k8king
10/17/2019 - 2:37 AM

java压缩与解压

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

/**
 * 对字符串进行压缩及解压 
 */
public class ZipUtil {
    /**
     *
     * 使用gzip进行压缩
     */
    public static String gzip(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) {
            e.printStackTrace();
        } finally {
            if (gzip != null) {
                try {
                    gzip.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return new sun.misc.BASE64Encoder().encode(out.toByteArray()).replaceAll("[\\s*\t\n\r]", "");
    }


    /**
     *
     * <p>
     * Description:使用gzip进行解压缩
     * </p>
     *
     * @param compressedStr
     * @return
     */
    public static String gunzip(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) {
                }
            }
            if (out != null) {
                try {
                    out.close();
                } catch (IOException e) {
                }
            }
        }
        return decompressed;
    }

    /**
     * 字符串压缩解压测试
     * @param args
     */
    public static void main(String[] args) {
        String s = "人闲桂花落,夜静春山空。月出惊山鸟,时鸣春涧中。";
        String zippedStr = gzip(s);
        System.out.println("zippedStr = "+zippedStr);
        String ss = gunzip(zippedStr);
        System.out.println("ss = "+ss);
    }
}