１．获取APP当前目录路径：

public String getPath(){
        File fileDire = getFilesDir();//获取../data/应用的包名/files/ 目录
        File cacheDire = getCacheDir();//获取../data/应用的包名/files/ 目录
        String filePath  = fileDire.toString();
        String cachePath  = cacheDire.toString();
        String rootpath = filePath.substring(0,filePath.lastIndexOf("/")); //截取掉files   获取../data/应用的包名/
        return rootpath;
    }

2.创建文件：

public void creatFile(String path, String fileName) {
        File file = new File(path, fileName);
        try {
            if (!file.exists()) {
                file.createNewFile();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
   }

３．创建文件夹

public void creatFile(String path, String fileName) {
        File file = new File(path, fileName);
        try {
            if (!file.exists()) {
                file.createNewFile();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
 
    }

４．将assets下文件复制到指定目录下

首先在android studio 目录结构切换到project上来在src/main下new->folder->assets folder创建assets目录然后将文件放到此文件夹下。

public void copyfile(String filepath,String fileName,String assetsName) {
        try {
            if (!new File(filepath + "/" + fileName).exists()) {
 
                InputStream is = getResources().getAssets().open(assetsName);
 
                FileOutputStream fos = new FileOutputStream(filepath + "/" + fileName);
                byte[] buffer = new byte[7168];
                int count = 0;
                while ((count = is.read(buffer)) > 0) {
                    fos.write(buffer, 0, count);
                }
                fos.close();
                is.close();
            }
        } catch (IOException e){
            e.printStackTrace();
        }
    }