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package jnlp.sample.servlet;
import javax.servlet.ServletContext;
import java.net.URL;
import java.io.File;
import java.io.IOException;
import java.net.URLConnection;
import java.util.*;

/**
 *  A JnlpResource encapsulate the information about a resource that is
 *  needed to process a JNLP Download Request.
 *
 *  The pattern matching arguments are: name, version-id, os, arch, and locale.
 *
 *  The outgoing arguments are:
 *     - path to resource in (WAR File)
 *     - product version-id (Version-id to return or null. Typically same as version-id above)
 *     - mime-type for content
 *     - lastModified date of WAR file resource
 *
 */
public class JnlpResource {
    private static final String JNLP_MIME_TYPE      = "application/x-java-jnlp-file";
    private static final String JAR_MIME_TYPE       = "application/x-java-archive";

    private static final String JAR_MIME_TYPE_NEW   = "application/java-archive";

    // Default extension for the JNLP file
    private static final String JNLP_EXTENSION      = ".jnlp";
    private static final String JAR_EXTENSION       = ".jar";

    private static String _jnlpExtension = JNLP_EXTENSION;
    private static String _jarExtension = JAR_EXTENSION;

    public static void setDefaultExtensions(String jnlpExtension, String jarExtension) {
        if (jnlpExtension != null && jnlpExtension.length() > 0) {
            if (!jnlpExtension.startsWith(".")) jnlpExtension = "." + jnlpExtension;
            _jnlpExtension = jnlpExtension;
        }
        if (jarExtension != null && jarExtension.length() > 0) {
            if (!jarExtension .startsWith(".")) jarExtension  = "." + jarExtension ;
            _jarExtension = jarExtension;
        }
    }

    /* Pattern matching arguments */
    private String _name;         // Name of resource with path (this is the same as path for non-version based)
    private String _versionId;    // Version-id for resource, or null if none
    private String[] _osList;     // List of OSes for which resource should be returned
    private String[] _archList;   // List of architectures for which the resource should be returned
    private String[] _localeList; // List of locales for which the resource should be returned
    /* Information used for reply */
    private String _path;            // Path to resource in WAR file (unique)
    private URL    _resource;        // URL to resource in WAR file (unique - same as above really)
    private long   _lastModified;    // Last modified in WAR file
    private String _mimeType;        // Mime-type for resource
    private String _returnVersionId; // Version Id to return
    private String _encoding;        // Accept encoding

    public JnlpResource(ServletContext context, String path) {
        this(context, null, null, null, null, null, path, null);
    }

    public JnlpResource(ServletContext context,
                        String name,
                        String versionId,
                        String[] osList,
                        String[] archList,
                        String[] localeList,
                        String path,
                        String returnVersionId) {
        this(context, name, versionId, osList, archList, localeList, path,
             returnVersionId, null);
    }

    public JnlpResource(ServletContext context,
                        String name,
                        String versionId,
                        String[] osList,
                        String[] archList,
                        String[] localeList,
                        String path,
                        String returnVersionId,
                        String encoding) {
        // Matching arguments
        _encoding = encoding;
        _name = name;
        _versionId = versionId;
        _osList = osList;
        _archList = archList;
        _localeList = localeList;

        _returnVersionId = returnVersionId;

        /* Check for existance and get last modified timestamp */
        try {
            String orig_path = path.trim();
            String search_path = orig_path;
            _resource = context.getResource(orig_path);
            _mimeType = getMimeType(context, orig_path);
            if (_resource != null) {

                boolean found = false;
                // pack200 compression
                if (encoding != null && _mimeType != null &&
                    (_mimeType.compareTo(JAR_MIME_TYPE) == 0 || _mimeType.compareTo(JAR_MIME_TYPE_NEW) == 0) &&
                    encoding.toLowerCase().indexOf(DownloadResponse.PACK200_GZIP_ENCODING) > -1){
                    search_path = orig_path + ".pack.gz";
                    _resource = context.getResource(search_path);
                    // Get last modified time
                    if (_resource != null) {
                        _lastModified = getLastModified(context, _resource, search_path);
                        if (_lastModified != 0) {
                            _path = search_path;
                            found = true;
                        } else {
                            _resource = null;
                        }
                    }
                }

                // gzip compression
                if (found == false && encoding != null &&
                    encoding.toLowerCase().indexOf(DownloadResponse.GZIP_ENCODING) > -1){
                    search_path = orig_path + ".gz";
                    _resource = context.getResource(search_path);
                    // Get last modified time
                    if (_resource != null) {
                        _lastModified = getLastModified(context, _resource, search_path);
                        if (_lastModified != 0) {
                            _path = search_path;
                            found = true;
                        } else {
                            _resource = null;
                        }
                    }
                }

                if (found == false) {
                    // no compression
                    search_path = orig_path;
                    _resource = context.getResource(search_path);
                    // Get last modified time
                    if (_resource != null) {
                        _lastModified = getLastModified(context, _resource, search_path);
                        if (_lastModified != 0) {
                            _path = search_path;
                            found = true;
                        } else {
                            _resource = null;
                        }
                    }
                }
            }
        } catch(IOException ioe) {
            _resource = null;
        }
    }

    long getLastModified(ServletContext context, URL resource, String path) {
        long lastModified = 0;
        URLConnection conn;
        try {
            // Get last modified time
            conn = resource.openConnection();
            lastModified = conn.getLastModified();
        } catch (Exception e) {
            // do nothing
        }

        if (lastModified == 0) {
            // Arguably a bug in the JRE will not set the lastModified for file URLs, and
            // always return 0. This is a workaround for that problem.
            String filepath = context.getRealPath(path);
            if (filepath != null) {
                File f = new File(filepath);
                if (f.exists()) {
                    lastModified = f.lastModified();
                }
            }
        }
        return lastModified;
    }

    /* Get resource specific attributes */
    public String getPath() { return _path; }
    public URL getResource() { return _resource; }
    public String getMimeType() { return _mimeType; }
    public long getLastModified() { return _lastModified; }
    public boolean exists() { return _resource != null; }
    public boolean isJnlpFile() { return _path.endsWith(_jnlpExtension); }
    public boolean isJarFile() { return _path.endsWith(_jarExtension); }

    /* Get JNLP version specific attributes */
    public String getName() { return _name; }
    public String getVersionId() { return _versionId; }
    public String[] getOSList()  { return _osList; }
    public String[] getArchList()  { return _archList; }
    public String[] getLocaleList()  { return _localeList; }
    public String   getReturnVersionId() { return _returnVersionId; }

    private String getMimeType(ServletContext context, String path) {
        String mimeType = context.getMimeType(path);
        if (mimeType != null) return mimeType;
        if (path.endsWith(_jnlpExtension)) return JNLP_MIME_TYPE;
        if (path.endsWith(_jarExtension)) return JAR_MIME_TYPE;
        return "application/unknown";
    }

    /** Print info about an entry */
    public String toString() {
        return "JnlpResource[WAR Path: " + _path +
            showEntry(" versionId=",_versionId) +
            showEntry(" name=", _name) +
            " lastModified=" + new Date(_lastModified) +
            showEntry(" osList=", _osList) +
            showEntry(" archList=", _archList) +
            showEntry(" localeList=", _localeList) + "]" +
            showEntry(" returnVersionId=", _returnVersionId) + "]";

    }

    private String showEntry(String msg, String value) {
        if (value == null) return "";
        return msg + value;
    }

    private String showEntry(String msg, String[] value) {
        if (value == null) return "";
        return msg + java.util.Arrays.asList(value).toString();
    }
}
