Import of Volley from GitHub to AOSP. am: ec9c6e0d0e

Change-Id: Id4f28845afa5fd89dc55d0316c7760166f361afd

14 files changed, 319 insertions, 61 deletions

diff --git a/src/main/java/com/android/volley/Cache.java b/src/main/java/com/android/volley/Cache.java
index 35b2a96..b8908ac 100644
--- a/src/main/java/com/android/volley/Cache.java
+++ b/src/main/java/com/android/volley/Cache.java
@@ -16,6 +16,7 @@
 
 package com.android.volley;
 
+import androidx.annotation.Nullable;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -28,6 +29,7 @@ public interface Cache {
      * @param key Cache key
      * @return An {@link Entry} or null in the event of a cache miss
      */
+    @Nullable
     Entry get(String key);
 
     /**
diff --git a/src/main/java/com/android/volley/CacheDispatcher.java b/src/main/java/com/android/volley/CacheDispatcher.java
index be06d1f..12b1035 100644
--- a/src/main/java/com/android/volley/CacheDispatcher.java
+++ b/src/main/java/com/android/volley/CacheDispatcher.java
@@ -159,6 +159,15 @@ public class CacheDispatcher extends Thread {
                             new NetworkResponse(entry.data, entry.responseHeaders));
             request.addMarker("cache-hit-parsed");
 
+            if (!response.isSuccess()) {
+                request.addMarker("cache-parsing-failed");
+                mCache.invalidate(request.getCacheKey(), true);
+                request.setCacheEntry(null);
+                if (!mWaitingRequestManager.maybeAddToWaitingRequests(request)) {
+                    mNetworkQueue.put(request);
+                }
+                return;
+            }
             if (!entry.refreshNeeded()) {
                 // Completely unexpired cache hit. Just deliver the response.
                 mDelivery.postResponse(request, response);
diff --git a/src/main/java/com/android/volley/NetworkResponse.java b/src/main/java/com/android/volley/NetworkResponse.java
index 01f48c6..cfbc371 100644
--- a/src/main/java/com/android/volley/NetworkResponse.java
+++ b/src/main/java/com/android/volley/NetworkResponse.java
@@ -16,6 +16,7 @@
 
 package com.android.volley;
 
+import androidx.annotation.Nullable;
 import java.net.HttpURLConnection;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -42,7 +43,7 @@ public class NetworkResponse {
     public NetworkResponse(
             int statusCode,
             byte[] data,
-            Map<String, String> headers,
+            @Nullable Map<String, String> headers,
             boolean notModified,
             long networkTimeMs) {
         this(statusCode, data, headers, toAllHeaderList(headers), notModified, networkTimeMs);
@@ -62,7 +63,7 @@ public class NetworkResponse {
             byte[] data,
             boolean notModified,
             long networkTimeMs,
-            List<Header> allHeaders) {
+            @Nullable List<Header> allHeaders) {
         this(statusCode, data, toHeaderMap(allHeaders), allHeaders, notModified, networkTimeMs);
     }
 
@@ -79,7 +80,10 @@ public class NetworkResponse {
      */
     @Deprecated
     public NetworkResponse(
-            int statusCode, byte[] data, Map<String, String> headers, boolean notModified) {
+            int statusCode,
+            byte[] data,
+            @Nullable Map<String, String> headers,
+            boolean notModified) {
         this(statusCode, data, headers, notModified, /* networkTimeMs= */ 0);
     }
 
@@ -107,7 +111,7 @@ public class NetworkResponse {
      *     constructor may be removed in a future release of Volley.
      */
     @Deprecated
-    public NetworkResponse(byte[] data, Map<String, String> headers) {
+    public NetworkResponse(byte[] data, @Nullable Map<String, String> headers) {
         this(
                 HttpURLConnection.HTTP_OK,
                 data,
@@ -119,8 +123,8 @@ public class NetworkResponse {
     private NetworkResponse(
             int statusCode,
             byte[] data,
-            Map<String, String> headers,
-            List<Header> allHeaders,
+            @Nullable Map<String, String> headers,
+            @Nullable List<Header> allHeaders,
             boolean notModified,
             long networkTimeMs) {
         this.statusCode = statusCode;
@@ -150,10 +154,10 @@ public class NetworkResponse {
      * map will only contain the last one. Use {@link #allHeaders} to inspect all headers returned
      * by the server.
      */
-    public final Map<String, String> headers;
+    @Nullable public final Map<String, String> headers;
 
     /** All response headers. Must not be mutated directly. */
-    public final List<Header> allHeaders;
+    @Nullable public final List<Header> allHeaders;
 
     /** True if the server returned a 304 (Not Modified). */
     public final boolean notModified;
@@ -161,7 +165,8 @@ public class NetworkResponse {
     /** Network roundtrip time in milliseconds. */
     public final long networkTimeMs;
 
-    private static Map<String, String> toHeaderMap(List<Header> allHeaders) {
+    @Nullable
+    private static Map<String, String> toHeaderMap(@Nullable List<Header> allHeaders) {
         if (allHeaders == null) {
             return null;
         }
@@ -176,7 +181,8 @@ public class NetworkResponse {
         return headers;
     }
 
-    private static List<Header> toAllHeaderList(Map<String, String> headers) {
+    @Nullable
+    private static List<Header> toAllHeaderList(@Nullable Map<String, String> headers) {
         if (headers == null) {
             return null;
         }
diff --git a/src/main/java/com/android/volley/Request.java b/src/main/java/com/android/volley/Request.java
index 104b046..2b53f96 100644
--- a/src/main/java/com/android/volley/Request.java
+++ b/src/main/java/com/android/volley/Request.java
@@ -115,7 +115,7 @@ public abstract class Request<T> implements Comparable<Request<T>> {
      * entry will be stored here so that in the event of a "Not Modified" response, we can be sure
      * it hasn't been evicted from cache.
      */
-    private Cache.Entry mCacheEntry = null;
+    @Nullable private Cache.Entry mCacheEntry = null;
 
     /** An opaque token tagging this request; used for bulk cancellation. */
     private Object mTag;
@@ -319,6 +319,7 @@ public abstract class Request<T> implements Comparable<Request<T>> {
     }
 
     /** Returns the annotated cache entry, or null if there isn't one. */
+    @Nullable
     public Cache.Entry getCacheEntry() {
         return mCacheEntry;
     }
@@ -374,6 +375,7 @@ public abstract class Request<T> implements Comparable<Request<T>> {
      * @deprecated Use {@link #getParams()} instead.
      */
     @Deprecated
+    @Nullable
     protected Map<String, String> getPostParams() throws AuthFailureError {
         return getParams();
     }
@@ -431,6 +433,7 @@ public abstract class Request<T> implements Comparable<Request<T>> {
      *
      * @throws AuthFailureError in the event of auth failure
      */
+    @Nullable
     protected Map<String, String> getParams() throws AuthFailureError {
         return null;
     }
diff --git a/src/main/java/com/android/volley/Response.java b/src/main/java/com/android/volley/Response.java
index 2f50e2d..622bdc4 100644
--- a/src/main/java/com/android/volley/Response.java
+++ b/src/main/java/com/android/volley/Response.java
@@ -16,6 +16,8 @@
 
 package com.android.volley;
 
+import androidx.annotation.Nullable;
+
 /**
  * Encapsulates a parsed response for delivery.
  *
@@ -39,7 +41,7 @@ public class Response<T> {
     }
 
     /** Returns a successful response containing the parsed result. */
-    public static <T> Response<T> success(T result, Cache.Entry cacheEntry) {
+    public static <T> Response<T> success(@Nullable T result, @Nullable Cache.Entry cacheEntry) {
         return new Response<>(result, cacheEntry);
     }
 
@@ -51,14 +53,14 @@ public class Response<T> {
         return new Response<>(error);
     }
 
-    /** Parsed response, or null in the case of error. */
-    public final T result;
+    /** Parsed response, can be null; always null in the case of error. */
+    @Nullable public final T result;
 
-    /** Cache metadata for this response, or null in the case of error. */
-    public final Cache.Entry cacheEntry;
+    /** Cache metadata for this response; null if not cached or in the case of error. */
+    @Nullable public final Cache.Entry cacheEntry;
 
     /** Detailed error information if <code>errorCode != OK</code>. */
-    public final VolleyError error;
+    @Nullable public final VolleyError error;
 
     /** True if this response was a soft-expired one and a second one MAY be coming. */
     public boolean intermediate = false;
@@ -68,7 +70,7 @@ public class Response<T> {
         return error == null;
     }
 
-    private Response(T result, Cache.Entry cacheEntry) {
+    private Response(@Nullable T result, @Nullable Cache.Entry cacheEntry) {
         this.result = result;
         this.cacheEntry = cacheEntry;
         this.error = null;
diff --git a/src/main/java/com/android/volley/toolbox/DiskBasedCache.java b/src/main/java/com/android/volley/toolbox/DiskBasedCache.java
index a6a0c83..d4310e0 100644
--- a/src/main/java/com/android/volley/toolbox/DiskBasedCache.java
+++ b/src/main/java/com/android/volley/toolbox/DiskBasedCache.java
@@ -55,8 +55,8 @@ public class DiskBasedCache implements Cache {
     /** Total amount of space currently used by the cache in bytes. */
     private long mTotalSize = 0;
 
-    /** The root directory to use for the cache. */
-    private final File mRootDirectory;
+    /** The supplier for the root directory to use for the cache. */
+    private final FileSupplier mRootDirectorySupplier;
 
     /** The maximum size of the cache in bytes. */
     private final int mMaxCacheSizeInBytes;
@@ -78,8 +78,27 @@ public class DiskBasedCache implements Cache {
      *     briefly exceed this size on disk when writing a new entry that pushes it over the limit
      *     until the ensuing pruning completes.
      */
-    public DiskBasedCache(File rootDirectory, int maxCacheSizeInBytes) {
-        mRootDirectory = rootDirectory;
+    public DiskBasedCache(final File rootDirectory, int maxCacheSizeInBytes) {
+        mRootDirectorySupplier =
+                new FileSupplier() {
+                    @Override
+                    public File get() {
+                        return rootDirectory;
+                    }
+                };
+        mMaxCacheSizeInBytes = maxCacheSizeInBytes;
+    }
+
+    /**
+     * Constructs an instance of the DiskBasedCache at the specified directory.
+     *
+     * @param rootDirectorySupplier The supplier for the root directory of the cache.
+     * @param maxCacheSizeInBytes The maximum size of the cache in bytes. Note that the cache may
+     *     briefly exceed this size on disk when writing a new entry that pushes it over the limit
+     *     until the ensuing pruning completes.
+     */
+    public DiskBasedCache(FileSupplier rootDirectorySupplier, int maxCacheSizeInBytes) {
+        mRootDirectorySupplier = rootDirectorySupplier;
         mMaxCacheSizeInBytes = maxCacheSizeInBytes;
     }
 
@@ -93,10 +112,20 @@ public class DiskBasedCache implements Cache {
         this(rootDirectory, DEFAULT_DISK_USAGE_BYTES);
     }
 
+    /**
+     * Constructs an instance of the DiskBasedCache at the specified directory using the default
+     * maximum cache size of 5MB.
+     *
+     * @param rootDirectorySupplier The supplier for the root directory of the cache.
+     */
+    public DiskBasedCache(FileSupplier rootDirectorySupplier) {
+        this(rootDirectorySupplier, DEFAULT_DISK_USAGE_BYTES);
+    }
+
     /** Clears the cache. Deletes all cached files from disk. */
     @Override
     public synchronized void clear() {
-        File[] files = mRootDirectory.listFiles();
+        File[] files = mRootDirectorySupplier.get().listFiles();
         if (files != null) {
             for (File file : files) {
                 file.delete();
@@ -150,13 +179,14 @@ public class DiskBasedCache implements Cache {
      */
     @Override
     public synchronized void initialize() {
-        if (!mRootDirectory.exists()) {
-            if (!mRootDirectory.mkdirs()) {
-                VolleyLog.e("Unable to create cache dir %s", mRootDirectory.getAbsolutePath());
+        File rootDirectory = mRootDirectorySupplier.get();
+        if (!rootDirectory.exists()) {
+            if (!rootDirectory.mkdirs()) {
+                VolleyLog.e("Unable to create cache dir %s", rootDirectory.getAbsolutePath());
             }
             return;
         }
-        File[] files = mRootDirectory.listFiles();
+        File[] files = rootDirectory.listFiles();
         if (files == null) {
             return;
         }
@@ -226,12 +256,12 @@ public class DiskBasedCache implements Cache {
             e.size = file.length();
             putEntry(key, e);
             pruneIfNeeded();
-            return;
         } catch (IOException e) {
-        }
-        boolean deleted = file.delete();
-        if (!deleted) {
-            VolleyLog.d("Could not clean up file %s", file.getAbsolutePath());
+            boolean deleted = file.delete();
+            if (!deleted) {
+                VolleyLog.d("Could not clean up file %s", file.getAbsolutePath());
+            }
+            initializeIfRootDirectoryDeleted();
         }
     }
 
@@ -262,7 +292,22 @@ public class DiskBasedCache implements Cache {
 
     /** Returns a file object for the given cache key. */
     public File getFileForKey(String key) {
-        return new File(mRootDirectory, getFilenameForKey(key));
+        return new File(mRootDirectorySupplier.get(), getFilenameForKey(key));
+    }
+
+    /** Re-initialize the cache if the directory was deleted. */
+    private void initializeIfRootDirectoryDeleted() {
+        if (!mRootDirectorySupplier.get().exists()) {
+            VolleyLog.d("Re-initializing cache after external clearing.");
+            mEntries.clear();
+            mTotalSize = 0;
+            initialize();
+        }
+    }
+
+    /** Represents a supplier for {@link File}s. */
+    public interface FileSupplier {
+        File get();
     }
 
     /** Prunes the cache to fit the maximum size. */
diff --git a/src/main/java/com/android/volley/toolbox/HttpHeaderParser.java b/src/main/java/com/android/volley/toolbox/HttpHeaderParser.java
index 27d1268..1b410af 100644
--- a/src/main/java/com/android/volley/toolbox/HttpHeaderParser.java
+++ b/src/main/java/com/android/volley/toolbox/HttpHeaderParser.java
@@ -16,6 +16,7 @@
 
 package com.android.volley.toolbox;
 
+import androidx.annotation.Nullable;
 import com.android.volley.Cache;
 import com.android.volley.Header;
 import com.android.volley.NetworkResponse;
@@ -37,7 +38,11 @@ public class HttpHeaderParser {
 
     private static final String DEFAULT_CONTENT_CHARSET = "ISO-8859-1";
 
-    private static final String RFC1123_FORMAT = "EEE, dd MMM yyyy HH:mm:ss zzz";
+    private static final String RFC1123_PARSE_FORMAT = "EEE, dd MMM yyyy HH:mm:ss zzz";
+
+    // Hardcode 'GMT' rather than using 'zzz' since some platforms append an extraneous +00:00.
+    // See #287.
+    private static final String RFC1123_OUTPUT_FORMAT = "EEE, dd MMM yyyy HH:mm:ss 'GMT'";
 
     /**
      * Extracts a {@link com.android.volley.Cache.Entry} from a {@link NetworkResponse}.
@@ -45,10 +50,14 @@ public class HttpHeaderParser {
      * @param response The network response to parse headers from
      * @return a cache entry for the given response, or null if the response is not cacheable.
      */
+    @Nullable
     public static Cache.Entry parseCacheHeaders(NetworkResponse response) {
         long now = System.currentTimeMillis();
 
         Map<String, String> headers = response.headers;
+        if (headers == null) {
+            return null;
+        }
 
         long serverDate = 0;
         long lastModified = 0;
@@ -132,21 +141,29 @@ public class HttpHeaderParser {
     public static long parseDateAsEpoch(String dateStr) {
         try {
             // Parse date in RFC1123 format if this header contains one
-            return newRfc1123Formatter().parse(dateStr).getTime();
+            return newUsGmtFormatter(RFC1123_PARSE_FORMAT).parse(dateStr).getTime();
         } catch (ParseException e) {
             // Date in invalid format, fallback to 0
-            VolleyLog.e(e, "Unable to parse dateStr: %s, falling back to 0", dateStr);
+            // If the value is either "0" or "-1" we only log to verbose,
+            // these values are pretty common and cause log spam.
+            String message = "Unable to parse dateStr: %s, falling back to 0";
+            if ("0".equals(dateStr) || "-1".equals(dateStr)) {
+                VolleyLog.v(message, dateStr);
+            } else {
+                VolleyLog.e(e, message, dateStr);
+            }
+
             return 0;
         }
     }
 
     /** Format an epoch date in RFC1123 format. */
     static String formatEpochAsRfc1123(long epoch) {
-        return newRfc1123Formatter().format(new Date(epoch));
+        return newUsGmtFormatter(RFC1123_OUTPUT_FORMAT).format(new Date(epoch));
     }
 
-    private static SimpleDateFormat newRfc1123Formatter() {
-        SimpleDateFormat formatter = new SimpleDateFormat(RFC1123_FORMAT, Locale.US);
+    private static SimpleDateFormat newUsGmtFormatter(String format) {
+        SimpleDateFormat formatter = new SimpleDateFormat(format, Locale.US);
         formatter.setTimeZone(TimeZone.getTimeZone("GMT"));
         return formatter;
     }
@@ -159,7 +176,11 @@ public class HttpHeaderParser {
      * @return Returns the charset specified in the Content-Type of this header, or the
      *     defaultCharset if none can be found.
      */
-    public static String parseCharset(Map<String, String> headers, String defaultCharset) {
+    public static String parseCharset(
+            @Nullable Map<String, String> headers, String defaultCharset) {
+        if (headers == null) {
+            return defaultCharset;
+        }
         String contentType = headers.get(HEADER_CONTENT_TYPE);
         if (contentType != null) {
             String[] params = contentType.split(";", 0);
@@ -180,7 +201,7 @@ public class HttpHeaderParser {
      * Returns the charset specified in the Content-Type of this header, or the HTTP default
      * (ISO-8859-1) if none can be found.
      */
-    public static String parseCharset(Map<String, String> headers) {
+    public static String parseCharset(@Nullable Map<String, String> headers) {
         return parseCharset(headers, DEFAULT_CONTENT_CHARSET);
     }
 
diff --git a/src/main/java/com/android/volley/toolbox/HurlStack.java b/src/main/java/com/android/volley/toolbox/HurlStack.java
index f85d42c..9c38023 100644
--- a/src/main/java/com/android/volley/toolbox/HurlStack.java
+++ b/src/main/java/com/android/volley/toolbox/HurlStack.java
@@ -25,6 +25,7 @@ import java.io.DataOutputStream;
 import java.io.FilterInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.util.ArrayList;
@@ -111,7 +112,7 @@ public class HurlStack extends BaseHttpStack {
                     responseCode,
                     convertHeaders(connection.getHeaderFields()),
                     connection.getContentLength(),
-                    new UrlConnectionInputStream(connection));
+                    createInputStream(request, connection));
         } finally {
             if (!keepConnectionOpen) {
                 connection.disconnect();
@@ -169,6 +170,19 @@ public class HurlStack extends BaseHttpStack {
     }
 
     /**
+     * Create and return an InputStream from which the response will be read.
+     *
+     * <p>May be overridden by subclasses to manipulate or monitor this input stream.
+     *
+     * @param request current request.
+     * @param connection current connection of request.
+     * @return an InputStream from which the response will be read.
+     */
+    protected InputStream createInputStream(Request<?> request, HttpURLConnection connection) {
+        return new UrlConnectionInputStream(connection);
+    }
+
+    /**
      * Initializes an {@link InputStream} from the given {@link HttpURLConnection}.
      *
      * @param connection
@@ -223,7 +237,7 @@ public class HurlStack extends BaseHttpStack {
     // NOTE: Any request headers added here (via setRequestProperty or addRequestProperty) should be
     // checked against the existing properties in the connection and not overridden if already set.
     @SuppressWarnings("deprecation")
-    /* package */ static void setConnectionParametersForRequest(
+    /* package */ void setConnectionParametersForRequest(
             HttpURLConnection connection, Request<?> request) throws IOException, AuthFailureError {
         switch (request.getMethod()) {
             case Method.DEPRECATED_GET_OR_POST:
@@ -270,7 +284,7 @@ public class HurlStack extends BaseHttpStack {
         }
     }
 
-    private static void addBodyIfExists(HttpURLConnection connection, Request<?> request)
+    private void addBodyIfExists(HttpURLConnection connection, Request<?> request)
             throws IOException, AuthFailureError {
         byte[] body = request.getBody();
         if (body != null) {
@@ -278,7 +292,7 @@ public class HurlStack extends BaseHttpStack {
         }
     }
 
-    private static void addBody(HttpURLConnection connection, Request<?> request, byte[] body)
+    private void addBody(HttpURLConnection connection, Request<?> request, byte[] body)
             throws IOException {
         // Prepare output. There is no need to set Content-Length explicitly,
         // since this is handled by HttpURLConnection using the size of the prepared
@@ -289,8 +303,25 @@ public class HurlStack extends BaseHttpStack {
             connection.setRequestProperty(
                     HttpHeaderParser.HEADER_CONTENT_TYPE, request.getBodyContentType());
         }
-        DataOutputStream out = new DataOutputStream(connection.getOutputStream());
+        DataOutputStream out =
+                new DataOutputStream(createOutputStream(request, connection, body.length));
         out.write(body);
         out.close();
     }
+
+    /**
+     * Create and return an OutputStream to which the request body will be written.
+     *
+     * <p>May be overridden by subclasses to manipulate or monitor this output stream.
+     *
+     * @param request current request.
+     * @param connection current connection of request.
+     * @param length size of stream to write.
+     * @return an OutputStream to which the request body will be written.
+     * @throws IOException if an I/O error occurs while creating the stream.
+     */
+    protected OutputStream createOutputStream(
+            Request<?> request, HttpURLConnection connection, int length) throws IOException {
+        return connection.getOutputStream();
+    }
 }
diff --git a/src/main/java/com/android/volley/toolbox/ImageLoader.java b/src/main/java/com/android/volley/toolbox/ImageLoader.java
index b80072b..eece2cf 100644
--- a/src/main/java/com/android/volley/toolbox/ImageLoader.java
+++ b/src/main/java/com/android/volley/toolbox/ImageLoader.java
@@ -20,6 +20,7 @@ import android.os.Looper;
 import android.widget.ImageView;
 import android.widget.ImageView.ScaleType;
 import androidx.annotation.MainThread;
+import androidx.annotation.Nullable;
 import com.android.volley.Request;
 import com.android.volley.RequestQueue;
 import com.android.volley.Response.ErrorListener;
@@ -70,6 +71,7 @@ public class ImageLoader {
      * LruCache is recommended.
      */
     public interface ImageCache {
+        @Nullable
         Bitmap getBitmap(String url);
 
         void putBitmap(String url, Bitmap bitmap);
diff --git a/src/main/java/com/android/volley/toolbox/Volley.java b/src/main/java/com/android/volley/toolbox/Volley.java
index 1982802..bc65c9c 100644
--- a/src/main/java/com/android/volley/toolbox/Volley.java
+++ b/src/main/java/com/android/volley/toolbox/Volley.java
@@ -86,8 +86,22 @@ public class Volley {
     }
 
     private static RequestQueue newRequestQueue(Context context, Network network) {
-        File cacheDir = new File(context.getCacheDir(), DEFAULT_CACHE_DIR);
-        RequestQueue queue = new RequestQueue(new DiskBasedCache(cacheDir), network);
+        final Context appContext = context.getApplicationContext();
+        // Use a lazy supplier for the cache directory so that newRequestQueue() can be called on
+        // main thread without causing strict mode violation.
+        DiskBasedCache.FileSupplier cacheSupplier =
+                new DiskBasedCache.FileSupplier() {
+                    private File cacheDir = null;
+
+                    @Override
+                    public File get() {
+                        if (cacheDir == null) {
+                            cacheDir = new File(appContext.getCacheDir(), DEFAULT_CACHE_DIR);
+                        }
+                        return cacheDir;
+                    }
+                };
+        RequestQueue queue = new RequestQueue(new DiskBasedCache(cacheSupplier), network);
         queue.start();
         return queue;
     }
diff --git a/src/test/java/com/android/volley/CacheDispatcherTest.java b/src/test/java/com/android/volley/CacheDispatcherTest.java
index 2592a0b..aef6785 100644
--- a/src/test/java/com/android/volley/CacheDispatcherTest.java
+++ b/src/test/java/com/android/volley/CacheDispatcherTest.java
@@ -140,6 +140,25 @@ public class CacheDispatcherTest {
         assertSame(entry, mRequest.getCacheEntry());
     }
 
+    // An fresh cache hit with parse error, does not post a response and queues to the network.
+    @Test
+    public void freshCacheHit_parseError() throws Exception {
+        Request request = mock(Request.class);
+        when(request.parseNetworkResponse(any(NetworkResponse.class)))
+                .thenReturn(Response.error(new ParseError()));
+        when(request.getCacheKey()).thenReturn("cache/key");
+        Cache.Entry entry = CacheTestUtils.makeRandomCacheEntry(null, false, false);
+        when(mCache.get(anyString())).thenReturn(entry);
+
+        mDispatcher.processRequest(request);
+
+        verifyNoResponse(mDelivery);
+        verify(mNetworkQueue).put(request);
+        assertNull(request.getCacheEntry());
+        verify(mCache).invalidate("cache/key", true);
+        verify(request).addMarker("cache-parsing-failed");
+    }
+
     @Test
     public void duplicateCacheMiss() throws Exception {
         StringRequest secondRequest =
diff --git a/src/test/java/com/android/volley/toolbox/DiskBasedCacheTest.java b/src/test/java/com/android/volley/toolbox/DiskBasedCacheTest.java
index e499a37..ccf68fa 100644
--- a/src/test/java/com/android/volley/toolbox/DiskBasedCacheTest.java
+++ b/src/test/java/com/android/volley/toolbox/DiskBasedCacheTest.java
@@ -587,11 +587,28 @@ public class DiskBasedCacheTest {
     public void publicMethods() throws Exception {
         // Catch-all test to find API-breaking changes.
         assertNotNull(DiskBasedCache.class.getConstructor(File.class, int.class));
+        assertNotNull(
+                DiskBasedCache.class.getConstructor(DiskBasedCache.FileSupplier.class, int.class));
         assertNotNull(DiskBasedCache.class.getConstructor(File.class));
+        assertNotNull(DiskBasedCache.class.getConstructor(DiskBasedCache.FileSupplier.class));
 
         assertNotNull(DiskBasedCache.class.getMethod("getFileForKey", String.class));
     }
 
+    @Test
+    public void initializeIfRootDirectoryDeleted() {
+        temporaryFolder.delete();
+
+        Cache.Entry entry = randomData(101);
+        cache.put("key1", entry);
+
+        assertThat(cache.get("key1"), is(nullValue()));
+
+        // confirm that we can now store entries
+        cache.put("key2", entry);
+        assertThatEntriesAreEqual(cache.get("key2"), entry);
+    }
+
     /* Test helpers */
 
     private void assertThatEntriesAreEqual(Cache.Entry actual, Cache.Entry expected) {
diff --git a/src/test/java/com/android/volley/toolbox/HttpHeaderParserTest.java b/src/test/java/com/android/volley/toolbox/HttpHeaderParserTest.java
index 9b670f9..7780c3e 100644
--- a/src/test/java/com/android/volley/toolbox/HttpHeaderParserTest.java
+++ b/src/test/java/com/android/volley/toolbox/HttpHeaderParserTest.java
@@ -67,6 +67,12 @@ public class HttpHeaderParserTest {
     }
 
     @Test
+    public void parseCacheHeaders_nullHeaders() {
+        response = new NetworkResponse(0, null, null, false);
+        assertNull(HttpHeaderParser.parseCacheHeaders(response));
+    }
+
+    @Test
     public void parseCacheHeaders_headersSet() {
         headers.put("MyCustomHeader", "42");
 
@@ -282,6 +288,9 @@ public class HttpHeaderParserTest {
         // None specified, extra semicolon
         headers.put("Content-Type", "text/plain;");
         assertEquals("ISO-8859-1", HttpHeaderParser.parseCharset(headers));
+
+        // No headers, use default charset
+        assertEquals("utf-8", HttpHeaderParser.parseCharset(null, "utf-8"));
     }
 
     @Test
diff --git a/src/test/java/com/android/volley/toolbox/HurlStackTest.java b/src/test/java/com/android/volley/toolbox/HurlStackTest.java
index c1fc92d..7508244 100644
--- a/src/test/java/com/android/volley/toolbox/HurlStackTest.java
+++ b/src/test/java/com/android/volley/toolbox/HurlStackTest.java
@@ -17,6 +17,7 @@
 package com.android.volley.toolbox;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.never;
@@ -24,11 +25,16 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import com.android.volley.Header;
+import com.android.volley.Request;
 import com.android.volley.Request.Method;
 import com.android.volley.mock.TestRequest;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
+import java.io.FilterInputStream;
+import java.io.FilterOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
 import java.net.HttpURLConnection;
 import java.net.SocketTimeoutException;
 import java.net.URL;
@@ -62,6 +68,26 @@ public class HurlStackTest {
                     protected HttpURLConnection createConnection(URL url) {
                         return mMockConnection;
                     }
+
+                    @Override
+                    protected InputStream createInputStream(
+                            Request<?> request, HttpURLConnection connection) {
+                        return new MonitoringInputStream(
+                                super.createInputStream(request, connection));
+                    }
+
+                    @Override
+                    protected OutputStream createOutputStream(
+                            Request<?> request, HttpURLConnection connection, int length)
+                            throws IOException {
+                        if (request instanceof MonitoredRequest) {
+                            return new MonitoringOutputStream(
+                                    super.createOutputStream(request, connection, length),
+                                    (MonitoredRequest) request,
+                                    length);
+                        }
+                        return super.createOutputStream(request, connection, length);
+                    }
                 };
     }
 
@@ -70,7 +96,7 @@ public class HurlStackTest {
         TestRequest.DeprecatedGet request = new TestRequest.DeprecatedGet();
         assertEquals(request.getMethod(), Method.DEPRECATED_GET_OR_POST);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection, never()).setRequestMethod(anyString());
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -80,7 +106,7 @@ public class HurlStackTest {
         TestRequest.DeprecatedPost request = new TestRequest.DeprecatedPost();
         assertEquals(request.getMethod(), Method.DEPRECATED_GET_OR_POST);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("POST");
         verify(mMockConnection).setDoOutput(true);
     }
@@ -90,7 +116,7 @@ public class HurlStackTest {
         TestRequest.Get request = new TestRequest.Get();
         assertEquals(request.getMethod(), Method.GET);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("GET");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -100,7 +126,7 @@ public class HurlStackTest {
         TestRequest.Post request = new TestRequest.Post();
         assertEquals(request.getMethod(), Method.POST);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("POST");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -110,7 +136,7 @@ public class HurlStackTest {
         TestRequest.PostWithBody request = new TestRequest.PostWithBody();
         assertEquals(request.getMethod(), Method.POST);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("POST");
         verify(mMockConnection).setDoOutput(true);
     }
@@ -120,7 +146,7 @@ public class HurlStackTest {
         TestRequest.Put request = new TestRequest.Put();
         assertEquals(request.getMethod(), Method.PUT);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("PUT");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -130,7 +156,7 @@ public class HurlStackTest {
         TestRequest.PutWithBody request = new TestRequest.PutWithBody();
         assertEquals(request.getMethod(), Method.PUT);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("PUT");
         verify(mMockConnection).setDoOutput(true);
     }
@@ -140,7 +166,7 @@ public class HurlStackTest {
         TestRequest.Delete request = new TestRequest.Delete();
         assertEquals(request.getMethod(), Method.DELETE);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("DELETE");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -150,7 +176,7 @@ public class HurlStackTest {
         TestRequest.Head request = new TestRequest.Head();
         assertEquals(request.getMethod(), Method.HEAD);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("HEAD");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -160,7 +186,7 @@ public class HurlStackTest {
         TestRequest.Options request = new TestRequest.Options();
         assertEquals(request.getMethod(), Method.OPTIONS);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("OPTIONS");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -170,7 +196,7 @@ public class HurlStackTest {
         TestRequest.Trace request = new TestRequest.Trace();
         assertEquals(request.getMethod(), Method.TRACE);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("TRACE");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -180,7 +206,7 @@ public class HurlStackTest {
         TestRequest.Patch request = new TestRequest.Patch();
         assertEquals(request.getMethod(), Method.PATCH);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("PATCH");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -190,7 +216,7 @@ public class HurlStackTest {
         TestRequest.PatchWithBody request = new TestRequest.PatchWithBody();
         assertEquals(request.getMethod(), Method.PATCH);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("PATCH");
         verify(mMockConnection).setDoOutput(true);
     }
@@ -256,4 +282,56 @@ public class HurlStackTest {
         expected.add(new Header("HeaderB", "ValueB_2"));
         assertEquals(expected, result);
     }
+
+    @Test
+    public void interceptResponseStream() throws Exception {
+        when(mMockConnection.getResponseCode()).thenReturn(HttpURLConnection.HTTP_OK);
+        when(mMockConnection.getInputStream())
+                .thenReturn(new ByteArrayInputStream("hello".getBytes(StandardCharsets.UTF_8)));
+        HttpResponse response =
+                mHurlStack.executeRequest(
+                        new TestRequest.Get(), Collections.<String, String>emptyMap());
+        assertTrue(response.getContent() instanceof MonitoringInputStream);
+    }
+
+    @Test
+    public void interceptRequestStream() throws Exception {
+        MonitoredRequest request = new MonitoredRequest();
+        mHurlStack.executeRequest(request, Collections.<String, String>emptyMap());
+        assertTrue(request.totalRequestBytes > 0);
+        assertEquals(request.totalRequestBytes, request.requestBytesRead);
+    }
+
+    private static class MonitoringInputStream extends FilterInputStream {
+        private MonitoringInputStream(InputStream in) {
+            super(in);
+        }
+    }
+
+    private static class MonitoringOutputStream extends FilterOutputStream {
+        private MonitoredRequest request;
+
+        private MonitoringOutputStream(OutputStream out, MonitoredRequest request, int length) {
+            super(out);
+            this.request = request;
+            this.request.totalRequestBytes = length;
+        }
+
+        @Override
+        public void write(int b) throws IOException {
+            this.request.requestBytesRead++;
+            out.write(b);
+        }
+
+        @Override
+        public void write(byte[] b, int off, int len) throws IOException {
+            this.request.requestBytesRead += len;
+            out.write(b, off, len);
+        }
+    }
+
+    private static class MonitoredRequest extends TestRequest.PostWithBody {
+        int requestBytesRead = 0;
+        int totalRequestBytes = 0;
+    }
 }