文件压缩 ZipOutputStream

   用ZipOutputStream来压缩一个文件夹时，要搭配ZipEntry来使用。ZipEntry是用来创建压缩文件的。

  举个例子，向压缩文件中添加一个文件的代码：

//zipOut：压缩文件的路径ZipOutputStream zipOutputStream = new ZipOutputStream(new FileOutputStream(zipOut));//zipOutputStream.putNextEntry()  ====> 向压缩包中添加一个文件//new ZipEntry("text1.txt") ======⇒ zip压缩包中文件都是用ZipEntry对象，//"text1.txt"===》是文件在压缩文件的路径，text1.txt表示在压缩文件的根路径zipOutputStream.putNextEntry(new ZipEntry("text1.txt"));

如下图：



  在创建ZipEntry对象时可以指定文件在压缩包的位置：new ZipEntry(“second-dir\second-01.txt”)

  在使用ZipOutputStream压缩文件时要注意的地方就是这些，下面给一个压缩文件的代码：

    static final int  BUFFER_SIZE = 4 << 10;        public void zip(String dir,String zipPath,String destZipName) throws ioException {        File file = new File(dir);                String path = file.getParentFile().getAbsolutePath();        if(isNull(destZipName))destZipName = file.getName()+".zip";        if(isNull(zipPath)) zipPath = path;        String zipOut = zipPath + File.separator + destZipName;        File zipOutFile = new File(zipOut);        if(!zipOutFile.getParentFile().exists()){            zipOutFile.getParentFile().mkdirs();        }                       ZipOutputStream zipOutputStream = new ZipOutputStream(new FileOutputStream(zipOut));        if(!file.isDirectory())zipOutputStream.close();        File[] subFiles = file.listFiles();        for (File subFile : subFiles) {            buildZipDir(zipOutputStream,subFile,null);        }        zipOutputStream.close();    }    void buildZipDir(ZipOutputStream zipOut,File file,String baseDir) throws IOException {        if(file.isFile()){            String zipEntryName = baseDir == null ? file.getName() : baseDir+File.separator+file.getName();            zipOut.putNextEntry(new ZipEntry(zipEntryName));            byte[] buffer = new byte[BUFFER_SIZE];            try(InputStream inputStream = new FileInputStream(file)){                int len = -1;                while((len = inputStream.read(buffer)) != -1){                    zipOut.write(buffer,0,len);                }                zipOut.flush();                zipOut.closeEntry();            }        }        else{//文件是dir，继续递归找文件            File[] subFiles = file.listFiles();            if(subFiles.length ==0){//处理空文件夹                String zipName = baseDir == null ? file.getName() :baseDir + File.separator+ file.getName() ;                zipOut.putNextEntry(new ZipEntry(zipName));                zipOut.closeEntry();            }else{                for (File subFile : subFiles) {                    String subBaseDir =baseDir == null ? file.getName() :baseDir + File.separator+ file.getName() ;                    buildZipDir(zipOut,subFile,subBaseDir);                }            }        }    }    public boolean isNull(String str){        return str == null || str.equals("");    }

测试：

    @Test    public void testZip() throws IOException {     String dir = "D:\\test-zip";     //dir : 要压缩的目录     //D:\\yy\\    指定压缩文件的位置     //path-test.zip 指定压缩文件的名字     zip(dir,"D:\\yy\\","path-test.zip");    }

文件解压：ZipInputStream

  ZipInputStream读取压缩文件，配合ZipFile使用；通过上面的例子，我们知道压缩包里的是一个个ZipEntry对象，在解压时，可以遍历压缩包获取到ZipEntry对象。每一个ZipEntry对象都是一个文件，使用ZipFile可以获取到每一个ZipEntry对象的文件流；获取到文件流就可以将压缩包的文件读出来了。

    public void unZip(String zipPath,String unzipPath) throws IOException {        File file = new File(zipPath);        ZipFile zipFile = new ZipFile(file);//zip文件        ZipInputStream zipInputStream = new ZipInputStream(new FileInputStream(file));        if(isNull(unzipPath))unzipPath = zipPath.replace(".zip","");        ZipEntry nextEntry = null;        while( (nextEntry = zipInputStream.getNextEntry()) != null){            String name = nextEntry.getName();            String fileOutPath = unzipPath + File.separator + name;            File fileOut = new File(fileOutPath);            if(!fileOut.getParentFile().exists()){                fileOut.getParentFile().mkdirs();            }            if(!fileOut.exists()){                fileOut.createNewFile();            }            OutputStream  output = new FileOutputStream(fileOutPath);            InputStream inputStream = zipFile.getInputStream(nextEntry);//通过ZipFile获取到ZipEntry的文件流            int read = -1;            byte[] buffer = new byte[BUFFER_SIZE];            while((read = inputStream.read(buffer) ) != -1){                output.write(buffer,0, read);            }            output.flush();            output.close();            inputStream.close();        }        zipInputStream.close();        zipFile.close();    }

测试：

   public void testUnzip() throws IOException {        String zip = "D:\\yy\\path-test.zip";        unZip(zip,null);    }

来源地址：https://blog.csdn.net/m0_37550986/article/details/131198351