

JAVA是很强大的，而这种强大很大程度上得益于JAVA强大的类库。API调用不可耻！可耻的是调用API都不会！

package com.gzip.demo;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

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

/**
* gzip压缩与解压缩，同时结合BASE64输出加密密文
* 
*/
public class TestGzip {
    /**
    * gzip压缩
    */
    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 ( Exception e) {
            e.printStackTrace();
        }
        return out.toByteArray();
    }
    /**
    * gzip解压缩  
    * TODO  read的字节数可能大于字节数组的大小，待完善
    */
    public static byte[] uncompress(byte[] bytes) {
        if (bytes == null || bytes.length == 0) {
            return null;
        }
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        ByteArrayInputStream in = new ByteArrayInputStream(bytes);
        try {
            GZIPInputStream ungzip = new GZIPInputStream(in);
            byte[] buffer = new byte[256];
            int n;
            while ((n = ungzip.read(buffer)) >= 0) {
                out.write(buffer, 0, n);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return out.toByteArray();
    }

    /**
     * gzip+base64 返回舒服的英文加密串
     * 
     */
    public static String compressToString(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 ( Exception e) {
            e.printStackTrace();
        }
        return new BASE64Encoder().encode(out.toByteArray());
    }
     /**
     * 解密并解压缩加密后的压缩数据
     *
     */
     public static byte[] uncompressEncodedeString(String str) {
        byte[] bytes= new BASE64Decoder().decodeBuffer(str);
        if (bytes == null || bytes.length == 0) {
            return null;
        }
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        ByteArrayInputStream in = new ByteArrayInputStream(bytes);
        try {
            GZIPInputStream ungzip = new GZIPInputStream(in);
            byte[] buffer = new byte[256];
            int n;
            while ((n = ungzip.read(buffer)) >= 0) {
                out.write(buffer, 0, n);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return out.toByteArray();
    }
}