package com.wy.data.emaildata.util;

import org.apache.commons.io.FileUtils;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.File;

import java.io.IOException;

import java.util.zip.GZIPInputStream;

import java.util.zip.GZIPOutputStream;

import java.util.zip.ZipEntry;

import java.util.zip.ZipInputStream;

import java.util.zip.ZipOutputStream;

public class ZipUtils {

    /**

     * 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());

    }

    /**

     * <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;

    }

    /**

     * 使用zip进行压缩

     *

     * @param str 压缩前的文本

     * @return 返回压缩后的文本

     */

    public static final String zip(String str) {

        if (str == null)

            return null;

        byte[] compressed;

        ByteArrayOutputStream out = null;

        ZipOutputStream zout = null;

        String compressedStr = null;

        try {

            out = new ByteArrayOutputStream();

            zout = new ZipOutputStream(out);

            zout.putNextEntry(new ZipEntry("0"));

            zout.write(str.getBytes());

            zout.closeEntry();

            compressed = out.toByteArray();

            compressedStr = new sun.misc.BASE64Encoder().encodeBuffer(compressed);

        } catch (IOException e) {

            compressed = null;

        } finally {

            if (zout != null) {

                try {

                    zout.close();

                } catch (IOException e) {

                }

            }

            if (out != null) {

                try {

                    out.close();

                } catch (IOException e) {

                }

            }

        }

        return compressedStr;

    }

    /**

     * 使用zip进行解压缩

     *

     * @param compressedStr 压缩后的文本

     * @return 解压后的字符串

     */

    public static final String unzip(String compressedStr) {

        if (compressedStr == null) {

            return null;

        }

        ByteArrayOutputStream out = null;

        ByteArrayInputStream in = null;

        ZipInputStream zin = null;

        String decompressed = null;

        try {

            byte[] compressed = new sun.misc.BASE64Decoder().decodeBuffer(compressedStr);

            out = new ByteArrayOutputStream();

            in = new ByteArrayInputStream(compressed);

            zin = new ZipInputStream(in);

            zin.getNextEntry();

            byte[] buffer = new byte[1024];

            int offset = -1;

            while ((offset = zin.read(buffer)) != -1) {

                out.write(buffer, 0, offset);

            }

            decompressed = out.toString();

        } catch (IOException e) {

            decompressed = null;

        } finally {

            if (zin != null) {

                try {

                    zin.close();

                } catch (IOException e) {

                }

            }

            if (in != null) {

                try {

                    in.close();

                } catch (IOException e) {

                }

            }

            if (out != null) {

                try {

                    out.close();

                } catch (IOException e) {

                }

            }

        }

        return decompressed;

    }

    public static void main(String[] args) throws IOException {

       String strOld=FileUtils.readFileToString(new File("D:/test.txt"),"utf-8");

        System.out.println(strOld.length());

        String gzip = zip(strOld);

        System.out.println(gzip.length());

    }

}