org.latticesoft.util.common.FileIterator.java Source code

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Here is the source code for org.latticesoft.util.common.FileIterator.java

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/*
 * Copyright 2004 Senunkan Shinryuu
 *
 * 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.
 *
 * Created on Mar 23, 2006
 *
 */
package org.latticesoft.util.common;

import java.util.Iterator;
import java.io.*;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class FileIterator implements Iterator {

    private static final Log log = LogFactory.getLog(FileIterator.class);
    private File file = null;
    private InputStream is = null;
    private InputStreamReader isr = null;
    private LineNumberReader lnr = null;
    private String filename;
    private boolean active = false;
    private String buffer = null;

    private FileIterator() {
    }

    public FileIterator(String filename) {
        try {
            File file = new File(filename);
            is = new FileInputStream(file);
            isr = new InputStreamReader(is);
            lnr = new LineNumberReader(isr);
            active = true;
        } catch (Exception e) {
            if (log.isErrorEnabled()) {
                log.error(e);
            }
        }
    }

    /** @return Returns the filename. */
    public String getFilename() {
        return (this.filename);
    }

    /** @param filename The filename to set. */
    public void setFilename(String filename) {
        this.filename = filename;
    }

    /**
     * No implementation
     */
    public void remove() {
        if (file != null)
            file.canRead(); // dummy
    }

    public boolean hasNext() {
        if (!active)
            return false;
        try {
            buffer = lnr.readLine();
        } catch (Exception e) {
        }
        if (buffer != null)
            return true;
        return false;
    }

    public Object next() {
        if (!active)
            return null;
        return buffer;
    }

    public void close() {
        try {
            this.lnr.close();
        } catch (Exception e) {
        }
        try {
            this.isr.close();
        } catch (Exception e) {
        }
        try {
            this.is.close();
        } catch (Exception e) {
        }
        lnr = null;
        isr = null;
        is = null;
        file = null;
    }

    /* (non-Javadoc)
     * @see java.lang.Object#finalize()
     */
    protected void finalize() throws Throwable {
        // TODO Auto-generated method stub
        super.finalize();
        this.close();
    }

}