import org.junit.Test;

import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

/**
 * @author Administrator
 * @version 1.0
 **/
public class TestFile {



    //測試檔案分塊
    @Test
    public void testChunk() throws IOException {
        //原始檔
        File sourceFile = new File("D:\\lucene.avi");
        //塊檔案目錄
        String chunkFileFolder = "D:\\chunks";

        //先定義塊檔案大小
        long chunkFileSize = 1 * 1024 * 1024;

        //塊數
        long chunkFileNum = (long) Math.ceil(sourceFile.length() * 1.0 /chunkFileSize);

        //建立讀檔案的物件
        RandomAccessFile raf_read = new RandomAccessFile(sourceFile,"r");

        //緩衝區
        byte[] b = new byte[1024];
        for(int i=0;i<chunkFileNum;i++){
            //塊檔案
            File chunkFile = new File(chunkFileFolder+i);
            //建立向塊檔案的寫物件
            RandomAccessFile raf_write = new RandomAccessFile(chunkFile,"rw");
            int len = -1;

            while((len = raf_read.read(b))!=-1){

                raf_write.write(b,0,len);
                //如果塊檔案的大小達到 1M開始寫下一塊兒
                if(chunkFile.length()>=chunkFileSize){
                    break;
                }
            }
            raf_write.close();


        }
        raf_read.close();
    }


    //測試檔案合併
    @Test
    public void testMergeFile() throws IOException {
        //塊檔案目錄
        String chunkFileFolderPath = "D:\\chunks";
        //塊檔案目錄物件
        File chunkFileFolder = new File(chunkFileFolderPath);
        //塊檔案列表
        File[] files = chunkFileFolder.listFiles();
        //將塊檔案排序，按名稱升序
        List<File> fileList = Arrays.asList(files);
        Collections.sort(fileList, new Comparator<File>() {
            @Override
            public int compare(File o1, File o2) {
                if(Integer.parseInt(o1.getName())>Integer.parseInt(o2.getName())){
                    return 1;
                }
                return -1;
            }
        });

        //合併檔案
        File mergeFile = new File("D:\\lucene_merge.avi");
        //建立新檔案
        boolean newFile = mergeFile.createNewFile();

        //建立寫物件
        RandomAccessFile raf_write = new RandomAccessFile(mergeFile,"rw");

        byte[] b = new byte[1024];
        for(File chunkFile:fileList){
            //建立一個讀塊檔案的物件
            RandomAccessFile raf_read = new RandomAccessFile(chunkFile,"r");
            int len = -1;
            while((len = raf_read.read(b))!=-1){
                raf_write.write(b,0,len);
            }
            raf_read.close();
        }
        raf_write.close();
    }
}