Android文件下载 Android实现文件下载
厚积沉积 人气:1想了解Android实现文件下载的相关内容吗，厚积沉积在本文为您仔细讲解Android文件下载的相关知识和一些Code实例，欢迎阅读和指正，我们先划重点：Android,文件下载，下面大家一起来学习吧。
前言
总体思路：下载文件到应用缓存路径，在相册创建文件夹，Copy过去，通知相册刷新。
下载文件到APP缓存路径，这样可避免Android高版本读取本地权限问题，
准备
implementation 'com.squareup.okhttp3:okhttp:3.6.0' implementation 'com.squareup.okio:okio:1.11.0'
调用
url：文件url
path：储存的路径
应用缓存路径：getExternalCacheDir().getPath()
DownloadUtil.get().download(url, path, new DownloadUtil.OnDownloadListener() {
@Override
public void onDownloadSuccess(File file) {
//下载成功
handler.sendEmptyMessage(1);
}
@Override
public void onDownloading(int progress) {
//进度条
handler.sendEmptyMessage(progress);
}
@Override
public void onDownloadFailed() {
//下载失败
handler.sendEmptyMessage(-1);
}
});
复制到相册目录
DownloadUtil.createFiles(downLoadFile);
通知相册刷新
DownloadUtil.updateDCIM(this,downloadFile);
工具类
/**
* 下载工具类
* martin
* 2021.7.21
*/
public class DownloadUtil {
private static final String TAG = DownloadUtil.class.getName();
private static DownloadUtil downloadUtil;
private final OkHttpClient okHttpClient;
public static DownloadUtil get() {
if (downloadUtil == null) {
downloadUtil = new DownloadUtil();
}
return downloadUtil;
}
private DownloadUtil() {
okHttpClient = new OkHttpClient();
}
/**
* 复制单个文件
*
* @param oldPath$Name String 原文件路径+文件名 如：data/user/0/com.test/files/abc.txt
* @param newPath$Name String 复制后路径+文件名 如：data/user/0/com.test/cache/abc.txt
* @return <code>true</code> if and only if the file was copied;
* <code>false</code> otherwise
*/
public static boolean copyFile(String oldPath$Name, String newPath$Name) {
try {
File oldFile = new File(oldPath$Name);
if (!oldFile.exists()) {
Log.e("--Method--", "copyFile: oldFile not exist.");
return false;
} else if (!oldFile.isFile()) {
Log.e("--Method--", "copyFile: oldFile not file.");
return false;
} else if (!oldFile.canRead()) {
Log.e("--Method--", "copyFile: oldFile cannot read.");
return false;
}
/* 如果不需要打log，可以使用下面的语句
if (!oldFile.exists() || !oldFile.isFile() || !oldFile.canRead()) {
return false;
}
*/
FileInputStream fileInputStream = new FileInputStream(oldPath$Name);
FileOutputStream fileOutputStream = new FileOutputStream(newPath$Name);
byte[] buffer = new byte[1024];
int byteRead;
while (-1 != (byteRead = fileInputStream.read(buffer))) {
fileOutputStream.write(buffer, 0, byteRead);
}
fileInputStream.close();
fileOutputStream.flush();
fileOutputStream.close();
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
}
}
/**
* 通知相册更新
*
* @param context
* @param newFile
*/
public void updateDCIM(Context context, File newFile) {
File cameraPath = new File(dcimPath, "Camera");
File imgFile = new File(cameraPath, newFile.getAbsolutePath());
if (imgFile.exists()) {
Uri uri = Uri.fromFile(imgFile);
Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
intent.setData(uri);
context.sendBroadcast(intent);
}
}
/**
* url 下载连接
* saveDir 储存下载文件的SDCard目录
* listener 下载监听
*/
public void download(final String url, final String saveDir,
final OnDownloadListener listener) {
Request request = new Request.Builder().url(url).build();
okHttpClient.newCall(request).enqueue(new Callback() {
@Override
public void onFailure(Call call, IOException e) {
// 下载失败
listener.onDownloadFailed();
}
@Override
public void onResponse(Call call, Response response) throws IOException {
InputStream is = null;
byte[] buf = new byte[2048];
int len = 0;
FileOutputStream fos = null;
// 储存下载文件的目录
String savePath = isExistDir(saveDir);
try {
is = response.body().byteStream();
long total = response.body().contentLength();
File file = new File(savePath, getNameFromUrl(url));
fos = new FileOutputStream(file);
long sum = 0;
while ((len = is.read(buf)) != -1) {
fos.write(buf, 0, len);
sum += len;
int progress = (int) (sum * 1.0f / total * 100);
// 下载中
listener.onDownloading(progress);
}
fos.flush();
// 下载完成
listener.onDownloadSuccess(file);
} catch (Exception e) {
listener.onDownloadFailed();
} finally {
try {
if (is != null)
is.close();
} catch (IOException e) {
}
try {
if (fos != null)
fos.close();
} catch (IOException e) {
}
}
}
});
}
/**
* saveDir
* 判断下载目录是否存在
*/
private static String isExistDir(String saveDir) throws IOException {
// 下载位置
File downloadFile = new File(saveDir);
if (!downloadFile.mkdirs()) {
downloadFile.createNewFile();
}
String savePath = downloadFile.getAbsolutePath();
return savePath;
}
//系统相册路径
static String dcimPath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM).getAbsolutePath();
/**
* 创建文件夹
*/
public static void createFiles(File oldFile) {
try {
File file = new File(isExistDir(dcimPath + "/xxx"));
String newPath = file.getPath() + "/" + oldFile.getName();
Log.d("TAG", "createFiles111: " + oldFile.getPath() + "--" + newPath);
if (copyFile(oldFile.getPath(), newPath)) {
Log.d("TAG", "createFiles222: " + oldFile.getPath() + "--" + newPath);
}
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* url
* 从下载连接中解析出文件名
*/
@NonNull
public static String getNameFromUrl(String url) {
return url.substring(url.lastIndexOf("/") + 1);
}
public interface OnDownloadListener {
/**
* 下载成功
*/
void onDownloadSuccess(File file);
/**
* @param progress 下载进度
*/
void onDownloading(int progress);
/**
* 下载失败
*/
void onDownloadFailed();
}
}
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