合并流

最新推荐文章于 2023-01-29 20:06:03 发布

原创最新推荐文章于 2023-01-29 20:06:03 发布 · 362 阅读

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sequenceInputStream：

此流可以把多个文件合并在一起；比如文件太大的时候，如果采用下载的方式，可以先分割为多个文件，然后在合并起来就可以了；下面是简单的分割工具类与合并工具类：

分割工具类：

package com.tanghaibin.io;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.junit.Test;

public class SplitFileUtil {

public static void splitFile(String filePath, String splitFilePath) throws IOException{

  InputStream is = new FileInputStream(filePath);

  OutputStream os = null;

  byte [] buff = new byte[1024*100];

  int count = 0;

  while((is.read(buff))!=-1){

   ++count;

   os = new FileOutputStream(splitFilePath+File.separator+count+".file");

   os.write(buff);

  }

  if(os != null){

   os.close();

  }

  if(is != null){

   is.close();

  }
}

}

合并工具类：

package com.tanghaibin.io;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.SequenceInputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;

import org.junit.Test;

public class FileMergeUtil {

public static void fileMerge(String filePath, String mergePath) throws IOException{

  File file = new File(filePath);

  File [] file2 = file.listFiles();


  Collection list = new ArrayList();

  InputStream is = null;

  for(int i = 0; i < file2.length; ++i){

   is = new FileInputStream(filePath + File.separator+file2[i].getName());

   list.add(is);

  }

  Enumeration enumeration = Collections.enumeration(list);

  SequenceInputStream sis = new SequenceInputStream(enumeration);

  OutputStream os = new FileOutputStream(mergePath);

  byte [] buff = new byte[1024*1024];

  int len = 0;

  while((len = sis.read(buff))!=-1){

   os.write(buff,0,len);
  }

  if(os!=null){

   os.close();

  }

  if(is!=null){

   is.close();

  }

}