com.googlecode.fascinator.indexer.RuleManager.java Source code

Introduction

Here is the source code for com.googlecode.fascinator.indexer.RuleManager.java

Source

/* 
 * The Fascinator - Indexer
 * Copyright (C) 2009 University of Southern Queensland
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 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.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
package com.googlecode.fascinator.indexer;

import com.googlecode.fascinator.api.indexer.rule.Rule;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Manages and controls the processing of indexing rules
 * 
 * @author Oliver Lucido
 */
public class RuleManager {

    private Logger log = LoggerFactory.getLogger(RuleManager.class);

    private List<Rule> rules;

    private List<File> tempFiles;

    private File workDir;

    private boolean cancelled;

    public RuleManager() {
        rules = new ArrayList<Rule>();
        workDir = new File(System.getProperty("java.io.tmpdir"));
        cancelled = false;
    }

    public void setWorkDir(File workDir) {
        this.workDir = workDir;
    }

    public void add(Rule rule) {
        rules.add(rule);
    }

    public void remove(Rule rule) {
        rules.remove(rule);
    }

    public boolean cancelled() {
        return cancelled;
    }

    public void run(Reader in, Writer out) throws IOException {
        File tmpFile;
        Reader tmpIn = in;
        Writer tmpOut = null;
        OutputStream tmpOutStream;
        cancelled = false;
        for (Rule rule : rules) {
            try {
                tmpFile = createTempFile("rule", ".xml");
                tmpOutStream = new FileOutputStream(tmpFile);
                tmpOut = new OutputStreamWriter(tmpOutStream, "UTF-8");
                rule.run(tmpIn, tmpOut);
                tmpOut.close();
                tmpOutStream.close();
                tmpIn.close();
                tmpIn = new InputStreamReader(new FileInputStream(tmpFile), "UTF-8");
            } catch (Exception e) {
                if (rule.isRequired()) {
                    cancelled = true;
                    log.error("Stopping since " + rule + " failed: ", e);
                    break;
                } else {
                    log.warn("Rule " + rule + " failed: " + e.getMessage());
                    e.printStackTrace();
                }
            }
        }
        if (!cancelled) {
            IOUtils.copy(tmpIn, out);
        }
        tmpIn.close();
        out.close();
        cleanupTempFiles();
    }

    private File createTempFile(String prefix, String postfix) throws IOException {
        File tempFile = File.createTempFile(prefix, postfix, workDir);
        tempFile.deleteOnExit();
        if (tempFiles == null) {
            tempFiles = Collections.synchronizedList(new ArrayList<File>());
        }
        tempFiles.add(tempFile);
        return tempFile;
    }

    private void cleanupTempFiles() {
        if (tempFiles != null) {
            for (File tempFile : tempFiles) {
                if (tempFile.exists()) {
                    tempFile.delete();
                }
            }
            tempFiles = null;
        }
    }
}