/**
     * 拆分的思路，先把原始檔的所有內容讀取到記憶體中，然後從記憶體中挨個分到子檔案裡
     *
     * @param srcFile
     *            要拆分的原始檔 路徑
     * @param eachSize
     *            按照這個大小，拆分 100 * 1024; // 100k
     */
    private static void splitFile(File srcFile, int eachSize) {

        if (0 == srcFile.length())
            throw
 
 new RuntimeException("檔案長度為0，不可拆分");

        byte[] fileContent = new byte[(int) srcFile.length()];
        // 為了在finally中關閉，需要宣告在try外面
        FileInputStream fis = null;
        try {
            fis = new FileInputStream(srcFile);
            fis.read(fileContent);

        } catch (IOException e) {

            e.printStackTrace();
        } finally
 
 {
            // 在finally中關閉
            try {
                if(null!=fis)
                    fis.close();
            } catch (IOException e) {

                e.printStackTrace();
            }
        }

        int fileNumber;
        if (0 == fileContent.length % eachSize)
            fileNumber = (int
 
) (fileContent.length / eachSize);
        else
            fileNumber = (int) (fileContent.length / eachSize) + 1;

        for (int i = 0; i < fileNumber; i++) {
            String eachFileName = srcFile.getName() + "-" + i;
            File eachFile = new File(srcFile.getParent(), eachFileName);
            byte[] eachContent;

            if (i != fileNumber - 1)
                eachContent = Arrays.copyOfRange(fileContent, eachSize * i, eachSize * (i + 1));
            else
                eachContent = Arrays.copyOfRange(fileContent, eachSize * i, fileContent.length);

            // 為了在finally中關閉，宣告在try外面
            FileOutputStream fos = null;
            try {
                fos = new FileOutputStream(eachFile);
                fos.write(eachContent);

                System.out.printf("輸出子檔案%s，其大小是%,d位元組%n", eachFile.getAbsoluteFile(), eachFile.length());
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                // finally中關閉
                try {
                    if(null!=fos)
                        fos.close();
                } catch (IOException e) {

                    e.printStackTrace();
                }
            }
        }

    }

    /**
     * 合併的思路，就是從eclipse.exe-0開始，讀取到一個檔案，就開始寫出到 eclipse.exe中，直到沒有檔案可以讀
     *
     * @param folder
     *            需要合併的檔案所處於的目錄
     * @param fileName
     *            需要合併的檔案的名稱
     * @throws FileNotFoundException
     */
    private static void murgeFile(String folder, String fileName) {

        File destFile = new File(folder, fileName);
        // 使用try-with-resource的方式自動關閉流
        try (FileOutputStream fos = new FileOutputStream(destFile);) {
            int index = 0;
            while (true) {
                File eachFile = new File(folder, fileName + "-" + index++);
                if (!eachFile.exists())
                    break;

                // 使用try-with-resource的方式自動關閉流
                try (FileInputStream fis = new FileInputStream(eachFile);) {
                    byte[] eachContent = new byte[(int) eachFile.length()];
                    fis.read(eachContent);
                    fos.write(eachContent);
                    fos.flush();
                }
                System.out.printf("把子檔案 %s寫出到目標檔案中%n", eachFile);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }

        System.out.printf("最後目標檔案的大小：%,d位元組", destFile.length());

    }

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