Don't initialize @JavaScriptBody resources sooner than their methods are called.
2 * Back 2 Browser Bytecode Translator
3 * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, version 2 of the License.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. Look for COPYING file in the top folder.
16 * If not, see http://opensource.org/licenses/GPL-2.0.
18 package org.apidesign.vm4brwsr;
20 import java.io.IOException;
21 import java.io.InputStream;
23 /** Build your own virtual machine! Use methods in this class to generate
24 * a skeleton JVM in JavaScript that contains pre-compiled classes of your
25 * choice. The generated script defines one JavaScript method that can
26 * be used to bootstrap and load the virtual machine: <pre>
27 * var vm = bck2brwsr();
28 * var main = vm.loadClass('org.your.pkg.Main');
29 * main.invoke('main');
31 * In case one wants to initialize the virtual machine with ability to
32 * load classes lazily when needed, one can provide a loader function to
33 * when creating the virtual machine: <pre>
34 * var vm = bck2brwsr(function(resource) {
35 * return null; // byte[] for the resource
38 * In this scenario, when a request for an unknown class is made, the loader
39 * function is asked for its byte code and the system dynamically transforms
42 * Instead of a loader function, one can also provide a URL to a JAR file
43 * or a library JavaScript file generated with {@link #library(java.lang.String...)}
45 * The <code>bck2brwsr</code> system will do its best to download the file
46 * and provide loader function for it automatically. In order to use
47 * the JAR file <code>emul.zip</code> module needs to be available in the system.
49 * One can provide as many loader functions and URL references as necessary.
50 * Then the initialization code would look like:<pre>
51 * var vm = bck2brwsr(url1, url2, fnctn1, url3, functn2);
53 * The provided URLs and loader functions will be consulted one by one.
55 * The initialization of the <b>Bck2Brwsr</b> is done asynchronously since
56 * version 0.9. E.g. call to <pre>
57 * var vm = bck2brwsr('myapp.js');
58 * var main = vm.loadClass('org.your.pkg.Main');
59 * main.invoke('main');
61 * returns immediately and the call to the static main method will happen
62 * once the virtual machine is initialized and the class available.
64 * @author Jaroslav Tulach <jtulach@netbeans.org>
66 public final class Bck2Brwsr {
67 private final ObfuscationLevel level;
68 private final StringArray exported;
69 private final StringArray classes;
70 private final StringArray resources;
71 private final Resources res;
72 private final Boolean extension;
73 private final StringArray classpath;
76 ObfuscationLevel level,
77 StringArray exported, StringArray classes, StringArray resources,
79 Boolean extension, StringArray classpath
82 this.exported = exported;
83 this.classes = classes;
84 this.resources = resources;
86 this.extension = extension;
87 this.classpath = classpath;
90 /** Helper method to generate virtual machine from bytes served by a <code>resources</code>
93 * @param out the output to write the generated JavaScript to
94 * @param resources provider of class files to use
95 * @param classes additional classes to include in the generated script
96 * @throws IOException I/O exception can be thrown when something goes wrong
98 public static void generate(Appendable out, Resources resources, String... classes) throws IOException {
99 newCompiler().resources(resources).addRootClasses(classes).generate(out);
102 /** Helper method to generate virtual machine from bytes served by a class loader.
104 * @param out the output to write the generated JavaScript to
105 * @param loader class loader to load needed classes from
106 * @param classes additional classes to include in the generated script
107 * @throws IOException I/O exception can be thrown when something goes wrong
109 public static void generate(Appendable out, ClassLoader loader, String... classes) throws IOException {
110 newCompiler().resources(loader).addRootClasses(classes).generate(out);
113 /** Creates new instance of Bck2Brwsr compiler which is ready to generate
114 * empty Bck2Brwsr virtual machine. The instance can be further
115 * configured by calling chain of methods. For example:
117 * {@link #createCompiler()}.{@link #resources(org.apidesign.vm4brwsr.Bck2Brwsr.Resources) resources(loader)}.{@link #addRootClasses(java.lang.String[]) addRootClasses("your/Clazz")}.{@link #generate(java.lang.Appendable) generate(out)};
120 * @return new instance of the Bck2Brwsr compiler
123 public static Bck2Brwsr newCompiler() {
124 return new Bck2Brwsr(
125 ObfuscationLevel.NONE,
126 new StringArray(), new StringArray(), new StringArray(),
131 /** Adds exported classes or packages. If the string ends
132 * with slash, it is considered a name of package. If it does not,
133 * it is a name of a class (without <code>.class</code> suffix).
134 * The exported classes are prevented from being obfuscated.
135 * All public classes in exported packages are prevented from
136 * being obfuscated. By listing the packages or classes in this
137 * method, these classes are not guaranteed to be included in
138 * the generated script. Use {@link #addClasses} to include
141 * @param exported names of classes and packages to treat as exported
142 * @return new instances of the Bck2Brwsr compiler which inherits
143 * all values from <code>this</code> except list of exported classes
145 public Bck2Brwsr addExported(String... exported) {
146 return new Bck2Brwsr(
147 level, this.exported.addAndNew(exported),
148 classes, resources, res, extension, classpath
152 /** Adds additional classes
153 * to the list of those that should be included in the generated
155 * These classes are guaranteed to be available in the
156 * generated virtual machine code accessible using their fully
157 * qualified name. This brings the same behavior as if the
158 * classes were added by {@link #addClasses(java.lang.String...) } and
159 * exported via {@link #addExported(java.lang.String...)}.
161 * @param classes the classes to add to the compilation
162 * @return new instance of the Bck2Brwsr compiler which inherits
163 * all values from <code>this</code>
165 public Bck2Brwsr addRootClasses(String... classes) {
166 if (classes.length == 0) {
169 return addExported(classes).addClasses(classes);
172 /** Adds additional classes
173 * to the list of those that should be included in the generated
174 * JavaScript file. These classes are guaranteed to be present,
175 * but they may not be accessible through their fully qualified
178 * @param classes the classes to add to the compilation
179 * @return new instance of the Bck2Brwsr compiler which inherits
180 * all values from <code>this</code>
183 public Bck2Brwsr addClasses(String... classes) {
184 if (classes.length == 0) {
187 return new Bck2Brwsr(level, exported,
188 this.classes.addAndNew(classes), resources, res,
189 extension, classpath);
193 /** These resources should be made available in the compiled file in
194 * binary form. These resources can then be loaded
195 * by {@link ClassLoader#getResource(java.lang.String)} and similar
198 * @param resources names of the resources to be loaded by {@link Resources#get(java.lang.String)}
199 * @return new instance of the Bck2Brwsr compiler which inherits
200 * all values from <code>this</code> just adds few more resource names
204 public Bck2Brwsr addResources(String... resources) {
205 if (resources.length == 0) {
208 return new Bck2Brwsr(level, exported, this.classes,
209 this.resources.addAndNew(resources), res, extension, classpath
214 /** Changes the obfuscation level for the compiler by creating new instance
215 * which inherits all values from <code>this</code> and adjust the level
218 * @param level the new level of obfuscation
219 * @return new instance of the compiler with changed level of obfuscation
222 public Bck2Brwsr obfuscation(ObfuscationLevel level) {
223 return new Bck2Brwsr(level, exported, classes, resources, res, extension, classpath);
226 /** A way to change the provider of additional resources (classes) for the
229 * @param res the implementation of resources provider
230 * @return new instance of the compiler with all values remaining the same, just
231 * with different resources provider
234 public Bck2Brwsr resources(Resources res) {
235 return new Bck2Brwsr(
236 level, exported, classes, resources,
237 res, extension, classpath
241 /** Should one generate a library? By default the system generates
242 * all transitive classes needed by the the transitive closure of
243 * {@link #addRootClasses(java.lang.String...)} and {@link #addClasses(java.lang.String...)}.
244 * By turning on the library mode, only classes explicitly listed
245 * will be included in the archive. The others will be referenced
248 * A library archive may specify its <em>classpath</em> - e.g. link to
249 * other libraries that should also be included in the application.
250 * One can specify the list of libraries as vararg to this method.
251 * These are relative URL with respect to location of this library.
252 * The runtime system then prefers seek for ".js" suffix of the library
253 * and only then seeks for the classical ".jar" path.
255 * @param classpath the array of JARs that are referenced by this library -
256 * by default gets turned into
257 * @return new instance of the compiler with library flag changed
260 public Bck2Brwsr library(String... classpath) {
261 return new Bck2Brwsr(
262 level, exported, classes,
263 resources, res, true,
264 StringArray.asList(classpath)
268 /** Turns on the standalone mode. E.g. acts like {@link #library(boolean) library(false)},
269 * but also allows to specify whether the <em>Bck2Brwsr VM</em> should
270 * be included at all. If not, only the skeleton of the launcher is
271 * generated without any additional VM classes referenced.
273 * @param includeVM should the VM be compiled in, or left out
274 * @return new instance of the compiler with standalone mode on
277 public Bck2Brwsr standalone(boolean includeVM) {
278 return new Bck2Brwsr(
279 level, exported, classes, resources,
280 res, includeVM ? false : null, null
284 /** A way to change the provider of additional resources (classes) for the
285 * compiler by specifying classloader to use for loading them.
287 * @param loader class loader to load the resources from
288 * @return new instance of the compiler with all values being the same, just
289 * different resources provider
292 public Bck2Brwsr resources(final ClassLoader loader) {
293 return resources(loader, false);
296 /** A way to change the provider of additional resources (classes) for the
297 * compiler by specifying classloader to use for loading them.
299 * @param loader class loader to load the resources from
300 * @param ignoreBootClassPath <code>true</code> if classes loaded
301 * from <code>rt.jar</code>
302 * @return new instance of the compiler with all values being the same, just
303 * different resources provider
306 public Bck2Brwsr resources(final ClassLoader loader, boolean ignoreBootClassPath) {
307 return resources(new LdrRsrcs(loader, ignoreBootClassPath));
310 /** Generates virtual machine based on previous configuration of the
313 * @param out the output to write the generated JavaScript to
316 public void generate(Appendable out) throws IOException {
317 if (level != ObfuscationLevel.NONE) {
319 ClosureWrapper.produceTo(out, level, this);
321 } catch (IOException ex) {
323 } catch (Throwable ex) {
324 out.append("/* Failed to obfuscate: " + ex.getMessage()
329 VM.compile(out, this);
336 Resources getResources() {
337 return res != null ? res : new LdrRsrcs(Bck2Brwsr.class.getClassLoader(), false);
340 StringArray allResources() {
344 StringArray classes() {
348 StringArray exported() {
352 boolean isExtension() {
353 return Boolean.TRUE.equals(extension);
356 boolean includeVM() {
357 return extension != null;
360 StringArray classpath() {
364 /** Provider of resources (classes and other files). The
365 * {@link #generate(java.lang.Appendable, org.apidesign.vm4brwsr.Bck2Brwsr.Resources, java.lang.String[])
366 * generator method} will call back here for all classes needed during
367 * translation to JavaScript.
369 public interface Resources {
370 /** Loads given resource (class or other file like image). The
371 * resource name to load bytes for the {@link String} class
372 * would be <code>"java/lang/String.class"</code>.
374 * @param resource path to resource to load
375 * @return the input stream for the resource
376 * @throws IOException can be thrown if the loading fails on some error
377 * or the file cannot be found
379 public InputStream get(String resource) throws IOException;