/* * 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.klint.checks; import com.android.annotations.NonNull; import com.android.annotations.Nullable; import com.android.tools.klint.detector.api.Category; import com.android.tools.klint.detector.api.Detector; import com.android.tools.klint.detector.api.Implementation; import com.android.tools.klint.detector.api.Issue; import com.android.tools.klint.detector.api.JavaContext; import com.android.tools.klint.detector.api.Location; import com.android.tools.klint.detector.api.Scope; import com.android.tools.klint.detector.api.Severity; import com.intellij.psi.PsiMethod; import com.intellij.psi.PsiParameter; import com.intellij.psi.PsiParameterList; import com.intellij.psi.PsiType; import org.jetbrains.uast.UCallExpression; import org.jetbrains.uast.UMethod; import org.jetbrains.uast.visitor.UastVisitor; import java.util.Collections; import java.util.List; /** * Checks for errors related to Date Formats */ public class DateFormatDetector extends Detector implements Detector.UastScanner { 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 UastScanner ---- @Nullable @Override public List<String> getApplicableConstructorTypes() { return Collections.singletonList(SIMPLE_DATE_FORMAT_CLS); } @Override public void visitConstructor(@NonNull JavaContext context, @Nullable UastVisitor visitor, @NonNull UCallExpression node, @NonNull UMethod constructor) { if (!specifiesLocale(constructor)) { Location location = context.getUastLocation(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; } }