ClientJNLPConfigData.java

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package org.glassfish.appclient.server.core.jws;

import com.sun.logging.LogDomains;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.text.MessageFormat;
import java.util.Collections;
import java.util.List;
import java.util.Properties;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Encapsulates the logic related to choosing which of the two possible
 * config files to use and handling the data within the selected file.
 */
class ClientJNLPConfigData {

    private static final String CONFIG_FILE_NAME = "client-jnlp-config.properties";
    private File previousConfigFileUsed = null;
    private File configFileFromDomain;
    private File configFileFromInstall;
    private long lastModified = -1;

    private Logger logger = LogDomains.getLogger(ClientJNLPConfigData.class, LogDomains.ACC_LOGGER);

    /**
     * Easier for the caller if we return empty lists rather than nulls if we cannot
     * locate either config file.
     */
    private List<XPathToDeveloperProvidedContentRefs> xPathsToDevContentRefs = Collections.EMPTY_LIST;
    private List<CombinedXPath> xPathsToCombinedContent = Collections.EMPTY_LIST;

    
    ClientJNLPConfigData(final File installConfigDir, final File domainConfigDir) {
        super();
        configFileFromInstall = new File(installConfigDir, CONFIG_FILE_NAME);
        configFileFromDomain = new File(domainConfigDir, CONFIG_FILE_NAME);
        ensureCurrent();
    }

    /**
     * Makes sure that the in-memory data is up-to-date wrt the on-disk
     * properties file - whether that's the domain's config file or the
     * installation's config file.
     */
    private void ensureCurrent() {
        final File configFile = chooseConfigFile();
        if (configFile == null) {
            lastModified = -1;
            xPathsToDevContentRefs = Collections.EMPTY_LIST;
            xPathsToCombinedContent = Collections.EMPTY_LIST;
            return;
        }
        if (lastModified < configFile.lastModified() || previousConfigFileUsed != configFile) {
            processConfigFile(configFile);
        }
    }

    /**
     * Chooses which config file to use, preferring the domain's config
     * file (if present and readable) and falling back to the
     * installation's file.
     * <p>
     * The method logs a warning if finds but cannot read the domain's
     * config file (we assume in that case that the administrator intended for that file
     * to be used but, alas, we cannot read it).  It logs a severe error
     * if there is no JNLP config file for the domain and it cannot locate
     * or read the installation's file, which should always be usable.
     *
     * @return the config file to be used; null if neither the domain's nor
     * the installation's config file exists and is readable
     */
    private File chooseConfigFile() {
        File result = checkExistenceAndReadability(configFileFromDomain, Level.WARNING);
        if (result == null) {
            result = checkExistenceAndReadability(configFileFromInstall, Level.SEVERE);
            if (result == null && !configFileFromInstall.exists()) {
                /*
                 * Complain separately if the installation's config file
                 * does not exist.
                 */
                logErrorNonExistentConfig(configFileFromInstall);
            }
        }
        if (result != null && previousConfigFileUsed != null && result != previousConfigFileUsed) {
            logUsingDifferentConfigFile(result);
        }
        return result;
    }

    private File checkExistenceAndReadability(final File f, final Level logLevel) {
        File result = null;
        if (f.exists()) {
            if (f.canRead()) {
                result = f;
            } else {
                logErrorConfigExistsButCannotRead(logLevel, f);
            }
        }
        return result;
    }

    private void logErrorConfigExistsButCannotRead(final Level level, final File f) {
        logger.log(level, "enterprise.deployment.appclient.jws.clientJNLPConfigFileUnreadable", f.getAbsolutePath());
    }

    private void logErrorNonExistentConfig(final File f) {
        logger.log(Level.SEVERE, "enterprise.deployment.appclient.jws.clientJNLPConfigFileMissing", f.getAbsolutePath());
    }

    private void logUsingDifferentConfigFile(final File f) {
        logger.log(Level.FINE, "enterprise.deployment.appclient.jws.clientJNLPConfigChangeFile", f.getAbsolutePath());
    }

    List<XPathToDeveloperProvidedContentRefs> xPathsToDevContentRefs() {
        ensureCurrent();
        return xPathsToDevContentRefs;
    }

    List<CombinedXPath> xPathsToCombinedContent() {
        ensureCurrent();
        return xPathsToCombinedContent;
    }

    private void processConfigFile(final File configFile) {
        final Properties p = new Properties();
        InputStream is = null;
        try {
            is = new BufferedInputStream(new FileInputStream(configFile));
            p.load(is);
            final List<XPathToDeveloperProvidedContentRefs> newRefsToContent = prepareRefsToContent(p);
            final List<CombinedXPath> newCombinedXPaths = prepareCombinedXPaths(p);
            /*
             * Now that everything seems to have worked, assign the newly-computed
             * values to the fields.
             */
            xPathsToDevContentRefs = newRefsToContent;
            xPathsToCombinedContent = newCombinedXPaths;
            lastModified = configFile.lastModified();
            previousConfigFileUsed = configFile;
            logger.log(Level.FINE, "enterprise.deployment.appclient.jws.clientJNLPConfigLoad", configFile.getAbsolutePath());
        } catch (Exception e) {
            final String fmt = logger.getResourceBundle().getString("enterprise.deployment.appclient.jws.clientJNLPConfigProcError");
            final String msg = MessageFormat.format(fmt, configFile.getAbsolutePath());
            logger.log(Level.SEVERE, msg, e);
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException ex) {
                    throw new RuntimeException(ex);
                }
            }
        }
    }

    private List<XPathToDeveloperProvidedContentRefs> prepareRefsToContent(final Properties p) {
        final List<XPathToDeveloperProvidedContentRefs> result =
                XPathToDeveloperProvidedContentRefs.parse(p);
        return result;
    }

    private List<CombinedXPath> prepareCombinedXPaths(final Properties p) {
        final List<CombinedXPath> result = CombinedXPath.parse(p);
        return result;
    }

    
}