文件读写等操作

                                              文件相关操作

1、读文件，一行一行的读

public static void readFile(File file) {
        InputStream instream = null;
        try {
            instream = new FileInputStream(file);

            if (instream != null) {
                InputStreamReader inputreader = new InputStreamReader(instream);
                BufferedReader buffreader = new BufferedReader(inputreader);

                String line;

                //分行读取
                while ((line = buffreader.readLine()) != null) {
                    Log.d("readFile: line str = ", line);
                }
            }
        } catch (java.io.FileNotFoundException e) {
            Log.d("readFile", "The File doesn't exist.");
        } catch (IOException e) {
            Log.d("readFile", e.getMessage());
        } finally {
            try {
                if (instream != null) {
                    instream.close();
                }
            } catch (IOException e) {

            }
        }
    }

2、一行一行的写

private void writeFile(File file) {
        FileOutputStream fileOutputStream = null;

        try {
            fileOutputStream = new FileOutputStream(file);
            List<String> strList = new ArrayList<>();

            strList.add("string 1");
            strList.add("string 2");
            strList.add("string 3");
            strList.add("string 4");
            strList.add("string 5");
            strList.add("string 6");

            for (String str : strList) {
                String writeLine = str + "\n";
                fileOutputStream.write(writeLine.getBytes());
            }
        } catch (java.io.FileNotFoundException e) {

        } catch (IOException e) {
            Log.d(TAG, "writeFile" + e.getMessage());
        } finally {
            try {
                if (fileOutputStream != null) {
                    fileOutputStream.close();
                }
            } catch (IOException e) {

            }
        }
    }

3、文件拷贝

public static void copyFolder(String srcDir, String destDir) {
        Log.d("wujiang", "copyFolder: srcDir = " + srcDir);
        Log.d("wujiang", "copyFolder: destDir = " + destDir);

        try {
            File destFile = new File(destDir);
            if (destFile.exists()) {
                destFile.delete();
            }

            destFile.mkdir();

            File srcFile = new File(srcDir);
            String[] files = srcFile.list();
            File temp;

            for(String file : files) {
                Log.d(TAG, "copyFolder: file = " + file);
                if (srcDir.endsWith(File.separator)) {
                    temp = new File(srcDir + file);
                } else {
                    temp = new File(srcDir + File.separator + file);
                }

                if (temp.isDirectory()) {   //如果是子文件夹
                    copyFolder(srcDir + File.separator + file, destDir + File.separator + file);
                } else if (!temp.exists()) {
                    Log.e(TAG, "copyFolder: oldFile not exist.");
                    return;
                } else if (!temp.isFile()) {
                    Log.e(TAG, "copyFolder: oldFile not file.");
                    return;
                } else if (!temp.canRead()) {
                    Log.e(TAG, "copyFolder: oldFile cannot read.");
                    return;
                } else {
                    FileInputStream fileInputStream = new FileInputStream(temp);
                    FileOutputStream fileOutputStream = new FileOutputStream(destDir + File.separator + temp.getName());
                    byte[] buffer = new byte[1024];
                    int byteRead;
                    while ((byteRead = fileInputStream.read(buffer)) != -1) {
                        fileOutputStream.write(buffer, 0, byteRead);
                    }
                    fileInputStream.close();
                    fileOutputStream.flush();
                    fileOutputStream.close();
                }
            }

        } catch (Exception e) {
            Log.e(TAG, "error msg: " + e.getMessage());
        } finally {

        }
    }