1/* 2 * Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package javax.tools; 27 28import java.io.Writer; 29import java.nio.charset.Charset; 30import java.util.Locale; 31import java.util.concurrent.Callable; 32import javax.annotation.processing.Processor; 33 34/** 35 * Interface to invoke Java™ programming language compilers from 36 * programs. 37 * 38 * <p>The compiler might generate diagnostics during compilation (for 39 * example, error messages). If a diagnostic listener is provided, 40 * the diagnostics will be supplied to the listener. If no listener 41 * is provided, the diagnostics will be formatted in an unspecified 42 * format and written to the default output, which is {@code 43 * System.err} unless otherwise specified. Even if a diagnostic 44 * listener is supplied, some diagnostics might not fit in a {@code 45 * Diagnostic} and will be written to the default output. 46 * 47 * <p>A compiler tool has an associated standard file manager, which 48 * is the file manager that is native to the tool (or built-in). The 49 * standard file manager can be obtained by calling {@linkplain 50 * #getStandardFileManager getStandardFileManager}. 51 * 52 * <p>A compiler tool must function with any file manager as long as 53 * any additional requirements as detailed in the methods below are 54 * met. If no file manager is provided, the compiler tool will use a 55 * standard file manager such as the one returned by {@linkplain 56 * #getStandardFileManager getStandardFileManager}. 57 * 58 * <p>An instance implementing this interface must conform to 59 * <cite>The Java™ Language Specification</cite> 60 * and generate class files conforming to 61 * <cite>The Java™ Virtual Machine Specification</cite>. 62 * The versions of these 63 * specifications are defined in the {@linkplain Tool} interface. 64 * 65 * Additionally, an instance of this interface supporting {@link 66 * javax.lang.model.SourceVersion#RELEASE_6 SourceVersion.RELEASE_6} 67 * or higher must also support {@linkplain javax.annotation.processing 68 * annotation processing}. 69 * 70 * <p>The compiler relies on two services: {@linkplain 71 * DiagnosticListener diagnostic listener} and {@linkplain 72 * JavaFileManager file manager}. Although most classes and 73 * interfaces in this package defines an API for compilers (and 74 * tools in general) the interfaces {@linkplain DiagnosticListener}, 75 * {@linkplain JavaFileManager}, {@linkplain FileObject}, and 76 * {@linkplain JavaFileObject} are not intended to be used in 77 * applications. Instead these interfaces are intended to be 78 * implemented and used to provide customized services for a 79 * compiler and thus defines an SPI for compilers. 80 * 81 * <p>There are a number of classes and interfaces in this package 82 * which are designed to ease the implementation of the SPI to 83 * customize the behavior of a compiler: 84 * 85 * <dl> 86 * <dt>{@link StandardJavaFileManager}</dt> 87 * <dd> 88 * 89 * Every compiler which implements this interface provides a 90 * standard file manager for operating on regular {@linkplain 91 * java.io.File files}. The StandardJavaFileManager interface 92 * defines additional methods for creating file objects from 93 * regular files. 94 * 95 * <p>The standard file manager serves two purposes: 96 * 97 * <ul> 98 * <li>basic building block for customizing how a compiler reads 99 * and writes files</li> 100 * <li>sharing between multiple compilation tasks</li> 101 * </ul> 102 * 103 * <p>Reusing a file manager can potentially reduce overhead of 104 * scanning the file system and reading jar files. Although there 105 * might be no reduction in overhead, a standard file manager must 106 * work with multiple sequential compilations making the following 107 * example a recommended coding pattern: 108 * 109 * <pre> 110 * File[] files1 = ... ; // input for first compilation task 111 * File[] files2 = ... ; // input for second compilation task 112 * 113 * JavaCompiler compiler = ToolProvider.getSystemJavaCompiler(); 114 * StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null); 115 * 116 * {@code Iterable<? extends JavaFileObject>} compilationUnits1 = 117 * fileManager.getJavaFileObjectsFromFiles({@linkplain java.util.Arrays#asList Arrays.asList}(files1)); 118 * compiler.getTask(null, fileManager, null, null, null, compilationUnits1).call(); 119 * 120 * {@code Iterable<? extends JavaFileObject>} compilationUnits2 = 121 * fileManager.getJavaFileObjects(files2); // use alternative method 122 * // reuse the same file manager to allow caching of jar files 123 * compiler.getTask(null, fileManager, null, null, null, compilationUnits2).call(); 124 * 125 * fileManager.close();</pre> 126 * 127 * </dd> 128 * 129 * <dt>{@link DiagnosticCollector}</dt> 130 * <dd> 131 * Used to collect diagnostics in a list, for example: 132 * <pre> 133 * {@code Iterable<? extends JavaFileObject>} compilationUnits = ...; 134 * JavaCompiler compiler = ToolProvider.getSystemJavaCompiler(); 135 * {@code DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<JavaFileObject>();} 136 * StandardJavaFileManager fileManager = compiler.getStandardFileManager(diagnostics, null, null); 137 * compiler.getTask(null, fileManager, diagnostics, null, null, compilationUnits).call(); 138 * 139 * for ({@code Diagnostic<? extends JavaFileObject>} diagnostic : diagnostics.getDiagnostics()) 140 * System.out.format("Error on line %d in %s%n", 141 * diagnostic.getLineNumber(), 142 * diagnostic.getSource().toUri()); 143 * 144 * fileManager.close();</pre> 145 * </dd> 146 * 147 * <dt> 148 * {@link ForwardingJavaFileManager}, {@link ForwardingFileObject}, and 149 * {@link ForwardingJavaFileObject} 150 * </dt> 151 * <dd> 152 * 153 * Subclassing is not available for overriding the behavior of a 154 * standard file manager as it is created by calling a method on a 155 * compiler, not by invoking a constructor. Instead forwarding 156 * (or delegation) should be used. These classes makes it easy to 157 * forward most calls to a given file manager or file object while 158 * allowing customizing behavior. For example, consider how to 159 * log all calls to {@linkplain JavaFileManager#flush}: 160 * 161 * <pre> 162 * final Logger logger = ...; 163 * {@code Iterable<? extends JavaFileObject>} compilationUnits = ...; 164 * JavaCompiler compiler = ToolProvider.getSystemJavaCompiler(); 165 * StandardJavaFileManager stdFileManager = compiler.getStandardFileManager(null, null, null); 166 * JavaFileManager fileManager = new ForwardingJavaFileManager(stdFileManager) { 167 * public void flush() throws IOException { 168 * logger.entering(StandardJavaFileManager.class.getName(), "flush"); 169 * super.flush(); 170 * logger.exiting(StandardJavaFileManager.class.getName(), "flush"); 171 * } 172 * }; 173 * compiler.getTask(null, fileManager, null, null, null, compilationUnits).call();</pre> 174 * </dd> 175 * 176 * <dt>{@link SimpleJavaFileObject}</dt> 177 * <dd> 178 * 179 * This class provides a basic file object implementation which 180 * can be used as building block for creating file objects. For 181 * example, here is how to define a file object which represent 182 * source code stored in a string: 183 * 184 * <pre> 185 * /** 186 * * A file object used to represent source coming from a string. 187 * {@code *}/ 188 * public class JavaSourceFromString extends SimpleJavaFileObject { 189 * /** 190 * * The source code of this "file". 191 * {@code *}/ 192 * final String code; 193 * 194 * /** 195 * * Constructs a new JavaSourceFromString. 196 * * {@code @}param name the name of the compilation unit represented by this file object 197 * * {@code @}param code the source code for the compilation unit represented by this file object 198 * {@code *}/ 199 * JavaSourceFromString(String name, String code) { 200 * super({@linkplain java.net.URI#create URI.create}("string:///" + name.replace('.','/') + Kind.SOURCE.extension), 201 * Kind.SOURCE); 202 * this.code = code; 203 * } 204 * 205 * {@code @}Override 206 * public CharSequence getCharContent(boolean ignoreEncodingErrors) { 207 * return code; 208 * } 209 * }</pre> 210 * </dd> 211 * </dl> 212 * 213 * @author Peter von der Ahé 214 * @author Jonathan Gibbons 215 * @see DiagnosticListener 216 * @see Diagnostic 217 * @see JavaFileManager 218 * @since 1.6 219 */ 220public interface JavaCompiler extends Tool, OptionChecker { 221 222 /** 223 * Creates a future for a compilation task with the given 224 * components and arguments. The compilation might not have 225 * completed as described in the CompilationTask interface. 226 * 227 * <p>If a file manager is provided, it must be able to handle all 228 * locations defined in {@link StandardLocation}. 229 * 230 * <p>Note that annotation processing can process both the 231 * compilation units of source code to be compiled, passed with 232 * the {@code compilationUnits} parameter, as well as class 233 * files, whose names are passed with the {@code classes} 234 * parameter. 235 * 236 * @param out a Writer for additional output from the compiler; 237 * use {@code System.err} if {@code null} 238 * @param fileManager a file manager; if {@code null} use the 239 * compiler's standard filemanager 240 * @param diagnosticListener a diagnostic listener; if {@code 241 * null} use the compiler's default method for reporting 242 * diagnostics 243 * @param options compiler options, {@code null} means no options 244 * @param classes names of classes to be processed by annotation 245 * processing, {@code null} means no class names 246 * @param compilationUnits the compilation units to compile, {@code 247 * null} means no compilation units 248 * @return an object representing the compilation 249 * @throws RuntimeException if an unrecoverable error 250 * occurred in a user supplied component. The 251 * {@linkplain Throwable#getCause() cause} will be the error in 252 * user code. 253 * @throws IllegalArgumentException if any of the options are invalid, 254 * or if any of the given compilation units are of other kind than 255 * {@linkplain JavaFileObject.Kind#SOURCE source} 256 */ 257 CompilationTask getTask(Writer out, 258 JavaFileManager fileManager, 259 DiagnosticListener<? super JavaFileObject> diagnosticListener, 260 Iterable<String> options, 261 Iterable<String> classes, 262 Iterable<? extends JavaFileObject> compilationUnits); 263 264 /** 265 * Returns a new instance of the standard file manager implementation 266 * for this tool. The file manager will use the given diagnostic 267 * listener for producing any non-fatal diagnostics. Fatal errors 268 * will be signaled with the appropriate exceptions. 269 * 270 * <p>The standard file manager will be automatically reopened if 271 * it is accessed after calls to {@code flush} or {@code close}. 272 * The standard file manager must be usable with other tools. 273 * 274 * @param diagnosticListener a diagnostic listener for non-fatal 275 * diagnostics; if {@code null} use the compiler's default method 276 * for reporting diagnostics 277 * @param locale the locale to apply when formatting diagnostics; 278 * {@code null} means the {@linkplain Locale#getDefault() default locale}. 279 * @param charset the character set used for decoding bytes; if 280 * {@code null} use the platform default 281 * @return the standard file manager 282 */ 283 StandardJavaFileManager getStandardFileManager( 284 DiagnosticListener<? super JavaFileObject> diagnosticListener, 285 Locale locale, 286 Charset charset); 287 288 /** 289 * Interface representing a future for a compilation task. The 290 * compilation task has not yet started. To start the task, call 291 * the {@linkplain #call call} method. 292 * 293 * <p>Before calling the call method, additional aspects of the 294 * task can be configured, for example, by calling the 295 * {@linkplain #setProcessors setProcessors} method. 296 */ 297 interface CompilationTask extends Callable<Boolean> { 298 /** 299 * Adds root modules to be taken into account during module 300 * resolution. 301 * Invalid module names may cause either 302 * {@code IllegalArgumentException} to be thrown, 303 * or diagnostics to be reported when the task is started. 304 * @param moduleNames the names of the root modules 305 * @throws IllegalArgumentException may be thrown for some 306 * invalid module names 307 * @throws IllegalStateException if the task has started 308 * @since 9 309 */ 310 void addModules(Iterable<String> moduleNames); 311 312 /** 313 * Sets processors (for annotation processing). This will 314 * bypass the normal discovery mechanism. 315 * 316 * @param processors processors (for annotation processing) 317 * @throws IllegalStateException if the task has started 318 */ 319 void setProcessors(Iterable<? extends Processor> processors); 320 321 /** 322 * Sets the locale to be applied when formatting diagnostics and 323 * other localized data. 324 * 325 * @param locale the locale to apply; {@code null} means apply no 326 * locale 327 * @throws IllegalStateException if the task has started 328 */ 329 void setLocale(Locale locale); 330 331 /** 332 * Performs this compilation task. The compilation may only 333 * be performed once. Subsequent calls to this method throw 334 * IllegalStateException. 335 * 336 * @return true if and only all the files compiled without errors; 337 * false otherwise 338 * 339 * @throws RuntimeException if an unrecoverable error occurred 340 * in a user-supplied component. The 341 * {@linkplain Throwable#getCause() cause} will be the error 342 * in user code. 343 * @throws IllegalStateException if called more than once 344 */ 345 @Override 346 Boolean call(); 347 } 348} 349