/*
* Copyright 2017 Google Inc. All Rights Reserved.
*
* 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.errorprone.bugpatterns;
import static com.google.errorprone.BugPattern.Category.JDK;
import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
import com.google.common.collect.ImmutableSet;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.matchers.Matchers;
import com.google.errorprone.matchers.method.MethodMatchers;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.MethodInvocationTree;
import java.util.TimeZone;
import java.util.regex.Pattern;
/** @author awturner@google.com (Andy Turner) */
@BugPattern(
name = "InvalidTimeZoneID",
summary =
"Invalid time zone identifier. TimeZone.getTimeZone(String) will silently return GMT instead "
+ "of the time zone you intended.",
explanation =
"TimeZone.getTimeZone(String) silently returns GMT when an invalid time zone identifier is "
+ "passed in.",
category = JDK,
severity = ERROR
)
public class InvalidTimeZoneID extends BugChecker implements MethodInvocationTreeMatcher {
private static final ImmutableSet<String> AVAILABLE_IDS =
ImmutableSet.copyOf(TimeZone.getAvailableIDs());
private static final Matcher<ExpressionTree> METHOD_MATCHER =
Matchers.methodInvocation(
MethodMatchers.staticMethod()
.onClass("java.util.TimeZone")
.withSignature("getTimeZone(java.lang.String)"));
// https://docs.oracle.com/javase/8/docs/api/java/util/TimeZone.html
// "a custom time zone ID can be specified to produce a TimeZone".
// 0-23, with optional leading zero.
private static final String HOURS_PATTERN = "([0-9]|[0-1][0-9]|2[0-3])";
// 00-59, optional.
private static final String MINUTES_PATTERN = "(?:[0-5][0-9])?";
private static final Pattern CUSTOM_ID_PATTERN =
Pattern.compile("GMT[+\\-]" + HOURS_PATTERN + ":?" + MINUTES_PATTERN);
@Override
public Description matchMethodInvocation(MethodInvocationTree tree, final VisitorState state) {
if (!METHOD_MATCHER.matches(tree, state)) {
return Description.NO_MATCH;
}
String value = (String) ASTHelpers.constValue(tree.getArguments().get(0));
if (value == null) {
// Value isn't a compile-time constant, so we can't know if it's unsafe.
return Description.NO_MATCH;
}
if (isValidID(value)) {
// Value is supported on this JVM.
return Description.NO_MATCH;
}
// Value is invalid, so let's suggest some alternatives.
Description.Builder builder = buildDescription(tree);
// Try to see if it's just been mistyped with spaces instead of underscores - if so, offer this
// as a potential fix.
String spacesToUnderscores = value.replace(' ', '_');
if (isValidID(spacesToUnderscores)) {
builder.addFix(
SuggestedFix.replace(
tree.getArguments().get(0), String.format("\"%s\"", spacesToUnderscores)));
}
return builder.build();
}
private static boolean isValidID(String value) {
if (AVAILABLE_IDS.contains(value)) {
// Value is in TimeZone.getAvailableIDs(), so it's supported on this JVM.
return true;
}
if (CUSTOM_ID_PATTERN.matcher(value).matches()) {
// Value is a custom ID, so it's supported.
return true;
}
return false;
}
}