org.wso2.carbon.hdfs.mgt.ui.GetHDFSItemContentProcessor.java Source code

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Here is the source code for org.wso2.carbon.hdfs.mgt.ui.GetHDFSItemContentProcessor.java

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/*
 * Copyright (c) 2006, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 * 
 * 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 org.wso2.carbon.hdfs.mgt.ui;

import java.io.InputStream;

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

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.wso2.carbon.hdfs.mgt.stub.fs.xsd.HDFSFileContent;
import org.wso2.carbon.registry.core.exceptions.RegistryException;

public class GetHDFSItemContentProcessor {

    private static final Log log = LogFactory.getLog(GetHDFSItemContentProcessor.class);

    public static void getContent(HttpServletRequest request, HttpServletResponse response, ServletConfig config)
            throws Exception {

        try {
            HDFSFileOperationAdminClient client = new HDFSFileOperationAdminClient(config.getServletContext(),
                    request.getSession());
            String path = request.getParameter("path");
            if (path == null) {
                String msg = "Could not get the resource content. Path is not specified.";
                log.error(msg);
                response.setStatus(400);
                return;
            }

            HDFSFileContent fileContent = client.downloadFile(path);
            String fileName = path.substring(path.lastIndexOf("/") + 1, path.length());

            InputStream contentStream = null;
            if (fileContent.getDataHandler() != null) {
                contentStream = fileContent.getDataHandler().getInputStream();
            } else {
                String msg = "The resource content was empty.";
                log.error(msg);
                response.setStatus(204);
                return;
            }

            response.setContentType("application/download");
            response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");

            if (contentStream != null) {

                ServletOutputStream servletOutputStream = null;
                try {
                    servletOutputStream = response.getOutputStream();

                    byte[] contentChunk = new byte[1024];
                    int byteCount;
                    while ((byteCount = contentStream.read(contentChunk)) != -1) {
                        servletOutputStream.write(contentChunk, 0, byteCount);
                    }

                    response.flushBuffer();
                    servletOutputStream.flush();

                } finally {
                    contentStream.close();

                    if (servletOutputStream != null) {
                        servletOutputStream.close();
                    }
                }
            }
        } catch (HdfsMgtUiComponentException ex) {
            String msg = "Failed to get resource content. " + ex.getMessage();
            log.error(msg, ex);
            response.setStatus(500);
            return;

        } catch (RegistryException e) {
            String msg = "Failed to get resource content. " + e.getMessage();
            log.error(msg, e);
            response.setStatus(500);
            return;
        }
    }
}