package com.mufeng.toolproject.utils;
import android.content.Context;
import android.content.res.AssetManager;
import android.text.TextUtils;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* Created by mufeng on 2017/3/12.
*/
public class FileStorageHelper {
private static final String SEPARATOR = File.separator;//路径分隔符
/**
* 复制assets中的文件到指定目录
*
* @param context 上下文
* @param assetsPath assets资源路径
* @param storagePath 目标文件夹的路径
*/
public static void copyFilesFromAssets(Context context, String assetsPath, String storagePath) {
String temp = "";
if (TextUtils.isEmpty(storagePath)) {
return;
} else if (storagePath.endsWith(SEPARATOR)) {
storagePath = storagePath.substring(0, storagePath.length() - 1);
}
if (TextUtils.isEmpty(assetsPath) || assetsPath.equals(SEPARATOR)) {
assetsPath = "";
} else if (assetsPath.endsWith(SEPARATOR)) {
assetsPath = assetsPath.substring(0, assetsPath.length() - 1);
}
AssetManager assetManager = context.getAssets();
try {
File file = new File(storagePath);
if (!file.exists()) {//如果文件夹不存在，则创建新的文件夹
file.mkdirs();
}
// 获取assets目录下的所有文件及目录名
String[] fileNames = assetManager.list(assetsPath);
if (fileNames.length > 0) {//如果是目录 apk
for (String fileName : fileNames) {
if (!TextUtils.isEmpty(assetsPath)) {
temp = assetsPath + SEPARATOR + fileName;//补全assets资源路径
}
String[] childFileNames = assetManager.list(temp);
if (!TextUtils.isEmpty(temp) && childFileNames.length > 0) {//判断是文件还是文件夹：如果是文件夹
copyFilesFromAssets(context, temp, storagePath + SEPARATOR + fileName);
} else {//如果是文件
InputStream inputStream = assetManager.open(temp);
readInputStream(storagePath + SEPARATOR + fileName, inputStream);
}
}
} else {//如果是文件 doc_test.txt或者apk/app_test.apk
InputStream inputStream = assetManager.open(assetsPath);
if (assetsPath.contains(SEPARATOR)) {//apk/app_test.apk
assetsPath = assetsPath.substring(assetsPath.lastIndexOf(SEPARATOR), assetsPath.length());
}
readInputStream(storagePath + SEPARATOR + assetsPath, inputStream);
}
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 读取输入流中的数据写入输出流
*
* @param storagePath 目标文件路径
* @param inputStream 输入流
*/
public static void readInputStream(String storagePath, InputStream inputStream) {
File file = new File(storagePath);
try {
if (!file.exists()) {
// 1.建立通道对象
FileOutputStream fos = new FileOutputStream(file);
// 2.定义存储空间
byte[] buffer = new byte[inputStream.available()];
// 3.开始读文件
int lenght = 0;
while ((lenght = inputStream.read(buffer)) != -1) {// 循环从输入流读取buffer字节
// 将Buffer中的数据写到outputStream对象中
fos.write(buffer, 0, lenght);
}
fos.flush();// 刷新缓冲区
// 4.关闭流
fos.close();
inputStream.close();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
在需要的地方调用上面的工具类：
FileStorageHelper.copyFilesFromAssets(this, "doc_test.txt", path + "/" + "a_mufeng");
// FileStorageHelper.copyFilesFromAssets(this, "apk", path + "/" + "a_mufeng");
// FileStorageHelper.copyFilesFromAssets(this, "apk/app_test.apk", path + "/" + "a_mufeng");
assets的目录结构
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