标签：url void 监听 client Override new Glide4 public 加载
前言
我们都知道，使用Glide来加载一张网络上的图片是非常简单的，但是让人头疼的是，我们却无从得知当前图片的下载进度。如果这张图片很小的话，那么问题也不大，反正很快就会被加载出来。但如果这是一张比较大的GIF图，用户耐心等了很久结果图片还没显示出来，这个时候你就会觉得下载进度功能是十分有必要的了。
实现思路如下
我们知道Glide内部HTTP通讯组件的底层实现是基于HttpUrlConnection来进行定制的。但是HttpUrlConnection的可扩展性比较有限，我们在它的基础之上无法实现监听下载进度的功能，因此我们可以将Glide中的HTTP通讯组件替换成OkHttp，然后利用OkHttp强大的拦截器机制，通过向OkHttp中添加一个自定义的拦截器，就可以在拦截器中捕获到整个HTTP的通讯过程，然后加入一些自己的逻辑来计算下载进度，这样就可以实现下载进度监听的功能了。
0，首先添加依赖
dependencies {
compile 'com.github.bumptech.glide:glide:4.7.1'
annotationProcessor 'com.github.bumptech.glide:compiler:4.7.1'
}
添加依赖时如果报错，尝试解决如下，在Project的build.gradle文件中添加仓库：
allprojects {
repositories {
jcenter()
//需要添加的部分
maven { url "https://maven.google.com"}
}
}
在添加依赖时，相比于Glide 3，这里多添加了一个compiler的库，这个库是用于生成Generated API的，有了它我们就可以完全使用Glide3的语法来书写代码了，不同的是需要使用GlideApp去调用。
1，将OkHttpUrlLoader添加到项目：
/**
* A simple model loader for fetching media over http/https using OkHttp.
*/
public class OkHttpUrlLoader implements ModelLoader<GlideUrl, InputStream> {
private final Call.Factory client;
// Public API.
@SuppressWarnings("WeakerAccess")
public OkHttpUrlLoader(Call.Factory client) {
this.client = client;
}
@Override
public boolean handles(GlideUrl url) {
return true;
}
@Override
public LoadData<InputStream> buildLoadData(GlideUrl model, int width, int height,
Options options) {
return new LoadData<>(model, new OkHttpStreamFetcher(client, model));
}
/**
* The default factory for {@link OkHttpUrlLoader}s.
*/
// Public API.
@SuppressWarnings("WeakerAccess")
public static class Factory implements ModelLoaderFactory<GlideUrl, InputStream> {
private static volatile Call.Factory internalClient;
private final Call.Factory client;
private static Call.Factory getInternalClient() {
if (internalClient == null) {
synchronized (Factory.class) {
if (internalClient == null) {
internalClient = new OkHttpClient();
}
}
}
return internalClient;
}
/**
* Constructor for a new Factory that runs requests using a static singleton client.
*/
public Factory() {
this(getInternalClient());
}
/**
* Constructor for a new Factory that runs requests using given client.
*
* @param client this is typically an instance of {@code OkHttpClient}.
*/
public Factory(Call.Factory client) {
this.client = client;
}
@Override
public ModelLoader<GlideUrl, InputStream> build(MultiModelLoaderFactory multiFactory) {
return new OkHttpUrlLoader(client);
}
@Override
public void teardown() {
// Do nothing, this instance doesn't own the client.
}
}
}
2，将OkHttpStreamFetcher添加到项目：
/**
* Fetches an {@link InputStream} using the okhttp library.
*/
public class OkHttpStreamFetcher implements DataFetcher<InputStream>,
okhttp3.Callback {
private static final String TAG = "OkHttpFetcher";
private final Call.Factory client;
private final GlideUrl url;
@SuppressWarnings("WeakerAccess")
@Synthetic
InputStream stream;
@SuppressWarnings("WeakerAccess")
@Synthetic
ResponseBody responseBody;
private volatile Call call;
private DataCallback<? super InputStream> callback;
// Public API.
@SuppressWarnings("WeakerAccess")
public OkHttpStreamFetcher(Call.Factory client, GlideUrl url) {
this.client = client;
this.url = url;
}
@Override
public void loadData(Priority priority, final DataCallback<? super InputStream> callback) {
Request.Builder requestBuilder = new Request.Builder().url(url.toStringUrl());
for (Map.Entry<String, String> headerEntry : url.getHeaders().entrySet()) {
String key = headerEntry.getKey();
requestBuilder.addHeader(key, headerEntry.getValue());
}
Request request = requestBuilder.build();
this.callback = callback;
call = client.newCall(request);
if (Build.VERSION.SDK_INT != Build.VERSION_CODES.O) {
call.enqueue(this);
} else {
try {
// Calling execute instead of enqueue is a workaround for #2355, where okhttp throws a
// ClassCastException on O.
onResponse(call, call.execute());
} catch (IOException e) {
onFailure(call, e);
} catch (ClassCastException e) {
// It's not clear that this catch is necessary, the error may only occur even on O if
// enqueue is used.
onFailure(call, new IOException("Workaround for framework bug on O", e));
}
}
}
@Override
public void onFailure(@NonNull Call call, @NonNull IOException e) {
if (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, "OkHttp failed to obtain result", e);
}
callback.onLoadFailed(e);
}
@Override
public void onResponse(@NonNull Call call, @NonNull Response response) throws IOException {
responseBody = response.body();
if (response.isSuccessful()) {
long contentLength = Preconditions.checkNotNull(responseBody).contentLength();
stream = ContentLengthInputStream.obtain(responseBody.byteStream(), contentLength);
callback.onDataReady(stream);
} else {
callback.onLoadFailed(new HttpException(response.message(), response.code()));
}
}
@Override
public void cleanup() {
try {
if (stream != null) {
stream.close();
}
} catch (IOException e) {
// Ignored
}
if (responseBody != null) {
responseBody.close();
}
callback = null;
}
@Override
public void cancel() {
Call local = call;
if (local != null) {
local.cancel();
}
}
@NonNull
@Override
public Class<InputStream> getDataClass() {
return InputStream.class;
}
@NonNull
@Override
public DataSource getDataSource() {
return DataSource.REMOTE;
}
}
3，自定义拦截器：
public class ProgressInterceptor implements Interceptor{
public static final Map<String, ProgressListener> LISTENER_MAP = new HashMap<>();
public static void addListener(String url, ProgressListener listener) {
LISTENER_MAP.put(url, listener);
}
public static void removeListener(String url) {
LISTENER_MAP.remove(url);
}
@Override
public Response intercept(Chain chain) throws IOException {
Request request = chain.request();
Response response = chain.proceed(request);
String url = request.url().toString();
ResponseBody body = response.body();
Response newResponse = response.newBuilder().body(new ProgressResponseBody(url, body)).build();
return newResponse;
}
}
4，自定义回调接口：
public interface ProgressListener {
void onProgress(int progress);
}
5，计算加载进度，并在自定义的拦截器中使用：
public class ProgressResponseBody extends ResponseBody {
private static final String TAG = "ProgressResponseBody";
private BufferedSource bufferedSource;
private ResponseBody responseBody;
private ProgressListener listener;
public ProgressResponseBody(String url, ResponseBody responseBody) {
this.responseBody = responseBody;
listener = ProgressInterceptor.LISTENER_MAP.get(url);
}
@Override
public MediaType contentType() {
return responseBody.contentType();
}
@Override
public long contentLength() {
return responseBody.contentLength();
}
@Override
public BufferedSource source() {
if (bufferedSource == null) {
bufferedSource = Okio.buffer(new ProgressSource(responseBody.source()));
}
return bufferedSource;
}
private class ProgressSource extends ForwardingSource {
long totalBytesRead = 0;
int currentProgress;
ProgressSource(Source source) {
super(source);
}
@Override
public long read(Buffer sink, long byteCount) throws IOException {
long bytesRead = super.read(sink, byteCount);
long fullLength = responseBody.contentLength();
if (bytesRead == -1) {
totalBytesRead = fullLength;
} else {
totalBytesRead += bytesRead;
}
int progress = (int) (100f * totalBytesRead / fullLength);
Log.d(TAG, "download progress is " + progress);
if (listener != null && progress != currentProgress) {
listener.onProgress(progress);
}
if (listener != null && totalBytesRead == fullLength) {
listener = null;
}
currentProgress = progress;
return bytesRead;
}
}
}
6，自定义一个MyGlideModel，来继承AppGlideModule：
@GlideModule
public class MyGlideModel extends AppGlideModule {
public MyGlideModel() {
super();
}
@Override
public boolean isManifestParsingEnabled() {
return super.isManifestParsingEnabled();
}
@Override
public void applyOptions(@NonNull Context context, @NonNull GlideBuilder builder) {
super.applyOptions(context, builder);
}
@Override
public void registerComponents(@NonNull Context context, @NonNull Glide glide, @NonNull Registry registry) {
// super.registerComponents(context,glide,registry);
OkHttpClient okHttpClient = new OkHttpClient.Builder()
.addInterceptor(new ProgressInterceptor())
.build();
registry.replace(GlideUrl.class, InputStream.class, new OkHttpUrlLoader.Factory(okHttpClient));
}
}
然后在Android Studio中点击菜单栏Build -> Rebuild Project，GlideApp这个类就会自动生成了。
7，项目中使用：
public class Glide4Activity extends BaseActivity {
private static final String TAG = "Glide4Activity";
String imgUrl = "http://img5.adesk.com/5ab8ce65e7bce736a953c83c?imageMogr2/thumbnail/!720x1280r/gravity/Center/crop/720x1280";
@BindView(R.id.glide_iv)
ImageView mGlideIv;
ProgressDialog progressDialog;
@Override
public int getLayoutId() {
return R.layout.activity_glide;
}
@Override
public void initView() {
progressDialog = new ProgressDialog(this);
progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
progressDialog.setMessage("加载中");
ProgressInterceptor.addListener(imgUrl, new ProgressListener() {
@Override
public void onProgress(int progress) {
Log.d(TAG, "onProgress: " + progress);
progressDialog.setProgress(progress);
}
});
SimpleTarget<Drawable> simpleTarge = new SimpleTarget<Drawable>() {
@Override
public void onResourceReady(@NonNull Drawable resource, @Nullable Transition<? super Drawable> transition) {
progressDialog.dismiss();
mGlideIv.setImageDrawable(resource);
Log.d(TAG, "onResourceReady: ");
ProgressInterceptor.removeListener(imgUrl);
}
@Override
public void onStart() {
super.onStart();
Log.d(TAG, "onStart: ");
progressDialog.show();
}
};
GlideApp.with(this)
.load(imgUrl)
.diskCacheStrategy(DiskCacheStrategy.NONE)//不使用缓存
.skipMemoryCache(true)
.into(simpleTarge);
}
}
关于进度条的设置可参考另一篇博文：自定义progress之三种风格的图片加载进度显示样式
标签：url,void,监听,client,Override,new,Glide4,public,加载 来源： https://blog.csdn.net/gpf1320253667/article/details/95049226
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