kq-value-added-project/kqapi/src/main/java/com/ningdatech/kqapi/common/util/GzipUtils.java

package com.ningdatech.kqapi.common.util;

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

/**
 * <p>
 * 压缩为Gzip
 * </p>
 *
 * @author WendyYang
 */
public class GzipUtils {
    /**
     * 使用gzip进行压缩
     */
    public static String compress(String primStr) {
        if (primStr == null || primStr.length() == 0) {
            return primStr;
        }
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        GZIPOutputStream gzip = null;
        try {
            gzip = new GZIPOutputStream(out);
            gzip.write(primStr.getBytes());
        } catch (IOException e) {
            throw new RuntimeException(e);
        } finally {
            if (gzip != null) {
                try {
                    gzip.close();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
        }
        return new sun.misc.BASE64Encoder().encode(out.toByteArray());
    }

    /**
     * 使用gzip进行解压缩
     */
    public static String uncompress(String compressedStr) {
        if (compressedStr == null) {
            return null;
        }
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        ByteArrayInputStream in = null;
        GZIPInputStream ginzip = null;
        byte[] compressed = null;
        String decompressed = null;
        try {
            compressed = new sun.misc.BASE64Decoder().decodeBuffer(compressedStr);
            in = new ByteArrayInputStream(compressed);
            ginzip = new GZIPInputStream(in);

            byte[] buffer = new byte[1024];
            int offset = -1;
            while ((offset = ginzip.read(buffer)) != -1) {
                out.write(buffer, 0, offset);
            }
            decompressed = out.toString();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (ginzip != null) {
                try {
                    ginzip.close();
                } catch (IOException e) {
                }
            }
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                }
            }
            try {
                out.close();
            } catch (IOException e) {
            }
        }
        return decompressed;
    }

}