org.apache.shindig.gadgets.rewrite.ConcatLinkRewriter.java Source code

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Here is the source code for org.apache.shindig.gadgets.rewrite.ConcatLinkRewriter.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.shindig.gadgets.rewrite;

import com.google.common.collect.Lists;

import org.apache.shindig.common.uri.Uri;
import org.apache.shindig.common.util.Utf8UrlCoder;
import org.apache.shindig.gadgets.servlet.ProxyBase;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.LinkedHashSet;
import java.util.List;

public class ConcatLinkRewriter {
    private final static int MAX_URL_LENGTH = 1500;

    private final ContentRewriterUris rewriterUris;

    private final ContentRewriterFeature rewriterFeature;
    private final Uri gadgetUri;
    private final String container;
    private final boolean debug;
    private final boolean ignoreCache;

    public ConcatLinkRewriter(ContentRewriterUris rewriterUris, Uri gadgetUri,
            ContentRewriterFeature rewriterFeature, String container, boolean debug, boolean ignoreCache) {
        this.rewriterUris = rewriterUris;
        this.rewriterFeature = rewriterFeature;
        this.gadgetUri = gadgetUri;
        this.container = container;
        this.debug = debug;
        this.ignoreCache = ignoreCache;
    }

    public List<Uri> rewrite(String mimeType, LinkedHashSet<Uri> uris) {
        String concatBase = getConcatBase(gadgetUri, rewriterFeature, mimeType, container);
        List<Uri> concatUris = Lists.newLinkedList();
        int paramIndex = 1;
        StringBuilder builder = null;
        int maxUriLen = MAX_URL_LENGTH + concatBase.length();
        try {
            int uriIx = 0;
            //
            for (Uri uri : uris) {
                String uriStr = uri.toString();
                if (builder != null && builder.length() + uriStr.length() > maxUriLen) {
                    // The next one will go over limit
                    concatUris.add(Uri.parse(builder.toString()));
                    builder = null;
                    paramIndex = 1;

                    // If the current uri is too long, simply don't rewrite, since
                    // concat is for developers benefit
                    if (uriStr.length() > MAX_URL_LENGTH) {
                        concatUris.add(uri);
                        continue;
                    }
                }

                if (paramIndex == 1) {
                    builder = new StringBuilder(concatBase);
                    if (debug)
                        builder.append("debug=1&");
                    if (ignoreCache)
                        builder.append("nocache=1&");
                    if (rewriterFeature.getExpires() != null) {
                        builder.append(ProxyBase.REFRESH_PARAM).append('=')
                                .append(rewriterFeature.getExpires().toString()).append('&');
                    }
                } else {
                    builder.append('&');
                }
                builder.append(paramIndex).append('=').append(URLEncoder.encode(uriStr, "UTF-8"));
                ++paramIndex;
                ++uriIx;
            }
            if (builder != null)
                concatUris.add(Uri.parse(builder.toString()));
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e);
        }
        return concatUris;
    }

    protected String getConcatBase(Uri gadgetUri, ContentRewriterFeature feature, String mimeType,
            String container) {
        String concatBaseNoGadget = rewriterUris.getConcatBase(container);
        return concatBaseNoGadget + ProxyBase.REWRITE_MIME_TYPE_PARAM + '=' + mimeType
                + ((gadgetUri == null) ? "" : "&gadget=" + Utf8UrlCoder.encode(gadgetUri.toString())) + "&fp="
                + feature.getFingerprint() + '&';
    }

}