1、首先需要给应用配置权限才可以在存储卡创建文件，配置参照：

Android 在存储卡(sdcard)创建文件夹/文件失败

2、代码：

public void copyTo(String fromPath, String toPath){
	//	复制位置
	//	opPath：mnt/sdcard/lcuhg/health/
	//	mnt/sdcard：表示sdcard
	File toFile = new File(toPath);
	//	如果不存在，创建文件夹
	if(!toFile.exists()){
		boolean isCreate = toFile.mkdirs();
		//	打印创建结果
		Log.i("create dir", String.valueOf(isCreate));
	}
	
	try {
		//	根据文件名获取assets文件夹下的该文件的inputstream
		InputStream fromFileIs = context.getResources().getAssets().open(fromPath);
		int length = fromFileIs.available();	//获取文件的字节数
        byte[] buffer = new byte[length];	//创建byte数组
        FileOutputStream fileOutputStream = new FileOutputStream(toFile+"/zhike.zip");	//字节输入流
        BufferedInputStream bufferedInputStream = new BufferedInputStream(fromFileIs);
        BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(fileOutputStream);
        int len = bufferedInputStream.read(buffer);
        while(len != -1){
        	bufferedOutputStream.write(buffer, 0, len);
        	len = bufferedInputStream.read(buffer);
        }
        bufferedInputStream.close();
        bufferedOutputStream.close();
        fromFileIs.close();
        fileOutputStream.close();
	} catch (Exception e) {
		e.printStackTrace();
	}
	
}