https://source.android.com/ 
/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.webkit;

import android.annotation.Nullable;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Map;


Manages the HTTP cache used by an application's WebView instances. 
Deprecated:Access to the HTTP cache will be removed in a future release.
@hideSince VERSION_CODES.JELLY_BEAN_MR1
/**
 * Manages the HTTP cache used by an application's {@link WebView} instances.
 * @deprecated Access to the HTTP cache will be removed in a future release.
 * @hide Since {@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR1}
 */
// The class CacheManager provides the persistent cache of content that is
// received over the network. The component handles parsing of HTTP headers and
// utilizes the relevant cache headers to determine if the content should be
// stored and if so, how long it is valid for. Network requests are provided to
// this component and if they can not be resolved by the cache, the HTTP headers
// are attached, as appropriate, to the request for revalidation of content. The
// class also manages the cache size.
//
// CacheManager may only be used if your activity contains a WebView.
@Deprecated
public final class CacheManager {
    
Represents a resource stored in the HTTP cache. Instances of this class can be obtained by calling CacheManager.getCacheFile(String, Map)). 
Deprecated:Access to the HTTP cache will be removed in a future release.
/**
     * Represents a resource stored in the HTTP cache. Instances of this class
     * can be obtained by calling
     * {@link CacheManager#getCacheFile CacheManager.getCacheFile(String, Map<String, String>))}.
     *
     * @deprecated Access to the HTTP cache will be removed in a future release.
     */
    @Deprecated
    public static class CacheResult {
        // these fields are saved to the database
        int httpStatusCode;
        long contentLength;
        long expires;
        String expiresString;
        String localPath;
        String lastModified;
        String etag;
        String mimeType;
        String location;
        String encoding;
        String contentdisposition;
        String crossDomain;

        // these fields are NOT saved to the database
        InputStream inStream;
        OutputStream outStream;
        File outFile;

        
Gets the status code of this cache entry.

Returns:the status code of this cache entry
/**
         * Gets the status code of this cache entry.
         *
         * @return the status code of this cache entry
         */
        public int getHttpStatusCode() {
            return httpStatusCode;
        }

        
Gets the content length of this cache entry.

Returns:the content length of this cache entry
/**
         * Gets the content length of this cache entry.
         *
         * @return the content length of this cache entry
         */
        public long getContentLength() {
            return contentLength;
        }

        
Gets the path of the file used to store the content of this cache entry, relative to the base directory of the cache. See CacheManager.getCacheFileBaseDir(). 
Returns:the path of the file used to store this cache entry
/**
         * Gets the path of the file used to store the content of this cache
         * entry, relative to the base directory of the cache. See
         * {@link CacheManager#getCacheFileBaseDir CacheManager.getCacheFileBaseDir()}.
         *
         * @return the path of the file used to store this cache entry
         */
        public String getLocalPath() {
            return localPath;
        }

        
Gets the expiry date of this cache entry, expressed in milliseconds
since midnight, January 1, 1970 UTC.

Returns:the expiry date of this cache entry
/**
         * Gets the expiry date of this cache entry, expressed in milliseconds
         * since midnight, January 1, 1970 UTC.
         *
         * @return the expiry date of this cache entry
         */
        public long getExpires() {
            return expires;
        }

        
Gets the expiry date of this cache entry, expressed as a string.

Returns:the expiry date of this cache entry
/**
         * Gets the expiry date of this cache entry, expressed as a string.
         *
         * @return the expiry date of this cache entry
         *
         */
        public String getExpiresString() {
            return expiresString;
        }

        
Gets the date at which this cache entry was last modified, expressed
as a string.

Returns:the date at which this cache entry was last modified
/**
         * Gets the date at which this cache entry was last modified, expressed
         * as a string.
         *
         * @return the date at which this cache entry was last modified
         */
        public String getLastModified() {
            return lastModified;
        }

        
Gets the entity tag of this cache entry.

Returns:the entity tag of this cache entry
/**
         * Gets the entity tag of this cache entry.
         *
         * @return the entity tag of this cache entry
         */
        public String getETag() {
            return etag;
        }

        
Gets the MIME type of this cache entry.

Returns:the MIME type of this cache entry
/**
         * Gets the MIME type of this cache entry.
         *
         * @return the MIME type of this cache entry
         */
        public String getMimeType() {
            return mimeType;
        }

        
Gets the value of the HTTP 'Location' header with which this cache
entry was received.

Returns:the HTTP 'Location' header for this cache entry
/**
         * Gets the value of the HTTP 'Location' header with which this cache
         * entry was received.
         *
         * @return the HTTP 'Location' header for this cache entry
         */
        public String getLocation() {
            return location;
        }

        
Gets the encoding of this cache entry.

Returns:the encoding of this cache entry
/**
         * Gets the encoding of this cache entry.
         *
         * @return the encoding of this cache entry
         */
        public String getEncoding() {
            return encoding;
        }

        
Gets the value of the HTTP 'Content-Disposition' header with which
this cache entry was received.

Returns:the HTTP 'Content-Disposition' header for this cache entry
/**
         * Gets the value of the HTTP 'Content-Disposition' header with which
         * this cache entry was received.
         *
         * @return the HTTP 'Content-Disposition' header for this cache entry
         *
         */
        public String getContentDisposition() {
            return contentdisposition;
        }

        
Gets the input stream to the content of this cache entry, to allow content to be read. See CacheManager.getCacheFile(String, Map). 
Returns:an input stream to the content of this cache entry
/**
         * Gets the input stream to the content of this cache entry, to allow
         * content to be read. See
         * {@link CacheManager#getCacheFile CacheManager.getCacheFile(String, Map<String, String>)}.
         *
         * @return an input stream to the content of this cache entry
         */
        public InputStream getInputStream() {
            return inStream;
        }

        
Gets an output stream to the content of this cache entry, to allow content to be written. See CacheManager.saveCacheFile(String, CacheResult). 
Returns:an output stream to the content of this cache entry
/**
         * Gets an output stream to the content of this cache entry, to allow
         * content to be written. See
         * {@link CacheManager#saveCacheFile CacheManager.saveCacheFile(String, CacheResult)}.
         *
         * @return an output stream to the content of this cache entry
         */
        // Note that this is always null for objects returned by getCacheFile()!
        public OutputStream getOutputStream() {
            return outStream;
        }


        
Sets an input stream to the content of this cache entry.

Params:
  • stream – an input stream to the content of this cache entry
/**
         * Sets an input stream to the content of this cache entry.
         *
         * @param stream an input stream to the content of this cache entry
         */
        public void setInputStream(InputStream stream) {
            this.inStream = stream;
        }

        
Sets the encoding of this cache entry.

Params:
  • encoding – the encoding of this cache entry
/**
         * Sets the encoding of this cache entry.
         *
         * @param encoding the encoding of this cache entry
         */
        public void setEncoding(String encoding) {
            this.encoding = encoding;
        }

        
@hide
/**
         * @hide
         */
        public void setContentLength(long contentLength) {
            this.contentLength = contentLength;
        }
    }

    
Gets the base directory in which the files used to store the contents of cache entries are placed. See CacheManager.CacheResult.getLocalPath(). 
Returns:the base directory of the cache
Deprecated:This method no longer has any effect and always returns null.
/**
     * Gets the base directory in which the files used to store the contents of
     * cache entries are placed. See
     * {@link CacheManager.CacheResult#getLocalPath CacheManager.CacheResult.getLocalPath()}.
     *
     * @return the base directory of the cache
     * @deprecated This method no longer has any effect and always returns {@code null}.
     */
    @Deprecated
    @Nullable
    public static File getCacheFileBaseDir() {
        return null;
    }

    
Gets whether the HTTP cache is disabled.

Returns:true if the HTTP cache is disabled
Deprecated:This method no longer has any effect and always returns false.
/**
     * Gets whether the HTTP cache is disabled.
     *
     * @return {@code true} if the HTTP cache is disabled
     * @deprecated This method no longer has any effect and always returns {@code false}.
     */
    @Deprecated
    public static boolean cacheDisabled() {
        return false;
    }

    
Starts a cache transaction. Returns true if this is the only running transaction. Otherwise, this transaction is nested inside currently running transactions and false is returned. 
Returns:true if this is the only running transaction
Deprecated:This method no longer has any effect and always returns false.
/**
     * Starts a cache transaction. Returns {@code true} if this is the only running
     * transaction. Otherwise, this transaction is nested inside currently
     * running transactions and {@code false} is returned.
     *
     * @return {@code true} if this is the only running transaction
     * @deprecated This method no longer has any effect and always returns {@code false}.
     */
    @Deprecated
    public static boolean startCacheTransaction() {
        return false;
    }

    
Ends the innermost cache transaction and returns whether this was the
only running transaction.

Returns:true if this was the only running transaction
Deprecated:This method no longer has any effect and always returns false.
/**
     * Ends the innermost cache transaction and returns whether this was the
     * only running transaction.
     *
     * @return {@code true} if this was the only running transaction
     * @deprecated This method no longer has any effect and always returns {@code false}.
     */
    @Deprecated
    public static boolean endCacheTransaction() {
        return false;
    }

    
Gets the cache entry for the specified URL, or null if none is found. If a non-null value is provided for the HTTP headers map, and the cache entry needs validation, appropriate headers will be added to the map. The input stream of the CacheEntry object should be closed by the caller when access to the underlying file is no longer required. 
Params:
  • url – the URL for which a cache entry is requested
  • headers – a map from HTTP header name to value, to be populated
               for the returned cache entry
Returns:the cache entry for the specified URL
Deprecated:This method no longer has any effect and always returns null.
/**
     * Gets the cache entry for the specified URL, or {@code null} if none is found.
     * If a non-null value is provided for the HTTP headers map, and the cache
     * entry needs validation, appropriate headers will be added to the map.
     * The input stream of the CacheEntry object should be closed by the caller
     * when access to the underlying file is no longer required.
     *
     * @param url the URL for which a cache entry is requested
     * @param headers a map from HTTP header name to value, to be populated
     *                for the returned cache entry
     * @return the cache entry for the specified URL
     * @deprecated This method no longer has any effect and always returns {@code null}.
     */
    @Deprecated
    @Nullable
    public static CacheResult getCacheFile(String url,
            Map<String, String> headers) {
        return null;
    }

    
Adds a cache entry to the HTTP cache for the specicifed URL. Also closes
the cache entry's output stream.

Params:
  • url – the URL for which the cache entry should be added
  • cacheResult – the cache entry to add
Deprecated:Access to the HTTP cache will be removed in a future release.
/**
     * Adds a cache entry to the HTTP cache for the specicifed URL. Also closes
     * the cache entry's output stream.
     *
     * @param url the URL for which the cache entry should be added
     * @param cacheResult the cache entry to add
     * @deprecated Access to the HTTP cache will be removed in a future release.
     */
    @Deprecated
    public static void saveCacheFile(String url, CacheResult cacheResult) {
        saveCacheFile(url, 0, cacheResult);
    }

    static void saveCacheFile(String url, long postIdentifier,
            CacheResult cacheRet) {
        try {
            cacheRet.outStream.close();
        } catch (IOException e) {
            return;
        }

        // This method is exposed in the public API but the API provides no
        // way to obtain a new CacheResult object with a non-null output
        // stream ...
        // - CacheResult objects returned by getCacheFile() have a null
        //   output stream.
        // - new CacheResult objects have a null output stream and no
        //   setter is provided.
        // Since this method throws a null pointer exception in this case,
        // it is effectively useless from the point of view of the public
        // API.
        //
        // With the Chromium HTTP stack we continue to throw the same
        // exception for 'backwards compatibility' with the Android HTTP
        // stack.
        //
        // This method is not used from within this package, and for public API
        // use, we should already have thrown an exception above.
        assert false;
    }
}