org.wso2.carbon.mediator.transform.stream.ElementInputStream.java Source code

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Here is the source code for org.wso2.carbon.mediator.transform.stream.ElementInputStream.java

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/*
 * Copyright (c) 2006, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 * 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.wso2.carbon.mediator.transform.stream;

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

import javax.xml.stream.XMLStreamException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.wso2.carbon.mediator.transform.stream.IOElementPipe;

/**
 * This class extends from InputStream.
 * The data is retrieved from the IOElementPipe when reading from this class.
 */
public class ElementInputStream extends InputStream {

    /** This pipe is used to get data to read*/
    private IOElementPipe pipe;

    private static final Log log = LogFactory.getLog(ElementInputStream.class);

    /**
     * Constructor which creates ElementInputStream object with IOElementPipe object.
     * @param pipe
     */
    public ElementInputStream(IOElementPipe pipe) {
        this.pipe = pipe;
    }

    /**
     * Read data to byte array by getting data from pipe.
     */
    public synchronized int read(byte[] b, int off, int len) {
        if (b == null) {
            throw new NullPointerException("Null byte array passed to read data");
        } else if (off < 0 || len < 0 || len > b.length - off) {
            throw new IndexOutOfBoundsException("IndexOutOfBoundException when reading data");
        }

        if (len <= 0) {
            return 0;
        }
        try {
            // Get data from the pipe
            byte[] btemp = this.pipe.getData(len, off);
            if (len > btemp.length) {
                len = btemp.length;
            }
            if (btemp.length == 0) {
                this.pipe.closeConnections();
                return -1;
            }
            System.arraycopy(btemp, 0, b, off, len);
        } catch (XMLStreamException e) {
            String errMessage = "Error in writting xml events";
            log.error(errMessage);
        } catch (IOException e) {
            String errMessage = "Error in closing outputstream";
            log.error(errMessage);
        }
        return len;
    }

    @Override
    public int read() throws IOException {
        byte[] buf = new byte[1];
        int count = read(buf, 0, 1);
        if (count > 0) {
            return buf[0];
        } else {
            return -1;
        }
    }

}