jdk.jshell.SnippetEvent Maven / Gradle / Ivy
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/*
* Copyright (c) 2015, 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 jdk.jshell;
import jdk.jshell.Snippet.Status;
/**
* A description of a change to a Snippet. These are generated by direct changes
* to state with {@link JShell#eval(java.lang.String) JShell.eval(String)} or
* {@link JShell#drop(jdk.jshell.Snippet) JShell.drop(Snippet)},
* or indirectly by these same methods as
* dependencies change or Snippets are overwritten. For direct changes, the
* {@link SnippetEvent#causeSnippet()} is {@code null}.
*
* {@code SnippetEvent} is immutable: an access to
* any of its methods will always return the same result.
* and thus is thread-safe.
*
* @author Robert Field
* @since 9
*/
public class SnippetEvent {
SnippetEvent(Snippet snippet, Status previousStatus, Status status,
boolean isSignatureChange, Snippet causeSnippet,
String value, JShellException exception) {
this.snippet = snippet;
this.previousStatus = previousStatus;
this.status = status;
this.isSignatureChange = isSignatureChange;
this.causeSnippet = causeSnippet;
this.value = value;
this.exception = exception;
}
private final Snippet snippet;
private final Status previousStatus;
private final Status status;
private final boolean isSignatureChange;
private final Snippet causeSnippet;
private final String value;
private final JShellException exception;
/**
* The Snippet which has changed
* @return the return the Snippet whose {@code Status} has changed.
*/
public Snippet snippet() {
return snippet;
}
/**
* The status before the transition. If this event describes a Snippet
* creation return {@link Snippet.Status#NONEXISTENT NONEXISTENT}.
* @return the previousStatus
*/
public Status previousStatus() {
return previousStatus;
}
/**
* The after status. Note: this may be the same as the previous status (not
* all changes cause a {@code Status} change.
* @return the status
*/
public Status status() {
return status;
}
/**
* Indicates whether the signature has changed. Coming in or out of
* {@linkplain Status#isDefined() definition} is always a signature change.
* An overwritten Snippet
* {@link jdk.jshell.Snippet.Status#OVERWRITTEN (status == OVERWRITTEN)}
* is always {@code false} as responsibility for the
* definition has passed to the overwriting definition.
*
* @return {@code true} if the signature changed; otherwise {@code false}
*/
public boolean isSignatureChange() {
return isSignatureChange;
}
/**
* Either the snippet whose change caused this update or
* {@code null}. This returns {@code null} if this change is the
* creation of a new Snippet via
* {@link jdk.jshell.JShell#eval(java.lang.String) eval} or it is the
* explicit drop of a Snippet with
* {@link jdk.jshell.JShell#drop(jdk.jshell.Snippet) drop}.
*
* @return the Snippet which caused this change or {@code null} if
* directly caused by an API action.
*/
public Snippet causeSnippet() {
return causeSnippet;
}
/**
* An instance of {@link jdk.jshell.UnresolvedReferenceException}, if an unresolved reference was
* encountered, or an instance of {@link jdk.jshell.EvalException} if an exception was thrown
* during execution, otherwise {@code null}.
* @return the exception or {@code null}.
*/
public JShellException exception() {
return exception;
}
/**
* The result value of successful run. The value is null if not executed
* or an exception was thrown.
* @return the value or {@code null}.
*/
public String value() {
return value;
}
/**
* Return a string representation of the event
* @return a descriptive representation of the SnippetEvent
*/
@Override
public String toString() {
return "SnippetEvent(snippet=" + snippet +
",previousStatus=" + previousStatus +
",status=" + status +
",isSignatureChange=" + isSignatureChange +
",causeSnippet" + causeSnippet +
(value == null? "" : "value=" + value) +
(exception == null? "" : "exception=" + exception) +
")";
}
}