org.alfresco.module.demoscripts.RandomSelectWebScript.java Source code

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Here is the source code for org.alfresco.module.demoscripts.RandomSelectWebScript.java

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package org.alfresco.module.demoscripts;

/**
 * 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.
 */

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.StringTokenizer;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.alfresco.model.ContentModel;
import org.alfresco.repo.model.Repository;
import org.alfresco.service.ServiceRegistry;
import org.alfresco.service.cmr.model.FileInfo;
import org.alfresco.service.cmr.repository.ContentReader;
import org.alfresco.service.cmr.repository.NodeRef;
import org.springframework.extensions.webscripts.AbstractWebScript;
import org.springframework.extensions.webscripts.WebScriptException;
import org.springframework.extensions.webscripts.WebScriptRequest;
import org.springframework.extensions.webscripts.WebScriptResponse;
import org.springframework.extensions.webscripts.servlet.WebScriptServletRequest;

public class RandomSelectWebScript extends AbstractWebScript {
    private static Random gen = new Random();
    private ServiceRegistry registry;
    private Repository repository;

    // for Spring injection
    public void setRepository(Repository repository) {
        this.repository = repository;
    }

    // for Spring injection
    public void setServiceRegistry(ServiceRegistry registry) {
        this.registry = registry;
    }

    public void execute(WebScriptRequest req, WebScriptResponse res) throws IOException {
        // get the referenced incoming node
        NodeRef rootNodeRef = getNodeRef(req);

        // draw a random child
        NodeRef childNodeRef = randomChild(rootNodeRef);

        // stream child back
        output(res, childNodeRef);
    }

    protected NodeRef randomChild(NodeRef rootNodeRef) {
        // count the number of children
        List<FileInfo> files = registry.getFileFolderService().listFiles(rootNodeRef);
        int fileCount = files.size();

        // draw random number
        int draw = gen.nextInt(fileCount);

        // our draw
        FileInfo fileInfo = files.get(draw);
        NodeRef nodeRef = fileInfo.getNodeRef();

        return nodeRef;
    }

    protected NodeRef getNodeRef(WebScriptRequest req) {
        // NOTE: This web script must be executed in a HTTP Servlet environment
        if (!(req instanceof WebScriptServletRequest)) {
            throw new WebScriptException("Content retrieval must be executed in HTTP Servlet environment");
        }
        HttpServletRequest httpReq = ((WebScriptServletRequest) req).getHttpServletRequest();

        // locate the root path
        String path = httpReq.getParameter("path");
        if (path == null) {
            path = "/images";
        }
        if (path.startsWith("/")) {
            path = path.substring(1);
        }

        // build a path elements list
        List<String> pathElements = new ArrayList<String>();
        StringTokenizer tokenizer = new StringTokenizer(path, "/");
        while (tokenizer.hasMoreTokens()) {
            String childName = tokenizer.nextToken();
            pathElements.add(childName);
        }

        // look up the child
        NodeRef nodeRef = null;
        try {
            NodeRef companyHomeRef = repository.getCompanyHome();
            nodeRef = registry.getFileFolderService().resolveNamePath(companyHomeRef, pathElements).getNodeRef();
        } catch (Exception ex) {
            throw new WebScriptException(HttpServletResponse.SC_NOT_FOUND, "Unable to locate path");
        }
        if (nodeRef == null) {
            throw new WebScriptException(HttpServletResponse.SC_NOT_FOUND, "Unable to locate path");
        }

        return nodeRef;
    }

    protected void output(WebScriptResponse res, NodeRef nodeRef) {
        // stream back
        try {
            ContentReader reader = registry.getContentService().getReader(nodeRef, ContentModel.PROP_CONTENT);
            reader.getContent(res.getOutputStream());
        } catch (Exception ex) {
            throw new WebScriptException("Unable to stream output");
        }
    }
}