com.google.inject.internal.util.SourceProvider Maven / Gradle / Ivy
/*
* Copyright (C) 2006 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.inject.internal.util;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Lists;
import java.util.List;
/**
* Provides access to the calling line of code.
*
* @author [email protected] (Bob Lee)
*/
public final class SourceProvider {
/** Indicates that the source is unknown. */
public static final Object UNKNOWN_SOURCE = "[unknown source]";
private final SourceProvider parent;
private final ImmutableSet classNamesToSkip;
public static final SourceProvider DEFAULT_INSTANCE =
new SourceProvider(ImmutableSet.of(SourceProvider.class.getName()));
private SourceProvider(Iterable classesToSkip) {
this(null, classesToSkip);
}
private SourceProvider(SourceProvider parent, Iterable classesToSkip) {
this.parent = parent;
ImmutableSet.Builder classNamesToSkipBuilder = ImmutableSet.builder();
for (String classToSkip : classesToSkip) {
if (parent == null || !parent.shouldBeSkipped(classToSkip)) {
classNamesToSkipBuilder.add(classToSkip);
}
}
this.classNamesToSkip = classNamesToSkipBuilder.build();
}
/** Returns a new instance that also skips {@code moreClassesToSkip}. */
public SourceProvider plusSkippedClasses(Class... moreClassesToSkip) {
return new SourceProvider(this, asStrings(moreClassesToSkip));
}
/** Returns true if the className should be skipped. */
private boolean shouldBeSkipped(String className) {
return (parent != null && parent.shouldBeSkipped(className))
|| classNamesToSkip.contains(className);
}
/** Returns the class names as Strings */
private static List asStrings(Class... classes) {
List strings = Lists.newArrayList();
for (Class c : classes) {
strings.add(c.getName());
}
return strings;
}
/**
* Returns the calling line of code. The selected line is the nearest to the top of the stack that
* is not skipped.
*/
public StackTraceElement get(StackTraceElement[] stackTraceElements) {
Preconditions.checkNotNull(stackTraceElements, "The stack trace elements cannot be null.");
for (final StackTraceElement element : stackTraceElements) {
String className = element.getClassName();
if (!shouldBeSkipped(className)) {
return element;
}
}
throw new AssertionError();
}
/** Returns the non-skipped module class name. */
public Object getFromClassNames(List moduleClassNames) {
Preconditions.checkNotNull(moduleClassNames, "The list of module class names cannot be null.");
for (final String moduleClassName : moduleClassNames) {
if (!shouldBeSkipped(moduleClassName)) {
return new StackTraceElement(moduleClassName, "configure", null, -1);
}
}
return UNKNOWN_SOURCE;
}
}