java基础学习笔记——I/O文件切割与合并

class SplitFileDemo 
{
	public static void main(String[] args) 
	{
		System.out.println("Hello World!");
	}

	public static void splitFile(File file)
	{
		FileInputStream fis = new FileInputStream(file);
		byte[] buf = new byte[1024*1024];

		FileOutputStream fos = null;

		int len = 0;
		int num = 1;

		Properties prop = new Properties();


		File dir = new File("c"\\partFile");
		if(!dir.exits())
			dir.madirs();
		while((len=fis.read(buf))!=-1)
		{
			fos = new FileOutputStream(new File(dir,num+".part"));
			num++;
			fos.write(buf,0,len);
			fos.close();
		}
		prop.setProperty("partcount",count+"");
		prop.setProperty("filename",file.getName());
		
		fos = new FileOutputStream(new File(dir,count+".properties"));
	    prop.store(fos,"sava file info");
		fis.close();
		
	}
}


public class MergeFile
{
	public static void mergeFile(File dir)
	{

		//获取指定目录下配置文件对象
		File[] files = dir.listFiles(new SufixFilter(".properties"));
		if(files.length!=1)
			throw new RuntimeException(dir+",该目录下没有或者不唯一.properties");
		//记录配置文件对象
		File confile = files[0];

		//获取该文件的信息
		Properties prop = new Properties();
		FileInputStream fis = new FileInputStream(confile);
		prop.load(fis);
		String filename = prop.getProperty("filename");
		int count = Integer.parseInt(prop.getProperty("partcount"));

		//获取该目录下的所有碎片文件
		File[] partFiles = dir.listFile(new SuffixFilter(".part"));
		if(partFiles.length!=(count-1))
			throw new  RuntimeException("碎片个数不对，应该有"+(count)+"个");

	//	ArrayList<FileInputStream> a1 = new ArrayList<FileInputStream>;
	//	for(int x=1;x<=3;x++)
		//将碎片文件和流对象关联并存储到集合中
	    ArrayList<FileInputStream> a1 = new ArrayList<FileInputStream>;
		for(int x=0;x<partFiles.length;x++)
		{
	//		a1.add(new FileInputStream(new File(dir,x+".part")));
			a1.add(new FileInputStream(partFiles[x]));
		}
		//将多个流合并成一个序列流
		Enueration<FileInputStream> em = Collection.enueration(a1);
		SequenceInputStream sis = new SequenceInputStream(em);
		FileOutputStream fos = new FileOutputStream(new File(dir,"1.txt"));
	
		byte[] buf = new byte[1024];
		int len = 0;
		while((len=sis.read(buf))!=-1)
		{
			fos.write(buf,0,len);
		}
		sis.close();
		fos.close();
	}
}

public class SuffixFilter implements FilenameFilter
{
	private String suffix;
	public SuffixFilter(String suffix)
	{
		super();
		this.suffix = suffix;
	}
	public boolean accept(File dir,String name)
	{
		return name.endsWidth(suffix);
	}
}