org.apache.commons.io.input.ExtendedCloseShieldInputStream.java Source code

Introduction

Here is the source code for org.apache.commons.io.input.ExtendedCloseShieldInputStream.java

Source

/*
 * Copyright 2013 Lyor Goldstein
 * 
 * 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.apache.commons.io.input;

import java.io.InputStream;
import java.nio.channels.Channel;

import org.apache.commons.collections15.AbstractExtendedTransformer;
import org.apache.commons.collections15.ExtendedTransformer;

/**
 * Avoids the creation of a {@link ClosedInputStream} on each call to
 * {@link CloseShieldInputStream#close()}
 * @author Lyor G.
 * @since Jun 5, 2013 8:51:57 AM
 */
public class ExtendedCloseShieldInputStream extends CloseShieldInputStream implements Channel {
    public static final ExtendedTransformer<InputStream, ExtendedCloseShieldInputStream> CLOSE_SHIELD_INPUT = new AbstractExtendedTransformer<InputStream, ExtendedCloseShieldInputStream>(
            InputStream.class, ExtendedCloseShieldInputStream.class) {
        @Override
        public ExtendedCloseShieldInputStream transform(InputStream input) {
            if (input == null) {
                return null;
            } else {
                return new ExtendedCloseShieldInputStream(input);
            }
        }
    };

    public ExtendedCloseShieldInputStream(InputStream input) {
        super(input);
    }

    @Override
    public boolean isOpen() {
        if (this.in == ClosedInputStream.CLOSED_INPUT_STREAM) {
            return true;
        } else {
            return false;
        }
    }

    @Override
    public void close() {
        if (this.in != ClosedInputStream.CLOSED_INPUT_STREAM) {
            this.in = ClosedInputStream.CLOSED_INPUT_STREAM;
        }
    }

    /**
     * @param s The original {@link InputStream}
     * @param okToClose <code>true</code> if the original input stream
     * may be closed
     * @return The original stream if OK to close it, an {@link ExtendedCloseShieldInputStream}
     * wrapper otherwise
     */
    public static final InputStream resolveInputStream(InputStream s, boolean okToClose) {
        if (okToClose) {
            return s;
        } else {
            return new ExtendedCloseShieldInputStream(s);
        }
    }
}