Different meaning of root vs. added classes. Ability to explicitly enumerate classes that should be exported and available with fully qualified name.
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 import org.apidesign.bck2brwsr.core.Exported;
25 /** Build your own virtual machine! Use methods in this class to generate
26 * a skeleton JVM in JavaScript that contains pre-compiled classes of your
27 * choice. The generated script defines one JavaScript method that can
28 * be used to bootstrap and load the virtual machine: <pre>
29 * var vm = bck2brwsr();
30 * var main = vm.loadClass('org.your.pkg.Main');
31 * main.main__V_3Ljava_lang_String_2(null);
33 * In case one wants to initialize the virtual machine with ability to
34 * load classes lazily when needed, one can provide a loader function to
35 * when creating the virtual machine: <pre>
36 * var vm = bck2brwsr(function(resource) {
37 * return null; // byte[] for the resource
40 * In this scenario, when a request for an unknown class is made, the loader
41 * function is asked for its byte code and the system dynamically transforms
44 * Instead of a loader function, one can also provide a URL to a JAR file.
45 * The <code>bck2brwsr</code> system will do its best to download the file
46 * and provide loader function for it automatically.
48 * One can provide as many loader functions and JAR URL references as necessary.
49 * Then the initialization code would look like:<pre>
50 * var vm = bck2brwsr(url1, url2, fnctn1, url3, functn2);
52 * The provided URLs and loader functions will be consulted one by one.
54 * @author Jaroslav Tulach <jtulach@netbeans.org>
56 public final class Bck2Brwsr {
57 private final ObfuscationLevel level;
58 private final StringArray rootcls;
59 private final StringArray classes;
60 private final Resources res;
61 private final boolean extension;
63 private Bck2Brwsr(ObfuscationLevel level, StringArray rootcls, StringArray classes, Resources resources, boolean extension) {
65 this.rootcls = rootcls;
66 this.classes = classes;
68 this.extension = extension;
71 /** Helper method to generate virtual machine from bytes served by a <code>resources</code>
74 * @param out the output to write the generated JavaScript to
75 * @param resources provider of class files to use
76 * @param classes additional classes to include in the generated script
77 * @throws IOException I/O exception can be thrown when something goes wrong
79 public static void generate(Appendable out, Resources resources, String... classes) throws IOException {
80 newCompiler().resources(resources).addRootClasses(classes).generate(out);
83 /** Helper method to generate virtual machine from bytes served by a class loader.
85 * @param out the output to write the generated JavaScript to
86 * @param loader class loader to load needed classes from
87 * @param classes additional classes to include in the generated script
88 * @throws IOException I/O exception can be thrown when something goes wrong
90 public static void generate(Appendable out, ClassLoader loader, String... classes) throws IOException {
91 newCompiler().resources(loader).addRootClasses(classes).generate(out);
94 /** Creates new instance of Bck2Brwsr compiler which is ready to generate
95 * empty Bck2Brwsr virtual machine. The instance can be further
96 * configured by calling chain of methods. For example:
98 * {@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)};
101 * @return new instance of the Bck2Brwsr compiler
104 public static Bck2Brwsr newCompiler() {
105 return new Bck2Brwsr(ObfuscationLevel.NONE, new StringArray(), new StringArray(), null, false);
108 /** Adds additional classes
109 * to the list of those that should be included in the generated
111 * These classes are guaranteed to be available in the
112 * generated virtual machine code accessible using their fully
113 * qualified name. This brings the same behavior as if the
114 * classes were added by {@link #addClasses(java.lang.String...) } and
115 * were annotated with {@link Exported} annotation.
117 * @param classes the classes to add to the compilation
118 * @return new instance of the Bck2Brwsr compiler which inherits
119 * all values from <code>this</code>
121 public Bck2Brwsr addRootClasses(String... classes) {
122 if (classes.length == 0) {
125 return new Bck2Brwsr(level, rootcls.addAndNew(classes), this.classes, res,
130 /** Adds additional classes
131 * to the list of those that should be included in the generated
132 * JavaScript file. These classes are guaranteed to be present,
133 * but they may not be accessible through their fully qualified
136 * @param classes the classes to add to the compilation
137 * @return new instance of the Bck2Brwsr compiler which inherits
138 * all values from <code>this</code>
141 public Bck2Brwsr addClasses(String... classes) {
142 if (classes.length == 0) {
145 return new Bck2Brwsr(level, rootcls, this.classes.addAndNew(classes), res,
150 /** Changes the obfuscation level for the compiler by creating new instance
151 * which inherits all values from <code>this</code> and adjust the level
154 * @param level the new level of obfuscation
155 * @return new instance of the compiler with changed level of obfuscation
158 public Bck2Brwsr obfuscation(ObfuscationLevel level) {
159 return new Bck2Brwsr(level, rootcls, classes, res, extension);
162 /** A way to change the provider of additional resources (classes) for the
165 * @param res the implementation of resources provider
166 * @return new instance of the compiler with all values remaining the same, just
167 * with different resources provider
170 public Bck2Brwsr resources(Resources res) {
171 return new Bck2Brwsr(level, rootcls, classes, res, extension);
174 /** Should one generate a library? By default the system generates
175 * all transitive classes needed by the the transitive closure of
176 * {@link #addRootClasses(java.lang.String...)} and {@link #addClasses(java.lang.String...)}.
177 * By turning on the library mode, only classes explicitly listed
178 * will be included in the archive. The others will be referenced
181 * @param library turn on the library mode?
182 * @return new instance of the compiler with library flag changed
185 public Bck2Brwsr library(boolean library) {
186 return new Bck2Brwsr(level, rootcls, classes, res, library);
189 /** A way to change the provider of additional resources (classes) for the
190 * compiler by specifying classloader to use for loading them.
192 * @param loader class loader to load the resources from
193 * @return new instance of the compiler with all values being the same, just
194 * different resources provider
197 public Bck2Brwsr resources(final ClassLoader loader) {
198 return resources(new LdrRsrcs(loader));
201 /** Generates virtual machine based on previous configuration of the
204 * @param out the output to write the generated JavaScript to
207 public void generate(Appendable out) throws IOException {
208 Resources r = res != null ? res : new LdrRsrcs(Bck2Brwsr.class.getClassLoader());
209 if (level != ObfuscationLevel.NONE) {
211 ClosureWrapper.produceTo(out, level, r, rootcls, classes, extension);
213 } catch (IOException ex) {
215 } catch (Throwable ex) {
216 out.append("/* Failed to obfuscate: " + ex.getMessage()
221 VM.compile(out, r, rootcls, classes, extension);
224 /** Provider of resources (classes and other files). The
225 * {@link #generate(java.lang.Appendable, org.apidesign.vm4brwsr.Bck2Brwsr.Resources, java.lang.String[])
226 * generator method} will call back here for all classes needed during
227 * translation to JavaScript.
229 public interface Resources {
230 /** Loads given resource (class or other file like image). The
231 * resource name to load bytes for the {@link String} class
232 * would be <code>"java/lang/String.class"</code>.
234 * @param resource path to resource to load
235 * @return the input stream for the resource
236 * @throws IOException can be thrown if the loading fails on some error
237 * or the file cannot be found
239 public InputStream get(String resource) throws IOException;