wagon-provider-api/src/main/java/org/apache/maven/wagon/StreamWagon.java

/*
 * 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.maven.wagon;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.maven.wagon.authorization.AuthorizationException;
import org.apache.maven.wagon.events.TransferEvent;
import org.apache.maven.wagon.resource.Resource;

/**
 * Base class for wagon which provide stream based API.
 *
 * @author <a href="mailto:michal@codehaus.org">Michal Maczka</a>
 *
 */
public abstract class StreamWagon extends AbstractWagon implements StreamingWagon {
    // ----------------------------------------------------------------------
    //
    // ----------------------------------------------------------------------

    public abstract void fillInputData(InputData inputData)
            throws TransferFailedException, ResourceDoesNotExistException, AuthorizationException;

    public abstract void fillOutputData(OutputData outputData) throws TransferFailedException;

    public abstract void closeConnection() throws ConnectionException;

    // ----------------------------------------------------------------------
    //
    // ----------------------------------------------------------------------

    public void get(String resourceName, File destination)
            throws TransferFailedException, ResourceDoesNotExistException, AuthorizationException {
        getIfNewer(resourceName, destination, 0);
    }

    protected void checkInputStream(InputStream is, Resource resource) throws TransferFailedException {
        if (is == null) {
            TransferFailedException e = new TransferFailedException(
                    getRepository().getUrl() + " - Could not open input stream for resource: '" + resource + "'");
            fireTransferError(resource, e, TransferEvent.REQUEST_GET);
            throw e;
        }
    }

    public boolean getIfNewer(String resourceName, File destination, long timestamp)
            throws TransferFailedException, ResourceDoesNotExistException, AuthorizationException {
        boolean retValue = false;

        Resource resource = new Resource(resourceName);

        fireGetInitiated(resource, destination);

        resource.setLastModified(timestamp);

        InputStream is = getInputStream(resource);

        // always get if timestamp is 0 (ie, target doesn't exist), otherwise only if older than the remote file
        if (timestamp == 0 || timestamp < resource.getLastModified()) {
            retValue = true;

            checkInputStream(is, resource);

            getTransfer(resource, destination, is);
        } else {
            try {
                if (is != null) {
                    is.close();
                }
            } catch (final IOException e) {
                throw new TransferFailedException("Failure transferring " + resourceName, e);
            }
        }

        return retValue;
    }

    protected InputStream getInputStream(Resource resource)
            throws TransferFailedException, ResourceDoesNotExistException, AuthorizationException {
        InputData inputData = new InputData();

        inputData.setResource(resource);

        try {
            fillInputData(inputData);
        } catch (TransferFailedException e) {
            fireTransferError(resource, e, TransferEvent.REQUEST_GET);
            cleanupGetTransfer(resource);
            throw e;
        } catch (ResourceDoesNotExistException e) {
            fireTransferError(resource, e, TransferEvent.REQUEST_GET);
            cleanupGetTransfer(resource);
            throw e;
        } catch (AuthorizationException e) {
            fireTransferError(resource, e, TransferEvent.REQUEST_GET);
            cleanupGetTransfer(resource);
            throw e;
        } finally {
            if (inputData.getInputStream() == null) {
                cleanupGetTransfer(resource);
            }
        }

        return inputData.getInputStream();
    }

    // source doesn't exist exception
    public void put(File source, String resourceName)
            throws TransferFailedException, ResourceDoesNotExistException, AuthorizationException {
        Resource resource = new Resource(resourceName);

        firePutInitiated(resource, source);

        resource.setContentLength(source.length());

        resource.setLastModified(source.lastModified());

        OutputStream os = getOutputStream(resource);

        checkOutputStream(resource, os);

        putTransfer(resource, source, os, true);
    }

    protected void checkOutputStream(Resource resource, OutputStream os) throws TransferFailedException {
        if (os == null) {
            TransferFailedException e = new TransferFailedException(
                    getRepository().getUrl() + " - Could not open output stream for resource: '" + resource + "'");
            fireTransferError(resource, e, TransferEvent.REQUEST_PUT);
            throw e;
        }
    }

    protected OutputStream getOutputStream(Resource resource) throws TransferFailedException {
        OutputData outputData = new OutputData();

        outputData.setResource(resource);

        try {
            fillOutputData(outputData);
        } catch (TransferFailedException e) {
            fireTransferError(resource, e, TransferEvent.REQUEST_PUT);

            throw e;
        } finally {
            if (outputData.getOutputStream() == null) {
                cleanupPutTransfer(resource);
            }
        }

        return outputData.getOutputStream();
    }

    public boolean getIfNewerToStream(String resourceName, OutputStream stream, long timestamp)
            throws ResourceDoesNotExistException, TransferFailedException, AuthorizationException {
        boolean retValue = false;

        Resource resource = new Resource(resourceName);

        fireGetInitiated(resource, null);

        InputStream is = getInputStream(resource);

        // always get if timestamp is 0 (ie, target doesn't exist), otherwise only if older than the remote file
        if (timestamp == 0 || timestamp < resource.getLastModified()) {
            retValue = true;

            checkInputStream(is, resource);

            fireGetStarted(resource, null);

            getTransfer(resource, stream, is, true, Integer.MAX_VALUE);

            fireGetCompleted(resource, null);
        } else {
            try {
                if (is != null) {
                    is.close();
                }
            } catch (final IOException e) {
                throw new TransferFailedException("Failure transferring " + resourceName, e);
            }
        }

        return retValue;
    }

    public void getToStream(String resourceName, OutputStream stream)
            throws ResourceDoesNotExistException, TransferFailedException, AuthorizationException {
        getIfNewerToStream(resourceName, stream, 0);
    }

    public void putFromStream(InputStream stream, String destination)
            throws TransferFailedException, ResourceDoesNotExistException, AuthorizationException {
        Resource resource = new Resource(destination);

        firePutInitiated(resource, null);

        putFromStream(stream, resource);
    }

    public void putFromStream(InputStream stream, String destination, long contentLength, long lastModified)
            throws TransferFailedException, ResourceDoesNotExistException, AuthorizationException {
        Resource resource = new Resource(destination);

        firePutInitiated(resource, null);

        resource.setContentLength(contentLength);

        resource.setLastModified(lastModified);

        putFromStream(stream, resource);
    }

    protected void putFromStream(InputStream stream, Resource resource)
            throws TransferFailedException, AuthorizationException, ResourceDoesNotExistException {
        OutputStream os = getOutputStream(resource);

        checkOutputStream(resource, os);

        firePutStarted(resource, null);

        putTransfer(resource, stream, os, true);

        firePutCompleted(resource, null);
    }
}