DownloadManager:no handler found for type application/epub+zip

若你通过DownloadManager来来download一些比如epub等这样格式的file,你会遇到no handler found for type application/epub+zip这样的error message.这是因为DownloadManger只允许download能处理的file而那些file没有对应的Activity处理的就会选择不download.具体的代码：
package com.android.providers.downloads;
Helpers.java

 /**
     * Creates a filename (where the file should be saved) from a uri.
     */
    public static DownloadFileInfo generateSaveFile(
            Context context,
            String url,
            String hint,
            String contentDisposition,
            String contentLocation,
            String mimeType,
            int destination,
            int contentLength) throws FileNotFoundException {

        /*
         * Don't download files that we won't be able to handle
         */
        if (destination == Downloads.DESTINATION_EXTERNAL
                || destination == Downloads.DESTINATION_CACHE_PARTITION_PURGEABLE) {
            if (mimeType == null) {
                if (Config.LOGD) {
                    Log.d(Constants.TAG, "external download with no mime type not allowed");
                }
                return new DownloadFileInfo(null, null, Downloads.STATUS_NOT_ACCEPTABLE);
            }
            if (!DrmRawContent.DRM_MIMETYPE_MESSAGE_STRING.equalsIgnoreCase(mimeType)) {
                // Check to see if we are allowed to download this file. Only files
                // that can be handled by the platform can be downloaded.
                // special case DRM files, which we should always allow downloading.
                Intent intent = new Intent(Intent.ACTION_VIEW);
                
                // We can provide data as either content: or file: URIs,
                // so allow both.  (I think it would be nice if we just did
                // everything as content: URIs)
                // Actually, right now the download manager's UId restrictions
                // prevent use from using content: so it's got to be file: or
                // nothing 

                PackageManager pm = context.getPackageManager();
                intent.setDataAndType(Uri.fromParts("file", "", null), mimeType);
                ResolveInfo ri = pm.resolveActivity(intent, PackageManager.MATCH_DEFAULT_ONLY);
                //Log.i(Constants.TAG, "*** FILENAME QUERY " + intent + ": " + list);

                if (ri == null) {
                    if (Config.LOGD) {
                        Log.d(Constants.TAG, "no handler found for type " + mimeType);
                    }
                    return new DownloadFileInfo(null, null, Downloads.STATUS_NOT_ACCEPTABLE);
                }
            }
        }
        String filename = chooseFilename(
                url, hint, contentDisposition, contentLocation, destination);

        // Split filename between base and extension
        // Add an extension if filename does not have one
        String extension = null;
        int dotIndex = filename.indexOf('.');
        if (dotIndex < 0) {
            extension = chooseExtensionFromMimeType(mimeType, true);
        } else {
            extension = chooseExtensionFromFilename(
                    mimeType, destination, filename, dotIndex);
            filename = filename.substring(0, dotIndex);
        }

中的

PackageManager pm = context.getPackageManager();
                intent.setDataAndType(Uri.fromParts("file", "", null), mimeType);
                ResolveInfo ri = pm.resolveActivity(intent, PackageManager.MATCH_DEFAULT_ONLY);
                //Log.i(Constants.TAG, "*** FILENAME QUERY " + intent + ": " + list);

                if (ri == null) {
                    if (Config.LOGD) {
                        Log.d(Constants.TAG, "no handler found for type " + mimeType);
                    }
                    return new DownloadFileInfo(null, null, Downloads.STATUS_NOT_ACCEPTABLE);

就是对这个的处理。
若你要使它能download你想要download的任何类型的file,你可以将上面这段代码去掉。也就是对DownloadManager进行修改。或许你不想修改DownlodManager进行修改，那么你可以增加一个Activity来处理你的特定类型的file。这样DownloadManager就能找到这个Activtiy,就能下载了。比如：

<activity android:name=".ViewDownload" android:label="@string/app_name">
			<intent-filter>
				<action android:name="android.intent.action.VIEW" />
				<category android:name="android.intent.category.DEFAULT" />
				<data android:mimeType="application/epub+zip" />
			</intent-filter>

		</activity>

这样就能下载epub这样file了。
具体的你可以参考这篇文章：
http://a.77mi.com/Thread/view/id-14016