Work on typing

[lgpl/argeo-commons.git] / org.argeo.api / src / org / argeo / api / gcr / Content.java

diff --git a/org.argeo.api/src/org/argeo/api/gcr/Content.java b/org.argeo.api/src/org/argeo/api/gcr/Content.java
index e35f42f27ab7519d1122790b009ac3b65121d6ff..fa4d5071330d87f08b3eca2c984a9ee0e229c3b4 100644 (file)
--- a/org.argeo.api/src/org/argeo/api/gcr/Content.java
+++ b/org.argeo.api/src/org/argeo/api/gcr/Content.java
@@ -1,6 +1,8 @@
 package org.argeo.api.gcr;
 
+import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 
 import javax.xml.XMLConstants;
 import javax.xml.namespace.QName;
@@ -20,7 +22,7 @@ public interface Content extends Iterable<Content>, Map<QName, Object> {
         * ATTRIBUTES OPERATIONS
         */
 
-       <A> A get(QName key, Class<A> clss) throws IllegalArgumentException;
+       <A> Optional<A> get(QName key, Class<A> clss);
 
        default Object get(String key) {
                if (key.indexOf(':') >= 0)
@@ -40,6 +42,29 @@ public interface Content extends Iterable<Content>, Map<QName, Object> {
                return remove(new QName(XMLConstants.NULL_NS_URI, key, XMLConstants.DEFAULT_NS_PREFIX));
        }
 
+       Class<?> getType(QName key);
+
+       boolean isMultiple(QName key);
+
+       <A> Optional<List<A>> getMultiple(QName key, Class<A> clss);
+
+       default <A> List<A> getMultiple(QName key) {
+               Class<A> type;
+               try {
+                       type = (Class<A>) getType(key);
+               } catch (ClassCastException e) {
+                       throw new IllegalArgumentException("Requested type is not the default type");
+               }
+               Optional<List<A>> res = getMultiple(key, type);
+               if (res == null)
+                       return null;
+               else {
+                       if (res.isEmpty())
+                               throw new IllegalStateException("Metadata " + key + " is not availabel as list of type " + type);
+                       return res.get();
+               }
+       }
+
        /*
         * CONTENT OPERATIONS
         */