org.apache.wicket.util.resource.AbstractStringResourceStream.java Source code

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Here is the source code for org.apache.wicket.util.resource.AbstractStringResourceStream.java

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/*
 * 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.wicket.util.resource;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;

import org.apache.wicket.util.io.IOUtils;
import org.apache.wicket.util.io.Streams;
import org.apache.wicket.util.lang.Bytes;
import org.apache.wicket.util.string.Strings;
import org.apache.wicket.util.time.Time;

/**
 * Base class for string resources.
 * 
 * @author Jonathan Locke
 */
public abstract class AbstractStringResourceStream extends AbstractResourceStream implements IStringResourceStream {
    private static final long serialVersionUID = 1L;

    /** The content-type applied in case the resource stream's default constructor is used */
    public static final String DEFAULT_CONTENT_TYPE = "text";

    /** Charset name for resource */
    private String charsetName;

    /** MIME content type */
    private final String contentType;

    /** The last time this stylesheet was modified */
    private Time lastModified = null;

    /**
     * Constructor.
     */
    public AbstractStringResourceStream() {
        this(DEFAULT_CONTENT_TYPE);
    }

    /**
     * Constructor.
     * 
     * @param contentType
     *            The mime type of this resource, such as "image/jpeg" or "text/html"
     */
    public AbstractStringResourceStream(final String contentType) {
        // TODO null for contentType is allowed? or should the default be applied instead?
        this.contentType = contentType;

        lastModified = Time.now();
    }

    /**
     * @return This resource as a String.
     */
    @Override
    public String asString() {
        Reader reader = null;
        try {
            if (charsetName == null) {
                reader = new InputStreamReader(getInputStream());
            } else {
                reader = new InputStreamReader(getInputStream(), getCharset());
            }
            return Streams.readString(reader);
        } catch (IOException e) {
            throw new RuntimeException("Unable to read resource as String", e);
        } catch (ResourceStreamNotFoundException e) {
            throw new RuntimeException("Unable to read resource as String", e);
        } finally {
            IOUtils.closeQuietly(reader);
            IOUtils.closeQuietly(this);
        }
    }

    /**
     * @return Charset for resource
     */
    protected Charset getCharset() {
        // java.nio.Charset is not serializable so we can only store the name
        return (charsetName != null) ? Charset.forName(charsetName) : null;
    }

    /**
     * Sets the character set used for reading this resource.
     * 
     * @param charset
     *            Charset for component
     */
    @Override
    public void setCharset(final Charset charset) {
        // java.nio.Charset itself is not serializable so we can only store the name
        charsetName = (charset != null) ? charset.name() : null;
    }

    /**
     * @see org.apache.wicket.util.resource.IResourceStream#close()
     */
    @Override
    public void close() throws IOException {
    }

    /**
     * @see org.apache.wicket.util.resource.IResourceStream#getContentType()
     */
    @Override
    public String getContentType() {
        return contentType;
    }

    /**
     * @see org.apache.wicket.util.resource.IResourceStream#getInputStream()
     */
    @Override
    public InputStream getInputStream() throws ResourceStreamNotFoundException {
        final byte[] bytes;
        if (getCharset() != null) {
            try {
                bytes = getString().getBytes(getCharset().name());
            } catch (UnsupportedEncodingException e) {
                throw new ResourceStreamNotFoundException("Could not encode resource", e);
            }
        } else {
            bytes = getString().getBytes();
        }
        return new ByteArrayInputStream(bytes);
    }

    /**
     * @see org.apache.wicket.util.watch.IModifiable#lastModifiedTime()
     */
    @Override
    public Time lastModifiedTime() {
        return lastModified;
    }

    /**
     * @param lastModified
     *            The lastModified to set.
     */
    public void setLastModified(final Time lastModified) {
        this.lastModified = lastModified;
    }

    /**
     * @return The string resource
     */
    protected abstract String getString();

    @Override
    public final Bytes length() {
        int lengthInBytes = Strings.lengthInBytes(getString(), getCharset());
        return Bytes.bytes(lengthInBytes);
    }
}