org.apidesign.html.kofx.LoadJSON Maven / Gradle / Ivy

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/**
 * HTML via Java(tm) Language Bindings
 * Copyright (C) 2013 Jaroslav Tulach 
 *
 * 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, version 2 of the License.
 *
 * 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. apidesign.org
 * designates this particular file as subject to the
 * "Classpath" exception as provided by apidesign.org
 * in the License file that accompanied this code.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. Look for COPYING file in the top folder.
 * If not, see http://wiki.apidesign.org/wiki/GPLwithClassPathException
 */
package org.apidesign.html.kofx;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PushbackInputStream;
import java.io.Reader;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Iterator;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.logging.Level;
import java.util.logging.Logger;
import javafx.application.Platform;
import javafx.scene.web.WebEngine;
import netscape.javascript.JSObject;
import org.apidesign.html.json.spi.JSONCall;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONTokener;
import org.openide.util.Exceptions;

/** This is an implementation package - just
 * include its JAR on classpath and use official {@link Context} API
 * to access the functionality.
 *
 * @author Jaroslav Tulach 
 */
final class LoadJSON implements Runnable {
    private static final Logger LOG = FXContext.LOG;
    private static final Executor REQ = Executors.newCachedThreadPool();

    private final JSONCall call;
    private final URL base;
    private Throwable error;
    private Object json;


    private LoadJSON(JSONCall call) {
        this.call = call;
        URL b;
        try {
            b = new URL(findBaseURL());
        } catch (MalformedURLException ex) {
            LOG.log(Level.SEVERE, "Can't find base url for " + call.composeURL("dummy"), ex);
            b = null;
        }
        this.base = b;
    }

    public static void loadJSON(JSONCall call) {
        REQ.execute(new LoadJSON((call)));
    }

    @Override
    public void run() {
        if (Platform.isFxApplicationThread()) {
            if (error != null) {
                call.notifyError(error);
            } else {
                call.notifySuccess(json);
            }
            return;
        }
        final String url;
        if (call.isJSONP()) {
            url = call.composeURL("dummy");
        } else {
            url = call.composeURL(null);
        }
        try {
            final URL u = new URL(base, url.replace(" ", "%20"));
            final PushbackInputStream is = new PushbackInputStream(u.openStream(), 1);
            boolean array = false;
            if (call.isJSONP()) {
                for (;;) {
                    int ch = is.read();
                    if (ch == -1) {
                        break;
                    }
                    if (ch == '[') {
                        is.unread(ch);
                        array = true;
                        break;
                    }
                    if (ch == '{') {
                        is.unread(ch);
                        break;
                    }
                }
            } else {
                int ch = is.read();
                array = ch == '[';
                is.unread(ch);
            }
            Reader r = new InputStreamReader(is, "UTF-8");

            JSONTokener tok = new JSONTokener(r);
            Object obj = array ? new JSONArray(tok) : new JSONObject(tok);
            json = convertToArray(obj);
        } catch (JSONException | IOException ex) {
            error = ex;
            LOG.log(Level.WARNING, "Cannot connect to " + url, ex);
        } finally {
            Platform.runLater(this);
        }
    }

    private static Object convertToArray(Object o) throws JSONException {
        if (o instanceof JSONArray) {
            JSONArray ja = (JSONArray)o;
            Object[] arr = new Object[ja.length()];
            for (int i = 0; i < arr.length; i++) {
                arr[i] = convertToArray(ja.get(i));
            }
            return arr;
        } else if (o instanceof JSONObject) {
            JSONObject obj = (JSONObject)o;
            Iterator it = obj.keys();
            while (it.hasNext()) {
                String key = (String)it.next();
                obj.put(key, convertToArray(obj.get(key)));
            }
            return obj;
        } else {
            return o;
        }
    }
    
    public static void extractJSON(Object jsonObject, String[] props, Object[] values) {
        if (jsonObject instanceof JSONObject) {
            JSONObject obj = (JSONObject)jsonObject;
            for (int i = 0; i < props.length; i++) {
                try {
                    values[i] = obj.has(props[i]) ? obj.get(props[i]) : null;
                } catch (JSONException ex) {
                    LoadJSON.LOG.log(Level.SEVERE, "Can't read " + props[i] + " from " + jsonObject, ex);
                }
            }
        }
        if (jsonObject instanceof JSObject) {
            JSObject obj = (JSObject)jsonObject;
            for (int i = 0; i < props.length; i++) {
                Object val = obj.getMember(props[i]);
                values[i] = isDefined(val) ? val : null;
            }
        }
    }
    
    public static Object parse(InputStream is) throws IOException {
        try {
            InputStreamReader r = new InputStreamReader(is, "UTF-8");
            JSONTokener t = new JSONTokener(r);
            return new JSONObject(t);
        } catch (JSONException ex) {
            throw new IOException(ex);
        }
    }
    
    private static String findBaseURL() {
        WebEngine eng = (WebEngine) System.getProperties().get("webEngine");
        return (String) eng.executeScript(
            "var h;"
            + "if (!!window && !!window.location && !!window.location.href)\n"
            + "  h = window.location.href;\n"
            + "else "
            + "  h = null;"
            + "h\n");
    }

    private static boolean isDefined(Object val) {
        return !"undefined".equals(val);
    }
}