视频预加载
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张玉久
206
app/src/main/java/com/gh/download/cache/CacheManager.java
vendored
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206
app/src/main/java/com/gh/download/cache/CacheManager.java
vendored
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package com.gh.download.cache;
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import com.danikula.videocache.file.FileNameGenerator;
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import com.danikula.videocache.file.Md5FileNameGenerator;
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import com.halo.assistant.HaloApp;
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import com.shuyu.gsyvideoplayer.utils.StorageUtils;
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import java.io.File;
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import java.io.FileOutputStream;
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import java.io.IOException;
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import java.io.InputStream;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.HashMap;
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import java.util.List;
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import java.util.concurrent.atomic.AtomicReference;
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import io.reactivex.Observable;
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import io.reactivex.ObservableEmitter;
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import io.reactivex.ObservableOnSubscribe;
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import io.reactivex.android.schedulers.AndroidSchedulers;
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import io.reactivex.schedulers.Schedulers;
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import okhttp3.Call;
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import okhttp3.OkHttpClient;
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import okhttp3.Request;
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import okhttp3.Response;
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public class CacheManager {
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private static final AtomicReference<CacheManager> INSTANCE = new AtomicReference<>();
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private HashMap<String, Call> downCalls;
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private OkHttpClient mClient;
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private File cacheDirectory = StorageUtils.getIndividualCacheDirectory(HaloApp.getInstance().getApplication());
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private FileNameGenerator generator = new Md5FileNameGenerator();
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private final String TEMP_POSTFIX = ".download";
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private final int preLength = 5 * 1024 * 1024;//预加载大小
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public static CacheManager getInstance() {
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for (; ; ) {
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CacheManager current = INSTANCE.get();
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if (current != null) {
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return current;
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}
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current = new CacheManager();
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if (INSTANCE.compareAndSet(null, current)) {
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return current;
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}
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}
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}
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private CacheManager() {
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downCalls = new HashMap<>();
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mClient = new OkHttpClient.Builder().build();
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}
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public void download(String url, CacheObserver cacheObserver) {
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//当前url已下载完成则不再下载
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for (File file : getAllFile()) {
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if (file.getName().equals(generator.generate(url))) {
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return;
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}
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}
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Observable.just(url)
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.filter(s -> !downCalls.containsKey(s))//call的map已经有了,就证明正在下载,则这次不下载
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.flatMap(s -> Observable.just(createDownInfo(s)))
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.map(this::getRealFileName)
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.flatMap(cacheInfo -> Observable.create(new DownloadSubscribe(cacheInfo)))
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.observeOn(AndroidSchedulers.mainThread())
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.subscribeOn(Schedulers.io())
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.subscribe(cacheObserver);
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}
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public void cancel(String url) {
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Call call = downCalls.get(url);
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if (call != null) {
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call.cancel();
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}
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downCalls.remove(url);
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}
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/**
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* 创建DownInfo
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*
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* @param url 请求网址
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* @return DownInfo
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*/
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private CacheInfo createDownInfo(String url) {
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CacheInfo cacheInfo = new CacheInfo(url);
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long contentLength = getContentLength(url);//获得文件大小
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cacheInfo.setTotal(contentLength);
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String fileName = generator.generate(url) + TEMP_POSTFIX;
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cacheInfo.setFileName(fileName);
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return cacheInfo;
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}
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private CacheInfo getRealFileName(CacheInfo cacheInfo) {
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String fileName = cacheInfo.getFileName();
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long downloadLength = 0;
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if (!cacheDirectory.exists()) {
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cacheDirectory.mkdir();
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}
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File file = new File(cacheDirectory, fileName);
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if (file.exists()) {
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//找到了文件,代表已经下载过,则获取其长度
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downloadLength = file.length();
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}
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//设置改变过的文件名/大小
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cacheInfo.setProgress(downloadLength);
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cacheInfo.setFileName(file.getName());
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return cacheInfo;
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}
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private class DownloadSubscribe implements ObservableOnSubscribe<CacheInfo> {
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private CacheInfo cacheInfo;
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public DownloadSubscribe(CacheInfo cacheInfo) {
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this.cacheInfo = cacheInfo;
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}
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@Override
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public void subscribe(ObservableEmitter<CacheInfo> e) throws Exception {
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String url = cacheInfo.getUrl();
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long downloadLength = cacheInfo.getProgress();//已经下载好的长度
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long contentLength = cacheInfo.getTotal();//文件的总长度
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if (downloadLength >= preLength) {
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e.onComplete();
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return;
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}
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e.onNext(cacheInfo);
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Request request = new Request.Builder()
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.addHeader("RANGE", "bytes=" + downloadLength + "-" + (contentLength > preLength ? preLength : contentLength))
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.url(url)
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.build();
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Call call = mClient.newCall(request);
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downCalls.put(url, call);
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Response response = call.execute();
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File file = new File(cacheDirectory, cacheInfo.getFileName());
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InputStream is = null;
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FileOutputStream fileOutputStream = null;
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try {
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is = response.body().byteStream();
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fileOutputStream = new FileOutputStream(file, true);
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byte[] buffer = new byte[2048];
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int len;
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while ((len = is.read(buffer)) != -1) {
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fileOutputStream.write(buffer, 0, len);
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downloadLength += len;
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cacheInfo.setProgress(downloadLength);
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e.onNext(cacheInfo);
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}
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fileOutputStream.flush();
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downCalls.remove(url);
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} finally {
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if (is != null) {
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is.close();
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}
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if (fileOutputStream != null) {
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fileOutputStream.close();
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}
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}
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if (file.length() == contentLength){
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file.renameTo(new File(file.getPath().substring(0,file.getPath().lastIndexOf(TEMP_POSTFIX))));
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}
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e.onComplete();
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}
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}
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/**
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* 获取下载长度
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*
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* @param downloadUrl
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* @return
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*/
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private long getContentLength(String downloadUrl) {
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Request request = new Request.Builder()
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.url(downloadUrl)
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.build();
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try {
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Response response = mClient.newCall(request).execute();
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if (response != null && response.isSuccessful()) {
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long contentLength = response.body().contentLength();
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response.close();
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return contentLength == 0 ? CacheInfo.TOTAL_ERROR : contentLength;
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}
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} catch (IOException e) {
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e.printStackTrace();
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}
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return CacheInfo.TOTAL_ERROR;
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}
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public void removeAllCall() {
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for (String key : downCalls.keySet()) {
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cancel(key);
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}
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}
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private List<File> getAllFile() {
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if (cacheDirectory.exists()) {
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File[] files = cacheDirectory.listFiles();
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return Arrays.asList(files);
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}
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return new ArrayList<>();
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}
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}
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