概述

想要随手写点东西感想之类的，或者一些临时的个人小心思，秘密啥的，又怕联网不安全，写一个纯本地的文件类型的小记事本，无数据库之类的乱七八糟的。也没有什么什么权限要去申请。

先上图

取得本地文件列表

private void getFileList() {
    
    
    File rootDir = new File(rootPath);
    if (!rootDir.exists()) {
    
    
        //android高版本都要动态申请权限，现在手机基本都是android5之后了
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    
    
            ActivityCompat.requestPermissions(this, new String[]{
    
    Manifest.permission.WRITE_EXTERNAL_STORAGE}, 100);
        }
    }
    lstFile.clear();
    File[] fList = rootDir.listFiles();
    if(fList != null && fList.length > 0){
    
    
        for(File file : fList){
    
    
            if(file.isDirectory()) continue;
            String suffix = file.getName().substring(file.getName().lastIndexOf('.'));
            if(suffix.equals(".zgn") || suffix.equals(".txt")){
    
    
                String filename = file.getName().substring(0, file.getName().lastIndexOf('.'));
                lstFile.add(new FileInfoModule(filename, file.getAbsolutePath(), file.lastModified()));
            }
        }
        Collections.sort(lstFile, (fileInfoModule, t1) -> String.valueOf(t1.getLastModified()).compareTo(String.valueOf(fileInfoModule.getLastModified())));
    }else{
    
    
        Pub.showMsgInfo(this, "找不到文件！");
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    
    
    //super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (requestCode == 100) {
    
    
        if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
    
    
            File rootDir = new File(rootPath);
            if(!rootDir.mkdirs()) Pub.showMsgInfo(this, "Note目录创建失败!");
        }
    }
}

点击列表跳转阅读界面

Intent intent = new Intent(this, NoteReadActivity.class);
Bundle bundle = new Bundle();
bundle.putString("filename", lstFile.get(i).getFileName());
bundle.putString("filepath", lstFile.get(i).getFielPath());
bundle.putString("lastmodified", new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(lstFile.get(i).getLastModified()));
intent.putExtras(bundle);
startActivity(intent);

根据文件路径读取文件内容

private String getFileContent(String filePath){
    
    
    if(filePath.equals("")) Pub.showMsgError(this,"文件路径为空！");
    try {
    
    
        File filename = new File(filePath);
        FileInputStream fin = new FileInputStream(filename);
        BufferedReader reader = new BufferedReader(new InputStreamReader(fin));
        String fileContent = "";
        String line = "";
        while ((line = reader.readLine()) !=null){
    
    
            fileContent = fileContent + line + "\n";
        }
        reader.close();
        fin.close();
        return fileContent;
    }catch (Exception e){
    
    
        Pub.showMsgError(this, e.getMessage());
    }
    return "";
}

保存文件

private void saveContent() {
    
    
    //如果标题为空，则生成当前日期的标题
    String filename = "";
    if (mView.etNoteeditTitle.getText().toString().equals("")) {
    
    
        filename = new SimpleDateFormat("yyyyMMdd").format(System.currentTimeMillis());
    } else filename = mView.etNoteeditTitle.getText().toString();
    File file = new File(filePath);
    if (file.isDirectory()) {
    
    
        file = new File(file.getPath(), filename + ".zgn");
        if (file.exists()) {
    
    
            filename = new SimpleDateFormat("yyyyMMdd-HHmmss").format(System.currentTimeMillis());
            file = new File(file.getParent(), filename + ".zgn");
        }
    } else {
    
    
        String oldfilename = file.getName().substring(0, file.getName().lastIndexOf('.'));
        if (!oldfilename.equals(filename)) {
    
    
            String parentpath = file.getParent();
            file.delete();
            file = new File(parentpath, filename + ".zgn");
        }
    }
    try {
    
    
        FileOutputStream fout = new FileOutputStream(file);
        fout.write(mView.etNoteeditContent.getText().toString().getBytes());
        fout.close();
        Intent intent = new Intent(this, NoteReadActivity.class);
        Bundle bundle = new Bundle();
        bundle.putString("filename", file.getName().substring(0, file.getName().lastIndexOf('.')));
        bundle.putString("filepath", file.getAbsolutePath());
        bundle.putString("lastmodified", new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(file.lastModified()));
        intent.putExtras(bundle);
        startActivityByAnim(intent);
        NoteEditActivity.this.finish();
    } catch (Exception e) {
    
    
        Pub.showMsgInfo(this, e.getMessage());
    }
}