Author: limpbizkit
Date: Thu May 7 12:15:22 2009
New Revision: 941
Modified:
trunk/src/com/google/inject/TypeLiteral.java
trunk/src/com/google/inject/util/Types.java
Log:
additional doc for TypeLiteral, helping to make it easier to find wildcard
types.
Modified: trunk/src/com/google/inject/TypeLiteral.java
==============================================================================
--- trunk/src/com/google/inject/TypeLiteral.java (original)
+++ trunk/src/com/google/inject/TypeLiteral.java Thu May 7 12:15:22 2009
@@ -45,8 +45,21 @@
* <p>
* {...@code TypeLiteral<List<String>> list = new TypeLiteral<List<String>>()
{};}
*
- * <p>Assumes that type {...@code T} implements {...@link Object#equals} and
- * {...@link Object#hashCode()} as value (as opposed to identity) comparison.
+ * <p>This syntax cannot be used to create type literals that have wildcard
+ * parameters, such as {...@code Class<?>} or {...@code List<? extends
CharSequence>}.
+ * Such type literals must be constructed programatically, either by {...@link
+ * Method#getGenericReturnType extracting types from members} or by using
the
+ * {...@link Types} factory class.
+ *
+ * <p>Along with modeling generic types, this class can resolve type
parameters.
+ * For example, to figure out what type {...@code keySet()} returns on a
{...@code
+ * Map<Integer, String>}, use this code:<pre> {...@code
+ *
+ * TypeLiteral<Map<Integer, String>> mapType
+ * = new TypeLiteral<Map<Integer, String>>() {};
+ * TypeLiteral<?> keySetType
+ * = mapType.getReturnType(Map.class.getMethod("keySet"));
+ * System.out.println(keySetType); // prints "Set<Integer>"}</pre>
*
* @author [email protected] (Bob Lee)
* @author [email protected] (Jesse Wilson)
Modified: trunk/src/com/google/inject/util/Types.java
==============================================================================
--- trunk/src/com/google/inject/util/Types.java (original)
+++ trunk/src/com/google/inject/util/Types.java Thu May 7 12:15:22 2009
@@ -72,13 +72,18 @@
/**
* Returns a type that represents an unknown type that extends {...@code
bound}.
+ * For example, if {...@code bound} is {...@code CharSequence.class}, this
returns
+ * {...@code ? extends CharSequence}. If {...@code bound} is {...@code
Object.class},
+ * this returns {...@code ?}, which is shorthand for {...@code ? extends
Object}.
*/
public static WildcardType subtypeOf(Type bound) {
return new WildcardTypeImpl(new Type[] { bound },
MoreTypes.EMPTY_TYPE_ARRAY);
}
/**
- * Returns a type that represents an unknown supertype of {...@code bound}.
+ * Returns a type that represents an unknown supertype of {...@code bound}.
For
+ * example, if {...@code bound} is {...@code String.class}, this returns
{...@code ?
+ * super String}.
*/
public static WildcardType supertypeOf(Type bound) {
return new WildcardTypeImpl(new Type[] { Object.class }, new Type[] {
bound });
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