The static calculator demo needs to reference just a single application .js file from its main HTML page. The rest is loaded based on classpath attribute.
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.main__V_3Ljava_lang_String_2(null);
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 * The <code>bck2brwsr</code> system will do its best to download the file
44 * and provide loader function for it automatically.
46 * One can provide as many loader functions and JAR URL references as necessary.
47 * Then the initialization code would look like:<pre>
48 * var vm = bck2brwsr(url1, url2, fnctn1, url3, functn2);
50 * The provided URLs and loader functions will be consulted one by one.
52 * @author Jaroslav Tulach <jtulach@netbeans.org>
54 public final class Bck2Brwsr {
55 private final ObfuscationLevel level;
56 private final StringArray exported;
57 private final StringArray classes;
58 private final StringArray resources;
59 private final Resources res;
60 private final Boolean extension;
61 private final StringArray classpath;
64 ObfuscationLevel level,
65 StringArray exported, StringArray classes, StringArray resources,
67 Boolean extension, StringArray classpath
70 this.exported = exported;
71 this.classes = classes;
72 this.resources = resources;
74 this.extension = extension;
75 this.classpath = classpath;
78 /** Helper method to generate virtual machine from bytes served by a <code>resources</code>
81 * @param out the output to write the generated JavaScript to
82 * @param resources provider of class files to use
83 * @param classes additional classes to include in the generated script
84 * @throws IOException I/O exception can be thrown when something goes wrong
86 public static void generate(Appendable out, Resources resources, String... classes) throws IOException {
87 newCompiler().resources(resources).addRootClasses(classes).generate(out);
90 /** Helper method to generate virtual machine from bytes served by a class loader.
92 * @param out the output to write the generated JavaScript to
93 * @param loader class loader to load needed classes from
94 * @param classes additional classes to include in the generated script
95 * @throws IOException I/O exception can be thrown when something goes wrong
97 public static void generate(Appendable out, ClassLoader loader, String... classes) throws IOException {
98 newCompiler().resources(loader).addRootClasses(classes).generate(out);
101 /** Creates new instance of Bck2Brwsr compiler which is ready to generate
102 * empty Bck2Brwsr virtual machine. The instance can be further
103 * configured by calling chain of methods. For example:
105 * {@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)};
108 * @return new instance of the Bck2Brwsr compiler
111 public static Bck2Brwsr newCompiler() {
112 return new Bck2Brwsr(
113 ObfuscationLevel.NONE,
114 new StringArray(), new StringArray(), new StringArray(),
119 /** Adds exported classes or packages. If the string ends
120 * with slash, it is considered a name of package. If it does not,
121 * it is a name of a class (without <code>.class</code> suffix).
122 * The exported classes are prevented from being obfuscated.
123 * All public classes in exported packages are prevented from
124 * being obfuscated. By listing the packages or classes in this
125 * method, these classes are not guaranteed to be included in
126 * the generated script. Use {@link #addClasses} to include
129 * @param exported names of classes and packages to treat as exported
130 * @return new instances of the Bck2Brwsr compiler which inherits
131 * all values from <code>this</code> except list of exported classes
133 public Bck2Brwsr addExported(String... exported) {
134 return new Bck2Brwsr(
135 level, this.exported.addAndNew(exported),
136 classes, resources, res, extension, classpath
140 /** Adds additional classes
141 * to the list of those that should be included in the generated
143 * These classes are guaranteed to be available in the
144 * generated virtual machine code accessible using their fully
145 * qualified name. This brings the same behavior as if the
146 * classes were added by {@link #addClasses(java.lang.String...) } and
147 * exported via {@link #addExported(java.lang.String...)}.
149 * @param classes the classes to add to the compilation
150 * @return new instance of the Bck2Brwsr compiler which inherits
151 * all values from <code>this</code>
153 public Bck2Brwsr addRootClasses(String... classes) {
154 if (classes.length == 0) {
157 return addExported(classes).addClasses(classes);
160 /** Adds additional classes
161 * to the list of those that should be included in the generated
162 * JavaScript file. These classes are guaranteed to be present,
163 * but they may not be accessible through their fully qualified
166 * @param classes the classes to add to the compilation
167 * @return new instance of the Bck2Brwsr compiler which inherits
168 * all values from <code>this</code>
171 public Bck2Brwsr addClasses(String... classes) {
172 if (classes.length == 0) {
175 return new Bck2Brwsr(level, exported,
176 this.classes.addAndNew(classes), resources, res,
177 extension, classpath);
181 /** These resources should be made available in the compiled file in
182 * binary form. These resources can then be loaded
183 * by {@link ClassLoader#getResource(java.lang.String)} and similar
186 * @param resources names of the resources to be loaded by {@link Resources#get(java.lang.String)}
187 * @return new instance of the Bck2Brwsr compiler which inherits
188 * all values from <code>this</code> just adds few more resource names
192 public Bck2Brwsr addResources(String... resources) {
193 if (resources.length == 0) {
196 return new Bck2Brwsr(level, exported, this.classes,
197 this.resources.addAndNew(resources), res, extension, classpath
202 /** Changes the obfuscation level for the compiler by creating new instance
203 * which inherits all values from <code>this</code> and adjust the level
206 * @param level the new level of obfuscation
207 * @return new instance of the compiler with changed level of obfuscation
210 public Bck2Brwsr obfuscation(ObfuscationLevel level) {
211 return new Bck2Brwsr(level, exported, classes, resources, res, extension, classpath);
214 /** A way to change the provider of additional resources (classes) for the
217 * @param res the implementation of resources provider
218 * @return new instance of the compiler with all values remaining the same, just
219 * with different resources provider
222 public Bck2Brwsr resources(Resources res) {
223 return new Bck2Brwsr(
224 level, exported, classes, resources,
225 res, extension, classpath
229 /** Should one generate a library? By default the system generates
230 * all transitive classes needed by the the transitive closure of
231 * {@link #addRootClasses(java.lang.String...)} and {@link #addClasses(java.lang.String...)}.
232 * By turning on the library mode, only classes explicitly listed
233 * will be included in the archive. The others will be referenced
236 * A library archive may specify its <em>classpath</em> - e.g. link to
237 * other libraries that should also be included in the application.
238 * One can specify the list of libraries as vararg to this method.
239 * These are relative URL with respect to location of this library.
240 * The runtime system then prefers seek for ".js" suffix of the library
241 * and only then seeks for the classical ".jar" path.
243 * @param classpath the array of JARs that are referenced by this library -
244 * by default gets turned into
245 * @return new instance of the compiler with library flag changed
248 public Bck2Brwsr library(String... classpath) {
249 return new Bck2Brwsr(
250 level, exported, classes,
251 resources, res, true,
252 StringArray.asList(classpath)
256 /** Turns on the standalone mode. E.g. acts like {@link #library(boolean) library(false)},
257 * but also allows to specify whether the <em>Bck2Brwsr VM</em> should
258 * be included at all. If not, only the skeleton of the launcher is
259 * generated without any additional VM classes referenced.
261 * @param includeVM should the VM be compiled in, or left out
262 * @return new instance of the compiler with standalone mode on
265 public Bck2Brwsr standalone(boolean includeVM) {
266 return new Bck2Brwsr(
267 level, exported, classes, resources,
268 res, includeVM ? false : null, null
272 /** A way to change the provider of additional resources (classes) for the
273 * compiler by specifying classloader to use for loading them.
275 * @param loader class loader to load the resources from
276 * @return new instance of the compiler with all values being the same, just
277 * different resources provider
280 public Bck2Brwsr resources(final ClassLoader loader) {
281 return resources(loader, false);
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 * @param ignoreBootClassPath <code>true</code> if classes loaded
289 * from <code>rt.jar</code>
290 * @return new instance of the compiler with all values being the same, just
291 * different resources provider
294 public Bck2Brwsr resources(final ClassLoader loader, boolean ignoreBootClassPath) {
295 return resources(new LdrRsrcs(loader, ignoreBootClassPath));
298 /** Generates virtual machine based on previous configuration of the
301 * @param out the output to write the generated JavaScript to
304 public void generate(Appendable out) throws IOException {
305 if (level != ObfuscationLevel.NONE) {
307 ClosureWrapper.produceTo(out, level, this);
309 } catch (IOException ex) {
311 } catch (Throwable ex) {
312 out.append("/* Failed to obfuscate: " + ex.getMessage()
317 VM.compile(out, this);
324 Resources getResources() {
325 return res != null ? res : new LdrRsrcs(Bck2Brwsr.class.getClassLoader(), false);
328 StringArray allResources() {
332 StringArray classes() {
336 StringArray exported() {
340 boolean isExtension() {
341 return Boolean.TRUE.equals(extension);
344 boolean includeVM() {
345 return extension != null;
348 StringArray classpath() {
352 /** Provider of resources (classes and other files). The
353 * {@link #generate(java.lang.Appendable, org.apidesign.vm4brwsr.Bck2Brwsr.Resources, java.lang.String[])
354 * generator method} will call back here for all classes needed during
355 * translation to JavaScript.
357 public interface Resources {
358 /** Loads given resource (class or other file like image). The
359 * resource name to load bytes for the {@link String} class
360 * would be <code>"java/lang/String.class"</code>.
362 * @param resource path to resource to load
363 * @return the input stream for the resource
364 * @throws IOException can be thrown if the loading fails on some error
365 * or the file cannot be found
367 public InputStream get(String resource) throws IOException;