关于picasso中的OkHttpDownloader类中引用okhttp，在okhttp3中的错误

在使用Picasso和okhttp这些开源的框架时，由于okttp已经升级到okhttp3，同时okhttp3的包名也随之改变了，从

com.squareup.okhttp变成了okhttp3 。

而Picasso中的OkHttpDownloader引用的包名还是

com.squareup.okhttp 这个包名。

所以在修改Picasso的图片缓存路劲时，即使用该段代码

Picasso picasso = Picasso.Builder(context).downloader(
OkhttpDownLoader(getDiskCacheDir(context))).build();

时，就会报错，无法使用。

解决法1：

不升级到okhttp3。

解决方法2：

自己写一个

OkhttpDownLoader

工具类。即修改上面那个类的代码，代码如下：

public class MyOkhttpDownLoader implements Downloader {
private static final int MIN_DISK_CACHE_SIZE = 5 * 1024 * 1024; // 5MB
private static final int DEFAULT_CONNECT_TIMEOUT_MILLIS = 15 * 1000; // 15s
private static final int DEFAULT_READ_TIMEOUT_MILLIS = 20 * 1000; // 20s
private static final int DEFAULT_WRITE_TIMEOUT_MILLIS = 20 * 1000; // 20s
private static final int MAX_DISK_CACHE_SIZE = 50 * 1024 * 1024; // 50MB

private static final String PICASSO_CACHE = "picasso-cache";

private static OkHttpClient.Builder defaultOkHttpClientBuilder() {
OkHttpClient.Builder builder = new OkHttpClient.Builder();
builder.connectTimeout(DEFAULT_CONNECT_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS);
builder.readTimeout(DEFAULT_READ_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS);
builder.writeTimeout(DEFAULT_WRITE_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS);
return builder;
}

private static File createDefaultCacheDir(Context context) {
File cache = new File(context.getApplicationContext().getCacheDir(), PICASSO_CACHE);
if (!cache.exists()) {
//noinspection ResultOfMethodCallIgnored
cache.mkdirs();
}
return cache;
}

private final OkHttpClient client;
private final OkHttpClient.Builder builder;

public MyOkhttpDownLoader(final Context context) {
this(createDefaultCacheDir(context));
}

public MyOkhttpDownLoader(OkHttpClient.Builder builder){
this.builder = builder;
this.client = this.builder.build();
}

@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
static long calculateDiskCacheSize(File dir) {
long size = MIN_DISK_CACHE_SIZE;

try {
StatFs statFs = new StatFs(dir.getAbsolutePath());
long available = 0l;
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2){
available = statFs.getBlockCountLong() * statFs.getBlockSizeLong();
}else{
available = ((long)statFs.getBlockCount()) * statFs.getBlockSize();
}
// Target 2% of the total space.
size = available / 50;
} catch (IllegalArgumentException ignored) {
}

// Bound inside min/max size for disk cache.
return Math.max(Math.min(size, MAX_DISK_CACHE_SIZE), MIN_DISK_CACHE_SIZE);
}

public MyOkhttpDownLoader(final File cacheDir){
this(cacheDir,calculateDiskCacheSize(cacheDir));
}

protected final OkHttpClient getClient() {
return client;
}

protected final OkHttpClient.Builder getBuilder() {
return builder;
}

public MyOkhttpDownLoader(final File cacheDir,long maxSize){
this(defaultOkHttpClientBuilder());
try {
builder.cache(new okhttp3.Cache(cacheDir, maxSize));
} catch (Exception ignored) {
}
}

public MyOkhttpDownLoader(final Context context, final long maxSize) {
this(createDefaultCacheDir(context), maxSize);
}

@Override
public Response load(Uri uri, int networkPolicy) throws IOException {
CacheControl cacheControl = null;
if (networkPolicy != 0) {
if (NetworkPolicy.isOfflineOnly(networkPolicy)) {
cacheControl = CacheControl.FORCE_CACHE;
} else {
CacheControl.Builder builder = new CacheControl.Builder();
if (!NetworkPolicy.shouldReadFromDiskCache(networkPolicy)) {
builder.noCache();
}
if (!NetworkPolicy.shouldWriteToDiskCache(networkPolicy)) {
builder.noStore();
}
cacheControl = builder.build();
}
}

okhttp3.Request.Builder builder = new okhttp3.Request.Builder().url(uri.toString());
if (cacheControl != null) {
builder.cacheControl(cacheControl);
}

okhttp3.Response response = client.newCall(builder.build()).execute();
int responseCode = response.code();
if (responseCode >= 300) {
response.body().close();
throw new ResponseException(responseCode + " " + response.message(), networkPolicy,
responseCode);
}

boolean fromCache = response.cacheResponse() != null;

ResponseBody responseBody = response.body();
return new Response(responseBody.byteStream(), fromCache, responseBody.contentLength());
}

@Override
public void shutdown() {
okhttp3.Cache cache = client.cache();
if (cache != null) {
try {
cache.close();
} catch (IOException ignored) {
}
}
}
}