Package org.miaixz.bus.core.io.copier

Class FileChannelCopier

java.lang.Object

org.miaixz.bus.core.io.copier.IoCopier<FileChannel,FileChannel>

org.miaixz.bus.core.io.copier.FileChannelCopier

public class FileChannelCopier
extends IoCopier<FileChannel,FileChannel>

FileChannel 数据拷贝封装

 FileChannel#transferTo 或 FileChannel#transferFrom 的实现是平台相关的，需要确保低版本平台的兼容性
 例如 android 7以下平台在使用 ZipInputStream 解压文件的过程中，
 通过 FileChannel#transferFrom 传输到文件时，其返回值可能小于 totalBytes，不处理将导致文件内容缺失

 // 错误写法，dstChannel.transferFrom 返回值小于 zipEntry.getSize()，导致解压后文件内容缺失
 try (InputStream srcStream = zipFile.getInputStream(zipEntry);
     ReadableByteChannel srcChannel = Channels.newChannel(srcStream);
     FileOutputStream fos = new FileOutputStream(saveFile);
     FileChannel dstChannel = fos.getChannel()) {
     dstChannel.transferFrom(srcChannel, 0, zipEntry.getSize());
  }
 

Since:

Java 17+

Author:

Kimi Liu

Field Summary

Fields inherited from class org.miaixz.bus.core.io.copier.IoCopier

bufferSize, count, flushEveryBuffer, progress

Constructor Summary

Constructors

Constructor	Description
FileChannelCopier(long count)	构造

Method Summary

Modifier and Type	Method	Description
long	copy(FileInputStream in, FileOutputStream out)	拷贝文件流，使用NIO
long	copy(FileChannel source, FileChannel target)	执行拷贝
static FileChannelCopier	of()	创建FileChannel 拷贝器
static FileChannelCopier	of(long count)	创建FileChannel 拷贝器

Methods inherited from class org.miaixz.bus.core.io.copier.IoCopier

bufferSize, setFlushEveryBuffer

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

FileChannelCopier

public FileChannelCopier(long count)

构造

Parameters:

count - 拷贝总数，-1表示无限制

Method Details

of

public static FileChannelCopier of()

创建FileChannel 拷贝器

Returns:

FileChannelCopier

of

public static FileChannelCopier of(long count)

创建FileChannel 拷贝器

Parameters:

count - 拷贝总数，-1表示无限制

Returns:

FileChannelCopier

copy

public long copy(FileInputStream in,
 FileOutputStream out)
          throws InternalException

拷贝文件流，使用NIO

Parameters:

in - 输入

out - 输出

Returns:

拷贝的字节数

Throws:

InternalException - IO异常

copy

public long copy(FileChannel source,
 FileChannel target)

Description copied from class: IoCopier

执行拷贝

Specified by:

copy in class IoCopier<FileChannel,FileChannel>

Parameters:

source - 拷贝源，如InputStream、Reader等

target - 拷贝目标，如OutputStream、Writer等

Returns:

拷贝的实际长度