diff -r 388e48c0a37a -r 05224402145d emul/src/main/java/java/lang/Throwable.java --- a/emul/src/main/java/java/lang/Throwable.java Wed Jan 23 20:16:48 2013 +0100 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,1088 +0,0 @@ -/* - * Copyright (c) 1994, 2011, Oracle and/or its affiliates. All rights reserved. - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This code is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 only, as - * published by the Free Software Foundation. Oracle designates this - * particular file as subject to the "Classpath" exception as provided - * by Oracle in the LICENSE file that accompanied this code. - * - * This code is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * version 2 for more details (a copy is included in the LICENSE file that - * accompanied this code). - * - * You should have received a copy of the GNU General Public License version - * 2 along with this work; if not, write to the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. - * - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA - * or visit www.oracle.com if you need additional information or have any - * questions. - */ - -package java.lang; -import java.io.*; -import org.apidesign.bck2brwsr.core.JavaScriptBody; -import org.apidesign.bck2brwsr.core.JavaScriptOnly; - -/** - * The {@code Throwable} class is the superclass of all errors and - * exceptions in the Java language. Only objects that are instances of this - * class (or one of its subclasses) are thrown by the Java Virtual Machine or - * can be thrown by the Java {@code throw} statement. Similarly, only - * this class or one of its subclasses can be the argument type in a - * {@code catch} clause. - * - * For the purposes of compile-time checking of exceptions, {@code - * Throwable} and any subclass of {@code Throwable} that is not also a - * subclass of either {@link RuntimeException} or {@link Error} are - * regarded as checked exceptions. - * - *
Instances of two subclasses, {@link java.lang.Error} and - * {@link java.lang.Exception}, are conventionally used to indicate - * that exceptional situations have occurred. Typically, these instances - * are freshly created in the context of the exceptional situation so - * as to include relevant information (such as stack trace data). - * - *
A throwable contains a snapshot of the execution stack of its - * thread at the time it was created. It can also contain a message - * string that gives more information about the error. Over time, a - * throwable can {@linkplain Throwable#addSuppressed suppress} other - * throwables from being propagated. Finally, the throwable can also - * contain a cause: another throwable that caused this - * throwable to be constructed. The recording of this causal information - * is referred to as the chained exception facility, as the - * cause can, itself, have a cause, and so on, leading to a "chain" of - * exceptions, each caused by another. - * - *
One reason that a throwable may have a cause is that the class that - * throws it is built atop a lower layered abstraction, and an operation on - * the upper layer fails due to a failure in the lower layer. It would be bad - * design to let the throwable thrown by the lower layer propagate outward, as - * it is generally unrelated to the abstraction provided by the upper layer. - * Further, doing so would tie the API of the upper layer to the details of - * its implementation, assuming the lower layer's exception was a checked - * exception. Throwing a "wrapped exception" (i.e., an exception containing a - * cause) allows the upper layer to communicate the details of the failure to - * its caller without incurring either of these shortcomings. It preserves - * the flexibility to change the implementation of the upper layer without - * changing its API (in particular, the set of exceptions thrown by its - * methods). - * - *
A second reason that a throwable may have a cause is that the method - * that throws it must conform to a general-purpose interface that does not - * permit the method to throw the cause directly. For example, suppose - * a persistent collection conforms to the {@link java.util.Collection - * Collection} interface, and that its persistence is implemented atop - * {@code java.io}. Suppose the internals of the {@code add} method - * can throw an {@link java.io.IOException IOException}. The implementation - * can communicate the details of the {@code IOException} to its caller - * while conforming to the {@code Collection} interface by wrapping the - * {@code IOException} in an appropriate unchecked exception. (The - * specification for the persistent collection should indicate that it is - * capable of throwing such exceptions.) - * - *
A cause can be associated with a throwable in two ways: via a - * constructor that takes the cause as an argument, or via the - * {@link #initCause(Throwable)} method. New throwable classes that - * wish to allow causes to be associated with them should provide constructors - * that take a cause and delegate (perhaps indirectly) to one of the - * {@code Throwable} constructors that takes a cause. - * - * Because the {@code initCause} method is public, it allows a cause to be - * associated with any throwable, even a "legacy throwable" whose - * implementation predates the addition of the exception chaining mechanism to - * {@code Throwable}. - * - *
By convention, class {@code Throwable} and its subclasses have two
- * constructors, one that takes no arguments and one that takes a
- * {@code String} argument that can be used to produce a detail message.
- * Further, those subclasses that might likely have a cause associated with
- * them should have two more constructors, one that takes a
- * {@code Throwable} (the cause), and one that takes a
- * {@code String} (the detail message) and a {@code Throwable} (the
- * cause).
- *
- * @author unascribed
- * @author Josh Bloch (Added exception chaining and programmatic access to
- * stack trace in 1.4.)
- * @jls 11.2 Compile-Time Checking of Exceptions
- * @since JDK1.0
- */
-public class Throwable implements Serializable {
- /** use serialVersionUID from JDK 1.0.2 for interoperability */
- private static final long serialVersionUID = -3042686055658047285L;
-
- /**
- * Native code saves some indication of the stack backtrace in this slot.
- */
- private transient Object backtrace;
-
- /**
- * Specific details about the Throwable. For example, for
- * {@code FileNotFoundException}, this contains the name of
- * the file that could not be found.
- *
- * @serial
- */
- private String detailMessage;
-
-
- /**
- * Holder class to defer initializing sentinel objects only used
- * for serialization.
- */
- private static class SentinelHolder {
- /**
- * {@linkplain #setStackTrace(StackTraceElement[]) Setting the
- * stack trace} to a one-element array containing this sentinel
- * value indicates future attempts to set the stack trace will be
- * ignored. The sentinal is equal to the result of calling: The {@link #fillInStackTrace()} method is called to initialize
- * the stack trace data in the newly created throwable.
- */
- public Throwable() {
- fillInStackTrace();
- }
-
- /**
- * Constructs a new throwable with the specified detail message. The
- * cause is not initialized, and may subsequently be initialized by
- * a call to {@link #initCause}.
- *
- * The {@link #fillInStackTrace()} method is called to initialize
- * the stack trace data in the newly created throwable.
- *
- * @param message the detail message. The detail message is saved for
- * later retrieval by the {@link #getMessage()} method.
- */
- public Throwable(String message) {
- fillInStackTrace();
- detailMessage = message;
- }
-
- /**
- * Constructs a new throwable with the specified detail message and
- * cause. Note that the detail message associated with
- * {@code cause} is not automatically incorporated in
- * this throwable's detail message.
- *
- * The {@link #fillInStackTrace()} method is called to initialize
- * the stack trace data in the newly created throwable.
- *
- * @param message the detail message (which is saved for later retrieval
- * by the {@link #getMessage()} method).
- * @param cause the cause (which is saved for later retrieval by the
- * {@link #getCause()} method). (A {@code null} value is
- * permitted, and indicates that the cause is nonexistent or
- * unknown.)
- * @since 1.4
- */
- public Throwable(String message, Throwable cause) {
- fillInStackTrace();
- detailMessage = message;
- this.cause = cause;
- }
-
- /**
- * Constructs a new throwable with the specified cause and a detail
- * message of {@code (cause==null ? null : cause.toString())} (which
- * typically contains the class and detail message of {@code cause}).
- * This constructor is useful for throwables that are little more than
- * wrappers for other throwables (for example, {@link
- * java.security.PrivilegedActionException}).
- *
- * The {@link #fillInStackTrace()} method is called to initialize
- * the stack trace data in the newly created throwable.
- *
- * @param cause the cause (which is saved for later retrieval by the
- * {@link #getCause()} method). (A {@code null} value is
- * permitted, and indicates that the cause is nonexistent or
- * unknown.)
- * @since 1.4
- */
- public Throwable(Throwable cause) {
- fillInStackTrace();
- detailMessage = (cause==null ? null : cause.toString());
- this.cause = cause;
- }
-
- /**
- * Constructs a new throwable with the specified detail message,
- * cause, {@linkplain #addSuppressed suppression} enabled or
- * disabled, and writable stack trace enabled or disabled. If
- * suppression is disabled, {@link #getSuppressed} for this object
- * will return a zero-length array and calls to {@link
- * #addSuppressed} that would otherwise append an exception to the
- * suppressed list will have no effect. If the writable stack
- * trace is false, this constructor will not call {@link
- * #fillInStackTrace()}, a {@code null} will be written to the
- * {@code stackTrace} field, and subsequent calls to {@code
- * fillInStackTrace} and {@link
- * #setStackTrace(StackTraceElement[])} will not set the stack
- * trace. If the writable stack trace is false, {@link
- * #getStackTrace} will return a zero length array.
- *
- * Note that the other constructors of {@code Throwable} treat
- * suppression as being enabled and the stack trace as being
- * writable. Subclasses of {@code Throwable} should document any
- * conditions under which suppression is disabled and document
- * conditions under which the stack trace is not writable.
- * Disabling of suppression should only occur in exceptional
- * circumstances where special requirements exist, such as a
- * virtual machine reusing exception objects under low-memory
- * situations. Circumstances where a given exception object is
- * repeatedly caught and rethrown, such as to implement control
- * flow between two sub-systems, is another situation where
- * immutable throwable objects would be appropriate.
- *
- * @param message the detail message.
- * @param cause the cause. (A {@code null} value is permitted,
- * and indicates that the cause is nonexistent or unknown.)
- * @param enableSuppression whether or not suppression is enabled or disabled
- * @param writableStackTrace whether or not the stack trace should be
- * writable
- *
- * @see OutOfMemoryError
- * @see NullPointerException
- * @see ArithmeticException
- * @since 1.7
- */
- protected Throwable(String message, Throwable cause,
- boolean enableSuppression,
- boolean writableStackTrace) {
- if (writableStackTrace) {
- fillInStackTrace();
- } else {
- stackTrace = null;
- }
- detailMessage = message;
- this.cause = cause;
-// if (!enableSuppression)
-// suppressedExceptions = null;
- }
-
- /**
- * Returns the detail message string of this throwable.
- *
- * @return the detail message string of this {@code Throwable} instance
- * (which may be {@code null}).
- */
- public String getMessage() {
- return detailMessage;
- }
-
- /**
- * Creates a localized description of this throwable.
- * Subclasses may override this method in order to produce a
- * locale-specific message. For subclasses that do not override this
- * method, the default implementation returns the same result as
- * {@code getMessage()}.
- *
- * @return The localized description of this throwable.
- * @since JDK1.1
- */
- public String getLocalizedMessage() {
- return getMessage();
- }
-
- /**
- * Returns the cause of this throwable or {@code null} if the
- * cause is nonexistent or unknown. (The cause is the throwable that
- * caused this throwable to get thrown.)
- *
- * This implementation returns the cause that was supplied via one of
- * the constructors requiring a {@code Throwable}, or that was set after
- * creation with the {@link #initCause(Throwable)} method. While it is
- * typically unnecessary to override this method, a subclass can override
- * it to return a cause set by some other means. This is appropriate for
- * a "legacy chained throwable" that predates the addition of chained
- * exceptions to {@code Throwable}. Note that it is not
- * necessary to override any of the {@code PrintStackTrace} methods,
- * all of which invoke the {@code getCause} method to determine the
- * cause of a throwable.
- *
- * @return the cause of this throwable or {@code null} if the
- * cause is nonexistent or unknown.
- * @since 1.4
- */
- public synchronized Throwable getCause() {
- return (cause==this ? null : cause);
- }
-
- /**
- * Initializes the cause of this throwable to the specified value.
- * (The cause is the throwable that caused this throwable to get thrown.)
- *
- * This method can be called at most once. It is generally called from
- * within the constructor, or immediately after creating the
- * throwable. If this throwable was created
- * with {@link #Throwable(Throwable)} or
- * {@link #Throwable(String,Throwable)}, this method cannot be called
- * even once.
- *
- * An example of using this method on a legacy throwable type
- * without other support for setting the cause is:
- *
- * An exception can have both a cause and one or more suppressed
- * exceptions:
- * If the stack trace of this {@code Throwable} {@linkplain
- * Throwable#Throwable(String, Throwable, boolean, boolean) is not
- * writable}, calling this method has no effect.
- *
- * @return a reference to this {@code Throwable} instance.
- * @see java.lang.Throwable#printStackTrace()
- */
- public synchronized Throwable fillInStackTrace() {
- if (stackTrace != null ||
- backtrace != null /* Out of protocol state */ ) {
- fillInStackTrace(0);
- stackTrace = UNASSIGNED_STACK;
- }
- return this;
- }
-
- @JavaScriptBody(args = { "dummy" }, body = "")
- private native Throwable fillInStackTrace(int dummy);
-
- /**
- * Provides programmatic access to the stack trace information printed by
- * {@link #printStackTrace()}. Returns an array of stack trace elements,
- * each representing one stack frame. The zeroth element of the array
- * (assuming the array's length is non-zero) represents the top of the
- * stack, which is the last method invocation in the sequence. Typically,
- * this is the point at which this throwable was created and thrown.
- * The last element of the array (assuming the array's length is non-zero)
- * represents the bottom of the stack, which is the first method invocation
- * in the sequence.
- *
- * Some virtual machines may, under some circumstances, omit one
- * or more stack frames from the stack trace. In the extreme case,
- * a virtual machine that has no stack trace information concerning
- * this throwable is permitted to return a zero-length array from this
- * method. Generally speaking, the array returned by this method will
- * contain one element for every frame that would be printed by
- * {@code printStackTrace}. Writes to the returned array do not
- * affect future calls to this method.
- *
- * @return an array of stack trace elements representing the stack trace
- * pertaining to this throwable.
- * @since 1.4
- */
- public StackTraceElement[] getStackTrace() {
- return getOurStackTrace().clone();
- }
-
- private synchronized StackTraceElement[] getOurStackTrace() {
- // Initialize stack trace field with information from
- // backtrace if this is the first call to this method
- if (stackTrace == UNASSIGNED_STACK ||
- (stackTrace == null && backtrace != null) /* Out of protocol state */) {
- int depth = getStackTraceDepth();
- stackTrace = new StackTraceElement[depth];
- for (int i=0; i < depth; i++)
- stackTrace[i] = getStackTraceElement(i);
- } else if (stackTrace == null) {
- return UNASSIGNED_STACK;
- }
- return stackTrace;
- }
-
- /**
- * Sets the stack trace elements that will be returned by
- * {@link #getStackTrace()} and printed by {@link #printStackTrace()}
- * and related methods.
- *
- * This method, which is designed for use by RPC frameworks and other
- * advanced systems, allows the client to override the default
- * stack trace that is either generated by {@link #fillInStackTrace()}
- * when a throwable is constructed or deserialized when a throwable is
- * read from a serialization stream.
- *
- * If the stack trace of this {@code Throwable} {@linkplain
- * Throwable#Throwable(String, Throwable, boolean, boolean) is not
- * writable}, calling this method has no effect other than
- * validating its argument.
- *
- * @param stackTrace the stack trace elements to be associated with
- * this {@code Throwable}. The specified array is copied by this
- * call; changes in the specified array after the method invocation
- * returns will have no affect on this {@code Throwable}'s stack
- * trace.
- *
- * @throws NullPointerException if {@code stackTrace} is
- * {@code null} or if any of the elements of
- * {@code stackTrace} are {@code null}
- *
- * @since 1.4
- */
- public void setStackTrace(StackTraceElement[] stackTrace) {
- // Validate argument
- StackTraceElement[] defensiveCopy = stackTrace.clone();
- for (int i = 0; i < defensiveCopy.length; i++) {
- if (defensiveCopy[i] == null)
- throw new NullPointerException("stackTrace[" + i + "]");
- }
-
- synchronized (this) {
- if (this.stackTrace == null && // Immutable stack
- backtrace == null) // Test for out of protocol state
- return;
- this.stackTrace = defensiveCopy;
- }
- }
-
- /**
- * Returns the number of elements in the stack trace (or 0 if the stack
- * trace is unavailable).
- *
- * package-protection for use by SharedSecrets.
- */
- native int getStackTraceDepth();
-
- /**
- * Returns the specified element of the stack trace.
- *
- * package-protection for use by SharedSecrets.
- *
- * @param index index of the element to return.
- * @throws IndexOutOfBoundsException if {@code index < 0 ||
- * index >= getStackTraceDepth() }
- */
- native StackTraceElement getStackTraceElement(int index);
-
- /**
- * Reads a {@code Throwable} from a stream, enforcing
- * well-formedness constraints on fields. Null entries and
- * self-pointers are not allowed in the list of {@code
- * suppressedExceptions}. Null entries are not allowed for stack
- * trace elements. A null stack trace in the serial form results
- * in a zero-length stack element array. A single-element stack
- * trace whose entry is equal to {@code new StackTraceElement("",
- * "", null, Integer.MIN_VALUE)} results in a {@code null} {@code
- * stackTrace} field.
- *
- * Note that there are no constraints on the value the {@code
- * cause} field can hold; both {@code null} and {@code this} are
- * valid values for the field.
- */
-// private void readObject(ObjectInputStream s)
-// throws IOException, ClassNotFoundException {
-// s.defaultReadObject(); // read in all fields
-// if (suppressedExceptions != null) {
-// List The suppression behavior is enabled unless disabled
- * {@linkplain #Throwable(String, Throwable, boolean, boolean) via
- * a constructor}. When suppression is disabled, this method does
- * nothing other than to validate its argument.
- *
- * Note that when one exception {@linkplain
- * #initCause(Throwable) causes} another exception, the first
- * exception is usually caught and then the second exception is
- * thrown in response. In other words, there is a causal
- * connection between the two exceptions.
- *
- * In contrast, there are situations where two independent
- * exceptions can be thrown in sibling code blocks, in particular
- * in the {@code try} block of a {@code try}-with-resources
- * statement and the compiler-generated {@code finally} block
- * which closes the resource.
- *
- * In these situations, only one of the thrown exceptions can be
- * propagated. In the {@code try}-with-resources statement, when
- * there are two such exceptions, the exception originating from
- * the {@code try} block is propagated and the exception from the
- * {@code finally} block is added to the list of exceptions
- * suppressed by the exception from the {@code try} block. As an
- * exception unwinds the stack, it can accumulate multiple
- * suppressed exceptions.
- *
- * An exception may have suppressed exceptions while also being
- * caused by another exception. Whether or not an exception has a
- * cause is semantically known at the time of its creation, unlike
- * whether or not an exception will suppress other exceptions
- * which is typically only determined after an exception is
- * thrown.
- *
- * Note that programmer written code is also able to take
- * advantage of calling this method in situations where there are
- * multiple sibling exceptions and only one can be propagated.
- *
- * @param exception the exception to be added to the list of
- * suppressed exceptions
- * @throws IllegalArgumentException if {@code exception} is this
- * throwable; a throwable cannot suppress itself.
- * @throws NullPointerException if {@code exception} is {@code null}
- * @since 1.7
- */
- public final synchronized void addSuppressed(Throwable exception) {
- if (exception == this)
- throw new IllegalArgumentException(SELF_SUPPRESSION_MESSAGE);
-
- if (exception == null)
- throw new NullPointerException(NULL_CAUSE_MESSAGE);
-
-// if (suppressedExceptions == null) // Suppressed exceptions not recorded
-// return;
-//
-// if (suppressedExceptions == SUPPRESSED_SENTINEL)
-// suppressedExceptions = new ArrayList
- * {@code new StackTraceElement("", "", null, Integer.MIN_VALUE)}
- */
- public static final StackTraceElement STACK_TRACE_ELEMENT_SENTINEL =
- new StackTraceElement("", "", null, Integer.MIN_VALUE);
-
- /**
- * Sentinel value used in the serial form to indicate an immutable
- * stack trace.
- */
- public static final StackTraceElement[] STACK_TRACE_SENTINEL =
- new StackTraceElement[] {STACK_TRACE_ELEMENT_SENTINEL};
- }
-
- /**
- * A shared value for an empty stack.
- */
- private static final StackTraceElement[] UNASSIGNED_STACK = new StackTraceElement[0];
-
- /*
- * To allow Throwable objects to be made immutable and safely
- * reused by the JVM, such as OutOfMemoryErrors, fields of
- * Throwable that are writable in response to user actions, cause,
- * stackTrace, and suppressedExceptions obey the following
- * protocol:
- *
- * 1) The fields are initialized to a non-null sentinel value
- * which indicates the value has logically not been set.
- *
- * 2) Writing a null to the field indicates further writes
- * are forbidden
- *
- * 3) The sentinel value may be replaced with another non-null
- * value.
- *
- * For example, implementations of the HotSpot JVM have
- * preallocated OutOfMemoryError objects to provide for better
- * diagnosability of that situation. These objects are created
- * without calling the constructor for that class and the fields
- * in question are initialized to null. To support this
- * capability, any new fields added to Throwable that require
- * being initialized to a non-null value require a coordinated JVM
- * change.
- */
-
- /**
- * The throwable that caused this throwable to get thrown, or null if this
- * throwable was not caused by another throwable, or if the causative
- * throwable is unknown. If this field is equal to this throwable itself,
- * it indicates that the cause of this throwable has not yet been
- * initialized.
- *
- * @serial
- * @since 1.4
- */
- private Throwable cause = this;
-
- /**
- * The stack trace, as returned by {@link #getStackTrace()}.
- *
- * The field is initialized to a zero-length array. A {@code
- * null} value of this field indicates subsequent calls to {@link
- * #setStackTrace(StackTraceElement[])} and {@link
- * #fillInStackTrace()} will be be no-ops.
- *
- * @serial
- * @since 1.4
- */
- private StackTraceElement[] stackTrace = UNASSIGNED_STACK;
-
- // Setting this static field introduces an acceptable
- // initialization dependency on a few java.util classes.
-// I don't think this dependency is acceptable
-// private static final List
- * try {
- * lowLevelOp();
- * } catch (LowLevelException le) {
- * throw (HighLevelException)
- * new HighLevelException().initCause(le); // Legacy constructor
- * }
- *
- *
- * @param cause the cause (which is saved for later retrieval by the
- * {@link #getCause()} method). (A {@code null} value is
- * permitted, and indicates that the cause is nonexistent or
- * unknown.)
- * @return a reference to this {@code Throwable} instance.
- * @throws IllegalArgumentException if {@code cause} is this
- * throwable. (A throwable cannot be its own cause.)
- * @throws IllegalStateException if this throwable was
- * created with {@link #Throwable(Throwable)} or
- * {@link #Throwable(String,Throwable)}, or this method has already
- * been called on this throwable.
- * @since 1.4
- */
- public synchronized Throwable initCause(Throwable cause) {
- if (this.cause != this)
- throw new IllegalStateException("Can't overwrite cause");
- if (cause == this)
- throw new IllegalArgumentException("Self-causation not permitted");
- this.cause = cause;
- return this;
- }
-
- /**
- * Returns a short description of this throwable.
- * The result is the concatenation of:
- *
- *
- * If {@code getLocalizedMessage} returns {@code null}, then just
- * the class name is returned.
- *
- * @return a string representation of this throwable.
- */
- public String toString() {
- String s = getClass().getName();
- String message = getLocalizedMessage();
- return (message != null) ? (s + ": " + message) : s;
- }
-
- /**
- * Prints this throwable and its backtrace to the
- * standard error stream. This method prints a stack trace for this
- * {@code Throwable} object on the error output stream that is
- * the value of the field {@code System.err}. The first line of
- * output contains the result of the {@link #toString()} method for
- * this object. Remaining lines represent data previously recorded by
- * the method {@link #fillInStackTrace()}. The format of this
- * information depends on the implementation, but the following
- * example may be regarded as typical:
- *
- * This example was produced by running the program:
- *
- * java.lang.NullPointerException
- * at MyClass.mash(MyClass.java:9)
- * at MyClass.crunch(MyClass.java:6)
- * at MyClass.main(MyClass.java:3)
- *
- * class MyClass {
- * public static void main(String[] args) {
- * crunch(null);
- * }
- * static void crunch(int[] a) {
- * mash(a);
- * }
- * static void mash(int[] b) {
- * System.out.println(b[0]);
- * }
- * }
- *
- * The backtrace for a throwable with an initialized, non-null cause
- * should generally include the backtrace for the cause. The format
- * of this information depends on the implementation, but the following
- * example may be regarded as typical:
- *
- * HighLevelException: MidLevelException: LowLevelException
- * at Junk.a(Junk.java:13)
- * at Junk.main(Junk.java:4)
- * Caused by: MidLevelException: LowLevelException
- * at Junk.c(Junk.java:23)
- * at Junk.b(Junk.java:17)
- * at Junk.a(Junk.java:11)
- * ... 1 more
- * Caused by: LowLevelException
- * at Junk.e(Junk.java:30)
- * at Junk.d(Junk.java:27)
- * at Junk.c(Junk.java:21)
- * ... 3 more
- *
- * Note the presence of lines containing the characters {@code "..."}.
- * These lines indicate that the remainder of the stack trace for this
- * exception matches the indicated number of frames from the bottom of the
- * stack trace of the exception that was caused by this exception (the
- * "enclosing" exception). This shorthand can greatly reduce the length
- * of the output in the common case where a wrapped exception is thrown
- * from same method as the "causative exception" is caught. The above
- * example was produced by running the program:
- *
- * public class Junk {
- * public static void main(String args[]) {
- * try {
- * a();
- * } catch(HighLevelException e) {
- * e.printStackTrace();
- * }
- * }
- * static void a() throws HighLevelException {
- * try {
- * b();
- * } catch(MidLevelException e) {
- * throw new HighLevelException(e);
- * }
- * }
- * static void b() throws MidLevelException {
- * c();
- * }
- * static void c() throws MidLevelException {
- * try {
- * d();
- * } catch(LowLevelException e) {
- * throw new MidLevelException(e);
- * }
- * }
- * static void d() throws LowLevelException {
- * e();
- * }
- * static void e() throws LowLevelException {
- * throw new LowLevelException();
- * }
- * }
- *
- * class HighLevelException extends Exception {
- * HighLevelException(Throwable cause) { super(cause); }
- * }
- *
- * class MidLevelException extends Exception {
- * MidLevelException(Throwable cause) { super(cause); }
- * }
- *
- * class LowLevelException extends Exception {
- * }
- *
- * As of release 7, the platform supports the notion of
- * suppressed exceptions (in conjunction with the {@code
- * try}-with-resources statement). Any exceptions that were
- * suppressed in order to deliver an exception are printed out
- * beneath the stack trace. The format of this information
- * depends on the implementation, but the following example may be
- * regarded as typical:
- *
- *
- * Exception in thread "main" java.lang.Exception: Something happened
- * at Foo.bar(Foo.java:10)
- * at Foo.main(Foo.java:5)
- * Suppressed: Resource$CloseFailException: Resource ID = 0
- * at Resource.close(Resource.java:26)
- * at Foo.bar(Foo.java:9)
- * ... 1 more
- *
- * Note that the "... n more" notation is used on suppressed exceptions
- * just at it is used on causes. Unlike causes, suppressed exceptions are
- * indented beyond their "containing exceptions."
- *
- *
- * Exception in thread "main" java.lang.Exception: Main block
- * at Foo3.main(Foo3.java:7)
- * Suppressed: Resource$CloseFailException: Resource ID = 2
- * at Resource.close(Resource.java:26)
- * at Foo3.main(Foo3.java:5)
- * Suppressed: Resource$CloseFailException: Resource ID = 1
- * at Resource.close(Resource.java:26)
- * at Foo3.main(Foo3.java:5)
- * Caused by: java.lang.Exception: I did it
- * at Foo3.main(Foo3.java:8)
- *
- * Likewise, a suppressed exception can have a cause:
- *
- * Exception in thread "main" java.lang.Exception: Main block
- * at Foo4.main(Foo4.java:6)
- * Suppressed: Resource2$CloseFailException: Resource ID = 1
- * at Resource2.close(Resource2.java:20)
- * at Foo4.main(Foo4.java:5)
- * Caused by: java.lang.Exception: Rats, you caught me
- * at Resource2$CloseFailException.
- */
-// public void printStackTrace() {
-// printStackTrace(System.err);
-// }
-//
-// /**
-// * Prints this throwable and its backtrace to the specified print stream.
-// *
-// * @param s {@code PrintStream} to use for output
-// */
-// public void printStackTrace(PrintStream s) {
-// printStackTrace(new WrappedPrintStream(s));
-// }
-//
-// private void printStackTrace(PrintStreamOrWriter s) {
-// // Guard against malicious overrides of Throwable.equals by
-// // using a Set with identity equality semantics.
-//// Set