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压缩算法 |

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ZipOutputStream

ZipInputStream

GZIPOutputStream

GZIPInputStream

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zip压缩与解压缩

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/**

* 解压文件

* @param file 压缩文件

* @param targetDir 解压文件输出的目录

* @throws IOException

*/

public static void unPacket(Path file, Path targetDir) throws IOException {

if (!Files.exists(targetDir)) {

Files.createDirectories(targetDir);

}

// 创建zip对象

ZipFile zipFile = new ZipFile(file.toFile());

try {

// 读取zip流

try(ZipInputStream zipInputStream = new ZipInputStream(Files.newInputStream(file))){

ZipEntry zipEntry = null;

// 遍历每一个zip项

while ((zipEntry = zipInputStream.getNextEntry()) != null) {

// 获取zip项目名称

String entryName = zipEntry.getName();

// 构建绝对路径

Path entryFile = targetDir.resolve(entryName);

if(zipEntry.isDirectory()) { // 文件夹

if (!Files.isDirectory(entryFile)) {

Files.createDirectories(entryFile);

}

} else { // 文件

// 读取zip项数据流

try(InputStream zipEntryInputStream = zipFile.getInputStream(zipEntry)){

try(OutputStream fileOutputStream = Files.newOutputStream(entryFile, StandardOpenOption.CREATE_NEW)){

byte[] buffer = new byte[4096];

int length = 0;

while ((length = zipEntryInputStream.read(buffer)) != -1) {

fileOutputStream.write(buffer, 0, length);

}

fileOutputStream.flush();

}

}

}

}

}

} finally {

zipFile.close();

}

}

/**

* 压缩指定的文件

* @param files 目标文件

* @param zipFile 生成的压缩文件

* @throws IOException

*/

public static void packet(Path[] files, Path zipFile) throws IOException {

OutputStream outputStream = Files.newOutputStream(zipFile, StandardOpenOption.CREATE_NEW);

ZipOutputStream zipOutputStream = new ZipOutputStream(outputStream);

try {

for (Path file : files) {

if (Files.isDirectory(file)) {

continue;

}

try (InputStream inputStream = Files.newInputStream(file)) {

// 创建一个压缩项，指定名称

ZipEntry zipEntry = new ZipEntry(file.getFileName().toString());

// 添加到压缩流

zipOutputStream.putNextEntry(zipEntry);

// 设置注释

zipOutputStream.setComment("我是注释");

// 写入数据

int len = 0;

byte[] buffer = new byte[1024 * 10];

while ((len = inputStream.read(buffer)) > 0) {

zipOutputStream.write(buffer, 0, len);

}

zipOutputStream.flush();

}

}

// 完成所有压缩项的添加

zipOutputStream.closeEntry();

} finally {

zipOutputStream.close();

outputStream.close();

}

}

/**

* 压缩指定的目录

* @param folder

* @param zipFile

* @throws IOException

*/

public static void packet(Path folder, Path zipFile) throws IOException {

if (!Files.isDirectory(folder)) {

throw new IllegalArgumentException(folder.toString() + " 不是合法的文件夹");

}

OutputStream outputStream = Files.newOutputStream(zipFile, StandardOpenOption.CREATE_NEW);

ZipOutputStream zipOutputStream = new ZipOutputStream(outputStream);

LinkedList<String> path = new LinkedList<>();

try {

Files.walkFileTree(folder, new FileVisitor<Path>() {

@Override

public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {

if (!dir.equals(folder)) {

// 开始遍历目录

String folder = dir.getFileName().toString();

path.addLast(folder);

// 写入目录

ZipEntry zipEntry = new ZipEntry(path.stream().collect(Collectors.joining("/", "", "/")));

try {

zipOutputStream.putNextEntry(zipEntry);

zipOutputStream.flush();

} catch (IOException e) {

throw new RuntimeException(e);

}

}

return FileVisitResult.CONTINUE;

}

@Override

public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {

// 开始遍历文件

try (InputStream inputStream = Files.newInputStream(file)) {

// 创建一个压缩项，指定名称

String fileName = path.size() > 0

? path.stream().collect(Collectors.joining("/", "", "")) + "/" + file.getFileName().toString()

: file.getFileName().toString();

ZipEntry zipEntry = new ZipEntry(fileName);

// 添加到压缩流

zipOutputStream.putNextEntry(zipEntry);

// 写入数据

int len = 0;

byte[] buffer = new byte[1024 * 10];

while ((len = inputStream.read(buffer)) > 0) {

zipOutputStream.write(buffer, 0, len);

}

zipOutputStream.flush();

} catch (IOException e) {

throw new RuntimeException(e);

}

return FileVisitResult.CONTINUE;

}

@Override

public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {

return FileVisitResult.CONTINUE;

}

@Override

public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {

// 结束遍历目录

if (!path.isEmpty()) {

path.removeLast();

}

return FileVisitResult.CONTINUE;

}

});

zipOutputStream.closeEntry();

} finally {

zipOutputStream.close();

outputStream.close();

}

}

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GIZ压缩/解压缩 |

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/**

* 压缩

* @param data

* @return

* @throws IOException

*/

public static byte[] gZip(byte[] data) throws IOException {

byte[] bytes = null;

ByteArrayOutputStream byteArrayOutputStream = null;

GZIPOutputStream gzipOutputStream = null;

try {

byteArrayOutputStream = new ByteArrayOutputStream();

gzipOutputStream = new GZIPOutputStream(byteArrayOutputStream);

gzipOutputStream.write(data);

gzipOutputStream.finish();

bytes = byteArrayOutputStream.toByteArray();

} finally {

}

return bytes;

}

/**

* 解压缩

* @param data

* @return

* @throws IOException

*/

public static byte[] unGZip(byte[] data) throws IOException {

byte[] bytes = null;

ByteArrayInputStream byteArrayInputStream = null;

GZIPInputStream gzipInputStream = null;

ByteArrayOutputStream byteArrayOutputStream = null;

try {

byteArrayInputStream = new ByteArrayInputStream(data);

gzipInputStream = new GZIPInputStream(byteArrayInputStream);

byte[] buf = new byte[1024];

int num = -1;

byteArrayOutputStream = new ByteArrayOutputStream();

while ((num = gzipInputStream.read(buf, 0, buf.length)) != -1)

{

byteArrayOutputStream.write(buf, 0, num);

}

bytes = byteArrayOutputStream.toByteArray();

byteArrayOutputStream.flush();

} finally {

byteArrayInputStream.close();

gzipInputStream.close();

byteArrayOutputStream.close();

}

return bytes;

}