Return immutable lists when filtering components

ical4j · Sep 21, 2021 · 3fa847b · 3fa847b
1 parent ad2a332
commit 3fa847b
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Showing 6 changed files with 27 additions and 26 deletions.
diff --git a/src/main/java/net/fortuna/ical4j/model/ComponentContainer.java b/src/main/java/net/fortuna/ical4j/model/ComponentContainer.java
@@ -1,10 +1,12 @@
 package net.fortuna.ical4j.model;
 
+import java.util.List;
+
 public interface ComponentContainer<T extends Component> {
 
     ComponentList<T> getComponents();
 
-    default <C extends T> ComponentList<C> getComponents(final String name) {
+    default <C extends T> List<C> getComponents(final String name) {
         return getComponents().getComponents(name);
     }
 

diff --git a/src/main/java/net/fortuna/ical4j/model/ComponentList.java b/src/main/java/net/fortuna/ical4j/model/ComponentList.java
@@ -36,6 +36,7 @@
 import java.net.URISyntaxException;
 import java.text.ParseException;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -116,13 +117,13 @@ public final T getComponent(final String aName) {
      * @return a list of components with the matching name
      */
     @SuppressWarnings("unchecked")
-	public final <C extends T> ComponentList<C> getComponents(final String name) {
-        final ComponentList<C> components = new ComponentList<>();
+	public final <C extends T> List<C> getComponents(final String name) {
+        final List<C> components = new ArrayList<>();
         for (final T c : this) {
             if (c.getName().equals(name)) {
                 components.add((C) c);
             }
         }
-        return components;
+        return Collections.unmodifiableList(components);
     }
 }
diff --git a/src/main/java/net/fortuna/ical4j/model/IndexedComponentList.java b/src/main/java/net/fortuna/ical4j/model/IndexedComponentList.java
@@ -31,9 +31,7 @@
  */
 package net.fortuna.ical4j.model;
 
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
+import java.util.*;
 
 /**
  * $Id$
@@ -45,27 +43,26 @@
  */
 public class IndexedComponentList<T extends Component> {
 
-    private final ComponentList<T> EMPTY_LIST = new ComponentList<T>();
-
-    private Map<String, ComponentList<T>> index;
+    private Map<String, List<T>> index;
 
     /**
      * Creates a new instance indexed on properties with the specified name.
      * @param list a list of components
      * @param propertyName the name of the properties to index on
      */
-    public IndexedComponentList(final ComponentList<T> list, final String propertyName) {
-        final Map<String, ComponentList<T>> indexedComponents = new HashMap<String, ComponentList<T>>();
+    public IndexedComponentList(final List<T> list, final String propertyName) {
+        final Map<String, List<T>> indexedComponents = new HashMap<>();
         for (final T component : list) {
             for (final Property property : component.getProperties(propertyName)) {
-                ComponentList<T> components = indexedComponents.get(property.getValue());
+                List<T> components = indexedComponents.get(property.getValue());
                 if (components == null) {
-                    components = new ComponentList<T>();
+                    components = new ArrayList<>();
                     indexedComponents.put(property.getValue(), components);
                 }
                 components.add(component);
             }
         }
+        indexedComponents.keySet().forEach(p -> indexedComponents.put(p, Collections.unmodifiableList(indexedComponents.get(p))));
         this.index = Collections.unmodifiableMap(indexedComponents);
     }
 
@@ -76,10 +73,10 @@ public IndexedComponentList(final ComponentList<T> list, final String propertyNa
      * returned components
      * @return a component list
      */
-    public ComponentList<T> getComponents(final String propertyValue) {
-        ComponentList<T> components = index.get(propertyValue);
+    public List<T> getComponents(final String propertyValue) {
+        List<T> components = index.get(propertyValue);
         if (components == null) {
-            components = EMPTY_LIST;
+            components = Collections.EMPTY_LIST;
         }
         return components;
     }
@@ -93,7 +90,7 @@ public ComponentList<T> getComponents(final String propertyValue) {
      * with the specified value
      */
     public T getComponent(final String propertyValue) {
-        final ComponentList<T> components = getComponents(propertyValue);
+        final List<T> components = getComponents(propertyValue);
         if (!components.isEmpty()) {
             return components.get(0);
         }

diff --git a/src/main/java/net/fortuna/ical4j/model/TimeZone.java b/src/main/java/net/fortuna/ical4j/model/TimeZone.java
@@ -41,6 +41,7 @@
 
 import java.util.Calendar;
 import java.util.Date;
+import java.util.List;
 
 /**
  * $Id$
@@ -157,7 +158,7 @@ public final void setRawOffset(final int offsetMillis) {
      */
     @Override
     public final boolean useDaylightTime() {
-        final ComponentList<Observance> daylights = vTimeZone.getObservances().getComponents(Observance.DAYLIGHT);
+        final List<Observance> daylights = vTimeZone.getObservances().getComponents(Observance.DAYLIGHT);
         return (!daylights.isEmpty());
     }
 
@@ -170,7 +171,7 @@ public final VTimeZone getVTimeZone() {
 
     private static int getRawOffset(VTimeZone vt) {
 
-        ComponentList<Observance> seasonalTimes = vt.getObservances().getComponents(Observance.STANDARD);
+        List<Observance> seasonalTimes = vt.getObservances().getComponents(Observance.STANDARD);
         // if no standard time use daylight time..
         if (seasonalTimes.isEmpty()) {
             seasonalTimes = vt.getObservances().getComponents(Observance.DAYLIGHT);

diff --git a/src/main/java/net/fortuna/ical4j/util/Calendars.java b/src/main/java/net/fortuna/ical4j/util/Calendars.java
@@ -47,6 +47,7 @@
 import java.nio.file.Paths;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -137,9 +138,8 @@ public static Calendar[] split(final Calendar calendar) {
             return new Calendar[] {calendar};
         }
 
-        final ComponentList<VTimeZone> timezoneList = calendar.getComponents(Component.VTIMEZONE);
-		final IndexedComponentList<VTimeZone> timezones = new IndexedComponentList<VTimeZone>(
-        		timezoneList, Property.TZID);
+        final List<VTimeZone> timezoneList = calendar.getComponents(Component.VTIMEZONE);
+		final IndexedComponentList<VTimeZone> timezones = new IndexedComponentList<>(timezoneList, Property.TZID);
 
         final Map<Uid, Calendar> calendars = new HashMap<Uid, Calendar>();
         for (final CalendarComponent c : calendar.getComponents()) {

diff --git a/src/test/java/net/fortuna/ical4j/data/CalendarBuilderTimezoneTest.java b/src/test/java/net/fortuna/ical4j/data/CalendarBuilderTimezoneTest.java
@@ -34,7 +34,6 @@
 import junit.framework.TestCase;
 import net.fortuna.ical4j.model.Calendar;
 import net.fortuna.ical4j.model.Component;
-import net.fortuna.ical4j.model.ComponentList;
 import net.fortuna.ical4j.model.DateTime;
 import net.fortuna.ical4j.model.component.CalendarComponent;
 import net.fortuna.ical4j.model.component.VEvent;
@@ -45,6 +44,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.StringReader;
+import java.util.List;
 
 /**
  * $Id: CalendarBuilderTimezoneTest.java [Jul 1, 2008]
@@ -98,7 +98,7 @@ public void testVTimeZoneAfterVEvent() throws Exception {
 
         calendar = builder.build(in);
         assertNotNull("Calendar is null", calendar);
-        ComponentList<CalendarComponent> comps = calendar.getComponents(Component.VEVENT);
+        List<CalendarComponent> comps = calendar.getComponents(Component.VEVENT);
         assertTrue("VEVENT not found", comps.size() == 1);
         VEvent vevent = (VEvent) comps.get(0);
 
@@ -176,7 +176,7 @@ public void testTwoDaylights() throws IOException, ParserException {
 
         calendar = builder.build(in);
         assertNotNull("Calendar is null", calendar);
-        ComponentList<CalendarComponent> comps = calendar.getComponents(Component.VEVENT);
+        List<CalendarComponent> comps = calendar.getComponents(Component.VEVENT);
         assertEquals("2 VEVENTs not found", 2, comps.size());
         VEvent vevent0 = (VEvent) comps.get(0);