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
26 package java.lang;
27
28 import java.util.Objects;
29
30 /**
31 * An element in a stack trace, as returned by {@link
32 * Throwable#getStackTrace()}. Each element represents a single stack frame.
33 * All stack frames except for the one at the top of the stack represent
34 * a method invocation. The frame at the top of the stack represents the
35 * execution point at which the stack trace was generated. Typically,
36 * this is the point at which the throwable corresponding to the stack trace
37 * was created.
38 *
39 * @since 1.4
40 * @author Josh Bloch
41 */
42 public final class StackTraceElement implements java.io.Serializable {
43 // Normally initialized by VM (public constructor added in 1.5)
44 private String moduleName;
45 private String moduleVersion;
46 private String declaringClass;
47 private String methodName;
48 private String fileName;
49 private int lineNumber;
50
51 /**
52 * Creates a stack trace element representing the specified execution
53 * point. The {@link #getModuleName module name} and {@link
54 * #getModuleVersion module version} of the stack trace element will
55 * be {@code null}.
56 *
57 * @param declaringClass the fully qualified name of the class containing
58 * the execution point represented by the stack trace element
59 * @param methodName the name of the method containing the execution point
60 * represented by the stack trace element
61 * @param fileName the name of the file containing the execution point
62 * represented by the stack trace element, or {@code null} if
63 * this information is unavailable
64 * @param lineNumber the line number of the source line containing the
65 * execution point represented by this stack trace element, or
66 * a negative number if this information is unavailable. A value
67 * of -2 indicates that the method containing the execution point
68 * is a native method
69 * @throws NullPointerException if {@code declaringClass} or
70 * {@code methodName} is null
71 * @since 1.5
72 */
73 public StackTraceElement(String declaringClass, String methodName,
74 String fileName, int lineNumber) {
75 this(null, null, declaringClass, methodName, fileName, lineNumber);
76 }
77
78 /**
79 * Creates a stack trace element representing the specified execution
80 * point.
81 *
82 * @param moduleName the module name if the class containing the
83 * execution point represented by the stack trace is in a named
84 * module; can be {@code null}
85 * @param moduleVersion the module version if the class containing the
86 * execution point represented by the stack trace is in a named
87 * module that has a version; can be {@code null}
88 * @param declaringClass the fully qualified name of the class containing
89 * the execution point represented by the stack trace element
90 * @param methodName the name of the method containing the execution point
91 * represented by the stack trace element
92 * @param fileName the name of the file containing the execution point
93 * represented by the stack trace element, or {@code null} if
94 * this information is unavailable
95 * @param lineNumber the line number of the source line containing the
96 * execution point represented by this stack trace element, or
97 * a negative number if this information is unavailable. A value
98 * of -2 indicates that the method containing the execution point
99 * is a native method
100 * @throws NullPointerException if {@code declaringClass} is {@code null}
101 * or {@code methodName} is {@code null}
102 * @since 9
103 */
104 public StackTraceElement(String moduleName, String moduleVersion,
105 String declaringClass, String methodName,
106 String fileName, int lineNumber) {
107 this.moduleName = moduleName;
108 this.moduleVersion = moduleVersion;
109 this.declaringClass = Objects.requireNonNull(declaringClass, "Declaring class is null");
110 this.methodName = Objects.requireNonNull(methodName, "Method name is null");
111 this.fileName = fileName;
112 this.lineNumber = lineNumber;
113 }
114
115
116 /**
117 * Creates an empty stack frame element to be filled in by Throwable.
118 */
119 StackTraceElement() { }
120
121 /**
122 * Returns the name of the source file containing the execution point
123 * represented by this stack trace element. Generally, this corresponds
124 * to the {@code SourceFile} attribute of the relevant {@code class}
125 * file (as per <i>The Java Virtual Machine Specification</i>, Section
126 * 4.7.7). In some systems, the name may refer to some source code unit
127 * other than a file, such as an entry in source repository.
128 *
129 * @return the name of the file containing the execution point
130 * represented by this stack trace element, or {@code null} if
131 * this information is unavailable.
132 */
133 public String getFileName() {
134 return fileName;
135 }
136
137 /**
138 * Returns the line number of the source line containing the execution
139 * point represented by this stack trace element. Generally, this is
161 */
162 public String getModuleName() {
163 return moduleName;
164 }
165
166 /**
167 * Returns the module version of the module containing the execution point
168 * represented by this stack trace element.
169 *
170 * @return the module version of the {@code Module} containing the execution
171 * point represented by this stack trace element; {@code null}
172 * if the module version is not available.
173 * @since 9
174 * @see java.lang.module.ModuleDescriptor.Version
175 */
176 public String getModuleVersion() {
177 return moduleVersion;
178 }
179
180 /**
181 * Returns the fully qualified name of the class containing the
182 * execution point represented by this stack trace element.
183 *
184 * @return the fully qualified name of the {@code Class} containing
185 * the execution point represented by this stack trace element.
186 */
187 public String getClassName() {
188 return declaringClass;
189 }
190
191 /**
192 * Returns the name of the method containing the execution point
193 * represented by this stack trace element. If the execution point is
194 * contained in an instance or class initializer, this method will return
195 * the appropriate <i>special method name</i>, {@code <init>} or
196 * {@code <clinit>}, as per Section 3.9 of <i>The Java Virtual
197 * Machine Specification</i>.
198 *
199 * @return the name of the method containing the execution point
200 * represented by this stack trace element.
203 return methodName;
204 }
205
206 /**
207 * Returns true if the method containing the execution point
208 * represented by this stack trace element is a native method.
209 *
210 * @return {@code true} if the method containing the execution point
211 * represented by this stack trace element is a native method.
212 */
213 public boolean isNativeMethod() {
214 return lineNumber == -2;
215 }
216
217 /**
218 * Returns a string representation of this stack trace element. The
219 * format of this string depends on the implementation, but the following
220 * examples may be regarded as typical:
221 * <ul>
222 * <li>
223 * {@code "MyClass.mash(my.module@9.0/MyClass.java:101)"} - Here,
224 * {@code "MyClass"} is the <i>fully-qualified name</i> of the class
225 * containing the execution point represented by this stack trace element,
226 * {@code "mash"} is the name of the method containing the execution
227 * point, {@code "my.module"} is the module name, {@code "9.0"} is the
228 * module version, and {@code "101"} is the line number of the source
229 * line containing the execution point.
230 * <li>
231 * {@code "MyClass.mash(my.module@9.0/MyClass.java)"} - As above, but the
232 * line number is unavailable.
233 * <li>
234 * {@code "MyClass.mash(my.module@9.0/Unknown Source)"} - As above, but
235 * neither the file name nor the line number are available.
236 * <li>
237 * {@code "MyClass.mash(my.module@9.0/Native Method)"} - As above, but
238 * neither the file name nor the line number are available, and the
239 * method containing the execution point is known to be a native method.
240 * </ul>
241 * If the execution point is not in a named module, {@code "my.module@9.0/"}
242 * will be omitted from the above.
243 *
244 * @see Throwable#printStackTrace()
245 */
246 public String toString() {
247 String mid = "";
248 if (moduleName != null) {
249 mid = moduleName;
250 if (moduleVersion != null)
251 mid += "@" + moduleVersion;
252 mid += "/";
253 }
254 return getClassName() + "." + methodName + "(" + mid +
255 (isNativeMethod() ? "Native Method)" :
256 (fileName != null && lineNumber >= 0 ?
257 fileName + ":" + lineNumber + ")" :
258 (fileName != null ? ""+fileName+")" : "Unknown Source)")));
259 }
260
261 /**
262 * Returns true if the specified object is another
263 * {@code StackTraceElement} instance representing the same execution
264 * point as this instance. Two stack trace elements {@code a} and
265 * {@code b} are equal if and only if:
266 * <pre>{@code
267 * equals(a.getFileName(), b.getFileName()) &&
268 * a.getLineNumber() == b.getLineNumber()) &&
269 * equals(a.getModuleName(), b.getModuleName()) &&
270 * equals(a.getModuleVersion(), b.getModuleVersion()) &&
271 * equals(a.getClassName(), b.getClassName()) &&
272 * equals(a.getMethodName(), b.getMethodName())
273 * }</pre>
274 * where {@code equals} has the semantics of {@link
275 * java.util.Objects#equals(Object, Object) Objects.equals}.
276 *
277 * @param obj the object to be compared with this stack trace element.
278 * @return true if the specified object is another
279 * {@code StackTraceElement} instance representing the same
280 * execution point as this instance.
281 */
282 public boolean equals(Object obj) {
283 if (obj==this)
284 return true;
285 if (!(obj instanceof StackTraceElement))
286 return false;
287 StackTraceElement e = (StackTraceElement)obj;
288 return e.declaringClass.equals(declaringClass) &&
289 Objects.equals(moduleName, e.moduleName) &&
290 Objects.equals(moduleVersion, e.moduleVersion) &&
291 e.lineNumber == lineNumber &&
292 Objects.equals(methodName, e.methodName) &&
293 Objects.equals(fileName, e.fileName);
294 }
295
296 /**
297 * Returns a hash code value for this stack trace element.
298 */
299 public int hashCode() {
300 int result = 31*declaringClass.hashCode() + methodName.hashCode();
301 result = 31*result + Objects.hashCode(moduleName);
302 result = 31*result + Objects.hashCode(moduleVersion);
303 result = 31*result + Objects.hashCode(fileName);
304 result = 31*result + lineNumber;
305 return result;
306 }
307
308 private static final long serialVersionUID = 6992337162326171013L;
309 }
|
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
26 package java.lang;
27
28 import jdk.internal.loader.BuiltinClassLoader;
29 import jdk.internal.misc.SharedSecrets;
30 import jdk.internal.misc.VM;
31 import jdk.internal.module.ModuleHashes;
32
33 import java.lang.module.ModuleDescriptor.Version;
34 import java.lang.reflect.Layer;
35 import java.lang.reflect.Module;
36 import java.util.HashSet;
37 import java.util.Objects;
38 import java.util.Optional;
39 import java.util.Set;
40
41 /**
42 * An element in a stack trace, as returned by {@link
43 * Throwable#getStackTrace()}. Each element represents a single stack frame.
44 * All stack frames except for the one at the top of the stack represent
45 * a method invocation. The frame at the top of the stack represents the
46 * execution point at which the stack trace was generated. Typically,
47 * this is the point at which the throwable corresponding to the stack trace
48 * was created.
49 *
50 * @since 1.4
51 * @author Josh Bloch
52 */
53 public final class StackTraceElement implements java.io.Serializable {
54 // This field is set to the compacted String representation used
55 // by StackTraceElement::toString and stored in serial form.
56 //
57 // This field is of Object type. VM initially sets this field to
58 // the Class object of the declaring class to build the compacted string.
59 private Object classOrLoaderModuleClassName;
60
61 // Normally initialized by VM
62 private String classLoaderName;
63 private String moduleName;
64 private String moduleVersion;
65 private String declaringClass;
66 private String methodName;
67 private String fileName;
68 private int lineNumber;
69
70 /**
71 * Creates a stack trace element representing the specified execution
72 * point. The {@link #getModuleName module name} and {@link
73 * #getModuleVersion module version} of the stack trace element will
74 * be {@code null}.
75 *
76 * @param declaringClass the fully qualified name of the class containing
77 * the execution point represented by the stack trace element
78 * @param methodName the name of the method containing the execution point
79 * represented by the stack trace element
80 * @param fileName the name of the file containing the execution point
81 * represented by the stack trace element, or {@code null} if
82 * this information is unavailable
83 * @param lineNumber the line number of the source line containing the
84 * execution point represented by this stack trace element, or
85 * a negative number if this information is unavailable. A value
86 * of -2 indicates that the method containing the execution point
87 * is a native method
88 * @throws NullPointerException if {@code declaringClass} or
89 * {@code methodName} is null
90 * @since 1.5
91 */
92 public StackTraceElement(String declaringClass, String methodName,
93 String fileName, int lineNumber) {
94 this(null, null, null, declaringClass, methodName, fileName, lineNumber);
95 }
96
97 /**
98 * Creates a stack trace element representing the specified execution
99 * point.
100 *
101 * @param classLoaderName the class loader name if the class loader of
102 * the class containing the execution point represented by
103 * the stack trace is named; otherwise {@code null}
104 * @param moduleName the module name if the class containing the
105 * execution point represented by the stack trace is in a named
106 * module; otherwise {@code null}
107 * @param moduleVersion the module version if the class containing the
108 * execution point represented by the stack trace is in a named
109 * module that has a version; otherwise {@code null}
110 * @param declaringClass the fully qualified name of the class containing
111 * the execution point represented by the stack trace element
112 * @param methodName the name of the method containing the execution point
113 * represented by the stack trace element
114 * @param fileName the name of the file containing the execution point
115 * represented by the stack trace element, or {@code null} if
116 * this information is unavailable
117 * @param lineNumber the line number of the source line containing the
118 * execution point represented by this stack trace element, or
119 * a negative number if this information is unavailable. A value
120 * of -2 indicates that the method containing the execution point
121 * is a native method
122 *
123 * @throws IllegalArgumentException if {@code classLoaderName},
124 * {@code moduleName} or {@code moduleVersion} is an empty string
125 * @throws NullPointerException if {@code declaringClass} is {@code null}
126 * or {@code methodName} is {@code null}
127 *
128 * @since 9
129 */
130 public StackTraceElement(String classLoaderName,
131 String moduleName, String moduleVersion,
132 String declaringClass, String methodName,
133 String fileName, int lineNumber) {
134 this.classLoaderName = requireNonEmpty(classLoaderName, "classLoaderName");
135 this.moduleName = requireNonEmpty(moduleName, "moduleName");
136 this.moduleVersion = requireNonEmpty(moduleVersion, "moduleVersion");
137 this.declaringClass = Objects.requireNonNull(declaringClass, "Declaring class is null");
138 this.methodName = Objects.requireNonNull(methodName, "Method name is null");
139 this.fileName = fileName;
140 this.lineNumber = lineNumber;
141 }
142
143 private static String requireNonEmpty(String name, String paramName) {
144 if (name != null && name.isEmpty()) {
145 throw new IllegalArgumentException(paramName +
146 " must be non-empty or null");
147 }
148 return name;
149 }
150
151 /*
152 * Private constructor for the factory methods to create StackTraceElement
153 * for Throwable and StackFrameInfo
154 */
155 private StackTraceElement() {}
156
157 /**
158 * Returns the name of the source file containing the execution point
159 * represented by this stack trace element. Generally, this corresponds
160 * to the {@code SourceFile} attribute of the relevant {@code class}
161 * file (as per <i>The Java Virtual Machine Specification</i>, Section
162 * 4.7.7). In some systems, the name may refer to some source code unit
163 * other than a file, such as an entry in source repository.
164 *
165 * @return the name of the file containing the execution point
166 * represented by this stack trace element, or {@code null} if
167 * this information is unavailable.
168 */
169 public String getFileName() {
170 return fileName;
171 }
172
173 /**
174 * Returns the line number of the source line containing the execution
175 * point represented by this stack trace element. Generally, this is
197 */
198 public String getModuleName() {
199 return moduleName;
200 }
201
202 /**
203 * Returns the module version of the module containing the execution point
204 * represented by this stack trace element.
205 *
206 * @return the module version of the {@code Module} containing the execution
207 * point represented by this stack trace element; {@code null}
208 * if the module version is not available.
209 * @since 9
210 * @see java.lang.module.ModuleDescriptor.Version
211 */
212 public String getModuleVersion() {
213 return moduleVersion;
214 }
215
216 /**
217 * Returns the name of the class loader of the class containing the
218 * execution point represented by this stack trace element.
219 *
220 * @return the name of the class loader of the class containing the execution
221 * point represented by this stack trace element; {@code null}
222 * if the class loader is not named.
223 *
224 * @since 9
225 * @see java.lang.ClassLoader#getName()
226 */
227 public String getClassLoaderName() {
228 return classLoaderName;
229 }
230
231 /**
232 * Returns the fully qualified name of the class containing the
233 * execution point represented by this stack trace element.
234 *
235 * @return the fully qualified name of the {@code Class} containing
236 * the execution point represented by this stack trace element.
237 */
238 public String getClassName() {
239 return declaringClass;
240 }
241
242 /**
243 * Returns the name of the method containing the execution point
244 * represented by this stack trace element. If the execution point is
245 * contained in an instance or class initializer, this method will return
246 * the appropriate <i>special method name</i>, {@code <init>} or
247 * {@code <clinit>}, as per Section 3.9 of <i>The Java Virtual
248 * Machine Specification</i>.
249 *
250 * @return the name of the method containing the execution point
251 * represented by this stack trace element.
254 return methodName;
255 }
256
257 /**
258 * Returns true if the method containing the execution point
259 * represented by this stack trace element is a native method.
260 *
261 * @return {@code true} if the method containing the execution point
262 * represented by this stack trace element is a native method.
263 */
264 public boolean isNativeMethod() {
265 return lineNumber == -2;
266 }
267
268 /**
269 * Returns a string representation of this stack trace element. The
270 * format of this string depends on the implementation, but the following
271 * examples may be regarded as typical:
272 * <ul>
273 * <li>
274 * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Main.java:101)}"
275 * - See the description below.
276 * </li>
277 * <li>
278 * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Main.java)}"
279 * - The line number is unavailable.
280 * </li>
281 * <li>
282 * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Unknown Source)}"
283 * - Neither the file name nor the line number is available.
284 * </li>
285 * <li>
286 * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Native Method)}"
287 * - The method containing the execution point is a native method.
288 * </li>
289 * <li>
290 * "{@code com.foo.loader//com.foo.bar.App.run(App.java:12)}"
291 * - The class of the execution point is defined in the unnamed module of
292 * the class loader named {@code com.foo.loader}.
293 * </li>
294 * <li>
295 * "{@code acme@2.1/org.acme.Lib.test(Lib.java:80)}"
296 * - The class of the execution point is defined in {@code acme} module
297 * loaded by by a built-in class loader such as the application class loader.
298 * </li>
299 * <li>
300 * "{@code MyClass.mash(MyClass.java:9)}"
301 * - {@code MyClass} class is on the application class path.
302 * </li>
303 * </ul>
304 *
305 * <p> The first example shows a stack trace element consisting of
306 * three elements, each separated by {@code "/"} followed with
307 * the source file name and the line number of the source line
308 * containing the execution point.
309 *
310 * The first element "{@code com.foo.loader}" is
311 * the name of the class loader. The second element "{@code foo@9.0}"
312 * is the module name and version. The third element is the method
313 * containing the execution point; "{@code com.foo.Main"}" is the
314 * fully-qualified class name and "{@code run}" is the name of the method.
315 * "{@code Main.java}" is the source file name and "{@code 101}" is
316 * the line number.
317 *
318 * <p> If a class is defined in an <em>unnamed module</em>
319 * then the second element is omitted as shown in
320 * "{@code com.foo.loader//com.foo.bar.App.run(App.java:12)}".
321 *
322 * If the class loader is a <a href="ClassLoader.html#builtinLoaders">
323 * built-in class loader</a> or is not named then the first element
324 * and its following {@code "/"} are omitted as shown in
325 * "{@code acme@2.1/org.acme.Lib.test(Lib.java:80)}".
326 * If the first element is omitted and the module is an unnamed module,
327 * the second element and its following {@code "/"} are also omitted
328 * as shown in "{@code MyClass.mash(MyClass.java:9)}".
329 *
330 * @see Throwable#printStackTrace()
331 */
332 public String toString() {
333 String s = buildLoaderModuleClassName();
334 if (s == null) {
335 // all elements will be included
336 s = "";
337 if (classLoaderName != null && !classLoaderName.isEmpty()) {
338 s += classLoaderName + "/";
339 }
340 if (moduleName != null && !moduleName.isEmpty()) {
341 s += moduleName;
342 }
343 if (moduleVersion != null && !moduleVersion.isEmpty()) {
344 s += "@" + moduleVersion;
345 }
346 s = s.isEmpty() ? declaringClass : s + "/" + declaringClass;
347 }
348
349 return s + "." + methodName + "(" +
350 (isNativeMethod() ? "Native Method)" :
351 (fileName != null && lineNumber >= 0 ?
352 fileName + ":" + lineNumber + ")" :
353 (fileName != null ? ""+fileName+")" : "Unknown Source)")));
354 }
355
356 /**
357 * Returns true if the specified object is another
358 * {@code StackTraceElement} instance representing the same execution
359 * point as this instance. Two stack trace elements {@code a} and
360 * {@code b} are equal if and only if:
361 * <pre>{@code
362 * equals(a.getClassLoaderName(), b.getClassLoaderName()) &&
363 * equals(a.getModuleName(), b.getModuleName()) &&
364 * equals(a.getModuleVersion(), b.getModuleVersion()) &&
365 * equals(a.getClassName(), b.getClassName()) &&
366 * equals(a.getMethodName(), b.getMethodName())
367 * equals(a.getFileName(), b.getFileName()) &&
368 * a.getLineNumber() == b.getLineNumber()
369 *
370 * }</pre>
371 * where {@code equals} has the semantics of {@link
372 * java.util.Objects#equals(Object, Object) Objects.equals}.
373 *
374 * @param obj the object to be compared with this stack trace element.
375 * @return true if the specified object is another
376 * {@code StackTraceElement} instance representing the same
377 * execution point as this instance.
378 */
379 public boolean equals(Object obj) {
380 if (obj==this)
381 return true;
382 if (!(obj instanceof StackTraceElement))
383 return false;
384 StackTraceElement e = (StackTraceElement)obj;
385 return Objects.equals(classLoaderName, e.classLoaderName) &&
386 Objects.equals(moduleName, e.moduleName) &&
387 Objects.equals(moduleVersion, e.moduleVersion) &&
388 e.declaringClass.equals(declaringClass) &&
389 e.lineNumber == lineNumber &&
390 Objects.equals(methodName, e.methodName) &&
391 Objects.equals(fileName, e.fileName);
392 }
393
394 /**
395 * Returns a hash code value for this stack trace element.
396 */
397 public int hashCode() {
398 int result = 31*declaringClass.hashCode() + methodName.hashCode();
399 result = 31*result + Objects.hashCode(classLoaderName);
400 result = 31*result + Objects.hashCode(moduleName);
401 result = 31*result + Objects.hashCode(moduleVersion);
402 result = 31*result + Objects.hashCode(fileName);
403 result = 31*result + lineNumber;
404 return result;
405 }
406
407
408 /**
409 * Build the compacted String representation to be returned by
410 * toString method from the declaring Class object.
411 */
412 synchronized String buildLoaderModuleClassName() {
413 if (classOrLoaderModuleClassName == null)
414 return null;
415
416 if (classOrLoaderModuleClassName instanceof Class) {
417 Class<?> cls = (Class<?>)classOrLoaderModuleClassName;
418 classOrLoaderModuleClassName = toLoaderModuleClassName(cls);
419 }
420 return (String)classOrLoaderModuleClassName;
421 }
422
423 /**
424 * Returns <loader>/<module>/<fully-qualified-classname> string
425 * representation of the given class.
426 * <p>
427 * If the module is a non-upgradeable JDK module then omit
428 * its version string.
429 * <p>
430 * If the loader has no name, or if the loader is one of the built-in
431 * loaders (`boot`, `platform`, or `app`) then drop the first element
432 * (`<loader>/`).
433 * <p>
434 * If the first element has been dropped and the module is unnamed
435 * then drop the second element (`<module>/`).
436 * <p>
437 * If the first element is not dropped and the module is unnamed
438 * then drop `<module>`.
439 */
440 private static String toLoaderModuleClassName(Class<?> cls) {
441 ClassLoader loader = cls.getClassLoader0();
442 Module m = cls.getModule();
443
444 // First element - class loader name
445 // Call package-private ClassLoader::name method
446 String s = "";
447 if (loader != null && loader.name() != null &&
448 !(loader instanceof BuiltinClassLoader)) {
449 s = loader.name() + "/";
450 }
451
452 // Second element - module name and version
453 if (m != null && m.isNamed()) {
454 s += m.getName();
455 // Include version if it is a user module or upgradeable module
456 //
457 // If it is JDK non-upgradeable module which is recorded
458 // in the hashes in java.base, omit the version.
459 if (!isHashedInJavaBase(m)) {
460 Optional<Version> ov = m.getDescriptor().version();
461 if (ov.isPresent()) {
462 String version = "@" + ov.get().toString();
463 s += version;
464 }
465 }
466 }
467
468 // fully-qualified class name
469 return s.isEmpty() ? cls.getName() : s + "/" + cls.getName();
470 }
471
472 /**
473 * Returns true if the module is hashed with java.base.
474 * <p>
475 * This method returns false when running on the exploded image
476 * since JDK modules are not hashed. They have no Version attribute
477 * and so "@<version>" part will be omitted anyway.
478 */
479 private static boolean isHashedInJavaBase(Module m) {
480 // return true if module system is not initialized as the code
481 // must be in java.base
482 if (!VM.isModuleSystemInited())
483 return true;
484
485 return Layer.boot() == m.getLayer() && HashedModules.contains(m);
486 }
487
488 /*
489 * Finds JDK non-upgradeable modules, i.e. the modules that are
490 * included in the hashes in java.base.
491 */
492 private static class HashedModules {
493 static Set<String> HASHED_MODULES = hashedModules();
494
495 static Set<String> hashedModules() {
496 Module javaBase = Layer.boot().findModule("java.base").get();
497 Optional<ModuleHashes> ohashes =
498 SharedSecrets.getJavaLangModuleAccess()
499 .hashes(javaBase.getDescriptor());
500
501 if (ohashes.isPresent()) {
502 Set<String> names = new HashSet<>(ohashes.get().names());
503 names.add("java.base");
504 return names;
505 }
506
507 return Set.of();
508 }
509
510 static boolean contains(Module m) {
511 return HASHED_MODULES.contains(m.getName());
512 }
513 }
514
515
516 /*
517 * Returns a StackTraceElement from a given StackFrameInfo.
518 */
519 static StackTraceElement of(StackFrameInfo sfi) {
520 StackTraceElement ste = new StackTraceElement();
521 ste.fillFromStackFrameInfo(sfi);
522 ste.buildLoaderModuleClassName();
523 return ste;
524 }
525
526 /*
527 * Returns an array of StackTraceElements of the given depth
528 * filled from the backtrace of a given Throwable.
529 */
530 static StackTraceElement[] of(Throwable x, int depth) {
531 StackTraceElement[] stackTrace = new StackTraceElement[depth];
532 for (int i = 0; i < depth; i++) {
533 stackTrace[i] = new StackTraceElement();
534 }
535
536 // VM to fill in StackTraceElement
537 fillStackTraceFromThrowable(stackTrace, x);
538
539 // ensure the proper StackTraceElement initialization
540 for (StackTraceElement ste : stackTrace) {
541 ste.buildLoaderModuleClassName();
542 }
543 return stackTrace;
544 }
545
546 /*
547 * Fill in the stack trace elements from a given Throwable.
548 */
549 private static native void fillStackTraceFromThrowable(StackTraceElement[] elements,
550 Throwable x);
551 /*
552 * Fill in the stack trace elements from a given StackFrameInfo.
553 */
554 private native void fillFromStackFrameInfo(StackFrameInfo sfi);
555
556 private static final long serialVersionUID = 6992337162326171013L;
557 }
|