Add a way of constructing OptionsBase subclass instances from maps
Added toMap()/fromMap() to OptionsParser, and moved the implementation of OptionsBase#asMap away from OptionsParserImpl.
RELNOTES: None
PiperOrigin-RevId: 153602479
diff --git a/src/main/java/com/google/devtools/common/options/OptionsBase.java b/src/main/java/com/google/devtools/common/options/OptionsBase.java
index 0ca9e44..48658f7 100644
--- a/src/main/java/com/google/devtools/common/options/OptionsBase.java
+++ b/src/main/java/com/google/devtools/common/options/OptionsBase.java
@@ -16,15 +16,15 @@
import com.google.common.escape.CharEscaperBuilder;
import com.google.common.escape.Escaper;
-
+import java.lang.reflect.Field;
+import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
/**
- * Base class for all options classes. Extend this class, adding public
- * instance fields annotated with @Option. Then you can create instances
- * either programmatically:
+ * Base class for all options classes. Extend this class, adding public instance fields annotated
+ * with {@link Option}. Then you can create instances either programmatically:
*
* <pre>
* X x = Options.getDefaults(X.class);
@@ -40,11 +40,10 @@
* X x = parser.getOptions(X.class);
* </pre>
*
- * <p>Subclasses of OptionsBase <b>must</b> be constructed reflectively,
- * i.e. using not {@code new MyOptions}, but one of the two methods above
- * instead. (Direct construction creates an empty instance, not containing
- * default values. This leads to surprising behavior and often
- * NullPointerExceptions, etc.)
+ * <p>Subclasses of {@code OptionsBase} <i>must</i> be constructed reflectively, i.e. using not
+ * {@code new MyOptions()}, but one of the above methods instead. (Direct construction creates an
+ * empty instance, not containing default values. This leads to surprising behavior and often {@code
+ * NullPointerExceptions}, etc.)
*/
public abstract class OptionsBase {
@@ -61,13 +60,24 @@
}
/**
- * Returns this options object in the form of a (new) mapping from option
- * names, including inherited ones, to option values. If the public fields
- * are mutated, this will be reflected in subsequent calls to {@code asMap}.
- * Mutation of this map by the caller does not affect this options object.
+ * Returns a mapping from option names to values, for each option on this object, including
+ * inherited ones. The mapping is a copy, so subsequent mutations to it or to this object are
+ * independent. Entries are sorted alphabetically.
*/
- public final Map<String, Object> asMap() {
- return OptionsParserImpl.optionsAsMap(this);
+ public final <O extends OptionsBase> Map<String, Object> asMap() {
+ // Generic O is needed to tell the type system that the toMap() call is safe.
+ // The casts are safe because this <= O <= OptionsBase.
+ @SuppressWarnings("unchecked")
+ O castThis = (O) this;
+ @SuppressWarnings("unchecked")
+ Class<O> castClass = (Class<O>) getClass();
+
+ Map<String, Object> map = new LinkedHashMap<>();
+ for (Map.Entry<Field, Object> entry : OptionsParser.toMap(castClass, castThis).entrySet()) {
+ String name = entry.getKey().getAnnotation(Option.class).name();
+ map.put(name, entry.getValue());
+ }
+ return map;
}
@Override
