org.n52.wps.server.request.strategy.LazyHttpInputStream.java Source code

Introduction

Here is the source code for org.n52.wps.server.request.strategy.LazyHttpInputStream.java

Source

/**
 * Copyright (C) 2007 - 2014 52North Initiative for Geospatial Open Source
 * Software GmbH
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 *
 * If the program is linked with libraries which are licensed under one of
 * the following licenses, the combination of the program with the linked
 * library is not considered a "derivative work" of the program:
 *
 *        Apache License, version 2.0
 *        Apache Software License, version 1.0
 *        GNU Lesser General Public License, version 3
 *        Mozilla Public License, versions 1.0, 1.1 and 2.0
 *        Common Development and Distribution License (CDDL), version 1.0
 *
 * Therefore the distribution of the program linked with libraries licensed
 * under the aforementioned licenses, is permitted by the copyright holders
 * if the distribution is compliant with both the GNU General Public
 * License version 2 and the aforementioned licenses.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 * Public License for more details.
 */
package org.n52.wps.server.request.strategy;

import java.io.IOException;
import java.io.InputStream;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DecompressingHttpClient;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicHeader;
import org.n52.wps.server.request.InputHandler;

/**
 * An extension of an Input Stream with HTTP Connection abilities.
 * Uses an {@link InputStream} internally. HTTP connection is established
 * in a lazy fashion, i.e. on first read attempt.
 * 
 * This class shall prevent timeout issues with I/O streaming in the WPS framework.
 * 
 * @deprecated alternative implementation now used, featuring {@link ReferenceInputStream} and
 * corresponding adjustments in {@link InputHandler}
 * 
 * @author Matthias Mueller, TU Dresden
 *
 */
@Deprecated
public class LazyHttpInputStream extends InputStream {

    private InputStream is;
    private boolean initDone = false;

    // connection parameters
    final boolean useHttpGet;
    final String dataURLString;
    final String body;
    final String mimeType;

    /**
     * Constructor for HTTP/POST
     * 
     * @param dataURLString
     * @param body
     * @param mimeType
     */
    public LazyHttpInputStream(final String dataURLString, final String body, final String mimeType) {
        this.dataURLString = dataURLString;
        this.body = body;
        this.mimeType = mimeType;
        useHttpGet = false;
    }

    /**
     * Constructor for HTTP/GET
     * 
     * @param dataURLString
     * @param body
     * @param mimeType
     */
    public LazyHttpInputStream(final String dataURLString, final String mimeType) {
        this.dataURLString = dataURLString;
        this.body = null;
        this.mimeType = mimeType;
        useHttpGet = true;
    }

    /**
     * Private init method that makes HTTP connections.
     * 
     * @throws IOException
     */
    private final void init() throws IOException {
        if (useHttpGet) {
            is = httpGet(dataURLString, mimeType);
        } else {
            is = httpPost(dataURLString, body, mimeType);
        }

        initDone = true;
    }

    @Override
    public int read() throws IOException {
        if (!initDone) {
            init();
        }

        return is.read();
    }

    @Override
    public int available() throws IOException {
        if (!initDone) {
            init();
        }
        return is.available();
    }

    @Override
    public void close() throws IOException {
        if (!initDone) {
            init();
        }
        is.close();
    }

    @Override
    public synchronized void mark(int readlimit) {
        if (!initDone) {
            try {
                init();
            } catch (IOException e) {
                // silent catch
            }
        }
        is.mark(readlimit);
    }

    @Override
    public synchronized void reset() throws IOException {
        if (!initDone) {
            init();
        }
        is.reset();
    }

    @Override
    public boolean markSupported() {
        if (!initDone) {
            // silent catch
        }
        return is.markSupported();
    }

    /**
     * Make a GET request using mimeType and href
     * 
     * TODO: add support for autoretry, proxy
     */
    private static InputStream httpGet(final String dataURLString, final String mimeType) throws IOException {
        HttpClient backend = new DefaultHttpClient();
        DecompressingHttpClient httpclient = new DecompressingHttpClient(backend);

        HttpGet httpget = new HttpGet(dataURLString);

        if (mimeType != null) {
            httpget.addHeader(new BasicHeader("Content-type", mimeType));
        }

        HttpResponse response = httpclient.execute(httpget);
        HttpEntity entity = response.getEntity();
        return entity.getContent();
    }

    /**
     * Make a POST request using mimeType and href
     * 
     * TODO: add support for autoretry, proxy
     */
    private static InputStream httpPost(final String dataURLString, final String body, final String mimeType)
            throws IOException {
        HttpClient backend = new DefaultHttpClient();

        DecompressingHttpClient httpclient = new DecompressingHttpClient(backend);

        HttpPost httppost = new HttpPost(dataURLString);

        if (mimeType != null) {
            httppost.addHeader(new BasicHeader("Content-type", mimeType));
        }

        // set body entity
        HttpEntity postEntity = new StringEntity(body);
        httppost.setEntity(postEntity);

        HttpResponse response = httpclient.execute(httppost);
        HttpEntity resultEntity = response.getEntity();
        return resultEntity.getContent();
    }

}