com.prowidesoftware.swift.io.AbstractReader.java Source code

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Here is the source code for com.prowidesoftware.swift.io.AbstractReader.java

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/*******************************************************************************
 * Copyright (c) 2016 Prowide Inc.
 *
 *     This program is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU Lesser General Public License as 
 *     published by the Free Software Foundation, either version 3 of the 
 *     License, or (at your option) any later version.
 *
 *     This program is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
 *     
 *     Check the LGPL at <http://www.gnu.org/licenses/> for more details.
 *******************************************************************************/
package com.prowidesoftware.swift.io;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;
import java.util.Iterator;
import java.util.logging.Logger;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.Validate;

import com.prowidesoftware.swift.io.parser.SwiftParser;
import com.prowidesoftware.swift.model.SwiftMessage;
import com.prowidesoftware.swift.model.mt.AbstractMT;

/**
 * Base class for message reader iterators.
 * 
 * @author sebastian@prowidesoftware.com
 * @since 7.8
 */
public abstract class AbstractReader implements Iterator<String>, Iterable<String> {
    private static final Logger log = Logger.getLogger(AbstractReader.class.getName());
    protected Reader reader = null;

    /**
     * Constructs a reader to read messages from a given Reader instance
     */
    public AbstractReader(Reader r) {
        this.reader = r;
    }

    /**
     * Constructs a reader to read messages from a string
     * @throws IllegalArgumentException if string is <code>null</code>
     */
    public AbstractReader(final String string) {
        Validate.notNull(string, "string must not be null");
        this.reader = new StringReader(string);
    }

    /**
     * Constructs a reader to read messages from a stream
     * @throws IllegalArgumentException if stream is <code>null</code>
     */
    public AbstractReader(final InputStream stream) {
        Validate.notNull(stream, "stream must not be null");
        this.reader = new InputStreamReader(stream);
    }

    /**
     * Constructs a reader to read messages from a file
     * @throws IllegalArgumentException if file is <code>null</code>
     */
    public AbstractReader(final File file) throws FileNotFoundException {
        Validate.notNull(file, "file must not be null");
        Validate.isTrue(file.exists(), "Non existent file: " + file.getAbsolutePath());
        this.reader = new FileReader(file);
    }

    public Iterator<String> iterator() {
        return this;
    }

    public abstract String next();

    public void remove() {
        throw new UnsupportedOperationException("remove not avaiable in this implementation");
    }

    /**
     * Reads the next raw content from the iterator and returns the message parsed into an MT.
     * <br /><br />
     * Important Note: Since MTnnn model clases are implemented only for user messages 
     * (categories 1 to 9) if an ACK/NAK (F21) message is found, the MT following the system 
     * message is returned (not the ACK/NAK).
     * <br />
     * For FIN and system messages support use {@link #nextSwiftMessage()} 
     * 
     * @return parsed message or null if content is blank
     * @throws IOException if the message content cannot be parsed into an MT
     */
    public AbstractMT nextMT() throws IOException {
        SwiftMessage candidate = nextSwiftMessage();
        if (candidate != null) {
            if (candidate.isSystemMessage()) {
                final String fin = candidate.getUnparsedTexts().getAsFINString();
                SwiftParser parser = new SwiftParser(new ByteArrayInputStream(fin.getBytes()));
                return parser.message().toMT();
            } else {
                return candidate.toMT();
            }
        }
        return null;
    }

    /**
     * Reads the next raw content from the iterator and returns the message parsed as a generic SwiftMessage.
     * 
     * @return parsed message or null if content is blank
     * @throws IOException if the message content cannot be parsed into an SwiftMessage
     * @since 7.8.3
     */
    public SwiftMessage nextSwiftMessage() throws IOException {
        final String msg = next();
        if (StringUtils.isNotBlank(msg)) {
            SwiftParser parser = new SwiftParser(new ByteArrayInputStream(msg.getBytes()));
            return parser.message();
        }
        log.warning("Message content cannot be parsed as MT");
        return null;
    }

}