com.android.tools.lint.checks.DateFormatDetector Maven / Gradle / Ivy
/*
* Copyright (C) 2014 The Android Open Source Project
*
* 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.android.tools.lint.checks;
import com.android.annotations.NonNull;
import com.android.annotations.Nullable;
import com.android.tools.lint.detector.api.Category;
import com.android.tools.lint.detector.api.Detector;
import com.android.tools.lint.detector.api.Implementation;
import com.android.tools.lint.detector.api.Issue;
import com.android.tools.lint.detector.api.JavaContext;
import com.android.tools.lint.detector.api.Location;
import com.android.tools.lint.detector.api.Scope;
import com.android.tools.lint.detector.api.Severity;
import com.intellij.psi.JavaElementVisitor;
import com.intellij.psi.PsiMethod;
import com.intellij.psi.PsiNewExpression;
import com.intellij.psi.PsiParameter;
import com.intellij.psi.PsiParameterList;
import com.intellij.psi.PsiType;
import java.util.Collections;
import java.util.List;
/**
* Checks for errors related to Date Formats
*/
public class DateFormatDetector extends Detector implements Detector.JavaPsiScanner {
private static final Implementation IMPLEMENTATION = new Implementation(
DateFormatDetector.class,
Scope.JAVA_FILE_SCOPE);
/** Constructing SimpleDateFormat without an explicit locale */
public static final Issue DATE_FORMAT = Issue.create(
"SimpleDateFormat", //$NON-NLS-1$
"Implied locale in date format",
"Almost all callers should use `getDateInstance()`, `getDateTimeInstance()`, or " +
"`getTimeInstance()` to get a ready-made instance of SimpleDateFormat suitable " +
"for the user's locale. The main reason you'd create an instance this class " +
"directly is because you need to format/parse a specific machine-readable format, " +
"in which case you almost certainly want to explicitly ask for US to ensure that " +
"you get ASCII digits (rather than, say, Arabic digits).\n" +
"\n" +
"Therefore, you should either use the form of the SimpleDateFormat constructor " +
"where you pass in an explicit locale, such as Locale.US, or use one of the " +
"get instance methods, or suppress this error if really know what you are doing.",
Category.CORRECTNESS,
6,
Severity.WARNING,
IMPLEMENTATION)
.addMoreInfo(
"http://developer.android.com/reference/java/text/SimpleDateFormat.html");//$NON-NLS-1$
public static final String LOCALE_CLS = "java.util.Locale"; //$NON-NLS-1$
public static final String SIMPLE_DATE_FORMAT_CLS = "java.text.SimpleDateFormat"; //$NON-NLS-1$
/** Constructs a new {@link DateFormatDetector} */
public DateFormatDetector() {
}
// ---- Implements JavaScanner ----
@Nullable
@Override
public List getApplicableConstructorTypes() {
return Collections.singletonList(SIMPLE_DATE_FORMAT_CLS);
}
@Override
public void visitConstructor(@NonNull JavaContext context, @Nullable JavaElementVisitor visitor,
@NonNull PsiNewExpression node, @NonNull PsiMethod constructor) {
if (!specifiesLocale(constructor)) {
Location location = context.getLocation(node);
String message =
"To get local formatting use `getDateInstance()`, `getDateTimeInstance()`, " +
"or `getTimeInstance()`, or use `new SimpleDateFormat(String template, " +
"Locale locale)` with for example `Locale.US` for ASCII dates.";
context.report(DATE_FORMAT, node, location, message);
}
}
private static boolean specifiesLocale(@NonNull PsiMethod method) {
PsiParameterList parameterList = method.getParameterList();
PsiParameter[] parameters = parameterList.getParameters();
for (PsiParameter parameter : parameters) {
PsiType type = parameter.getType();
if (type.getCanonicalText().equals(LOCALE_CLS)) {
return true;
}
}
return false;
}
}