org.seasar.mayaa.impl.source.ApplicationResourceSourceDescriptor.java Source code

Java tutorial

Introduction

Here is the source code for org.seasar.mayaa.impl.source.ApplicationResourceSourceDescriptor.java

Source

/*
 * Copyright 2004-2012 the Seasar Foundation and the Others.
 *
 * 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.seasar.mayaa.impl.source;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Date;

import javax.servlet.ServletContext;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.seasar.mayaa.FactoryFactory;
import org.seasar.mayaa.cycle.scope.ApplicationScope;
import org.seasar.mayaa.impl.ParameterAwareImpl;
import org.seasar.mayaa.impl.cycle.CycleUtil;
import org.seasar.mayaa.impl.util.IOUtil;
import org.seasar.mayaa.impl.util.StringUtil;

/**
 * ?Web?????File???Context???SourceDescriptor
 *
 * @author Taro KATO (Gluegent Inc.)
 */
public class ApplicationResourceSourceDescriptor extends ParameterAwareImpl
        implements ChangeableRootSourceDescriptor {

    private static final long serialVersionUID = -2775274363708858237L;
    static final Log LOG = LogFactory.getLog(ApplicationResourceSourceDescriptor.class);

    private transient ApplicationScope _application;

    /** File????????? */
    private transient URL _url;

    private transient String _systemID;

    public ApplicationResourceSourceDescriptor() {
        // do nothing.
    }

    // use while building ServiceProvider.
    public void setApplicationScope(ApplicationScope application) {
        if (application == null) {
            throw new IllegalArgumentException();
        }
        _application = application;
    }

    public ApplicationScope getApplicationScope() {
        if (_application == null) {
            _application = FactoryFactory.getApplicationScope();
        }
        return _application;
    }

    public void setRoot(String root) {
        // ignore
    }

    protected URL getURL() {
        if (_url == null) {
            String path = _systemID;
            if (StringUtil.isEmpty(path)) {
                path = "/";
            }
            // TODO ???ServletContext???????
            ServletContext context = (ServletContext) getApplicationScope().getUnderlyingContext();
            try {
                // TODO GAE for Java???null?????????...
                _url = context.getResource(path);
                if (_url == null) {
                    LOG.debug("NG. getResource failed. - " + path);
                } else {
                    LOG.debug("OK. getResource url succeed. - " + path);
                }
                return _url;
            } catch (MalformedURLException e) {
                throw new IllegalStateException("invalid: " + path);
            }
        }
        return _url;
    }

    /* (non-Javadoc)
     * @see org.seasar.mayaa.source.SourceDescriptor#exists()
     */
    public boolean exists() {
        URL url = getURL();
        if (url != null) {
            return true;
        }
        // GAE for Java _url?null???Stream???
        ServletContext context = (ServletContext) getApplicationScope().getUnderlyingContext();
        InputStream resourceAsStream = context.getResourceAsStream(_systemID);
        try {
            return resourceAsStream != null;
        } finally {
            try {
                if (resourceAsStream != null) {
                    resourceAsStream.close();
                }
            } catch (IOException e) {
                return false;
            }
        }
    }

    /* (non-Javadoc)
     * @see org.seasar.mayaa.source.SourceDescriptor#getInputStream()
     */
    public InputStream getInputStream() {
        return IOUtil.openStream(getURL());
    }

    /* (non-Javadoc)
     * @see org.seasar.mayaa.source.SourceDescriptor#getTimestamp()
     */
    public Date getTimestamp() {
        return new Date(IOUtil.getLastModified(getURL()));
    }

    /* (non-Javadoc)
     * @see org.seasar.mayaa.impl.ParameterAwareImpl#setSystemID()
     */
    public void setSystemID(String systemID) {
        if (!StringUtil.equals(_systemID, systemID)) {
            _systemID = systemID;
            _url = null;
        }
    }

    /* (non-Javadoc)
     * @see org.seasar.mayaa.impl.ParameterAwareImpl#getSystemID()
     */
    public String getSystemID() {
        return _systemID;
    }

    // for serialize

    private void readObject(java.io.ObjectInputStream in) throws java.io.IOException, ClassNotFoundException {
        in.defaultReadObject();
        _application = CycleUtil.getServiceCycle().getApplicationScope();
    }

}