diff --git a/config/src/main/java/com/typesafe/config/Optional.java b/config/src/main/java/com/typesafe/config/Optional.java
new file mode 100644
index 00000000..4645ed5f
--- /dev/null
+++ b/config/src/main/java/com/typesafe/config/Optional.java
@@ -0,0 +1,14 @@
+package com.typesafe.config;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/**
+ * Allows an config property to be {@code null}.
+ */
+@Documented
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Optional {
+
+}
diff --git a/config/src/main/java/com/typesafe/config/impl/ConfigBeanImpl.java b/config/src/main/java/com/typesafe/config/impl/ConfigBeanImpl.java
index 6f425a95..e794132e 100644
--- a/config/src/main/java/com/typesafe/config/impl/ConfigBeanImpl.java
+++ b/config/src/main/java/com/typesafe/config/impl/ConfigBeanImpl.java
@@ -4,6 +4,7 @@ import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
+import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
@@ -21,6 +22,7 @@ import com.typesafe.config.ConfigException;
import com.typesafe.config.ConfigMemorySize;
import com.typesafe.config.ConfigValue;
import com.typesafe.config.ConfigValueType;
+import com.typesafe.config.Optional;
/**
* Internal implementation detail, not ABI stable, do not touch.
@@ -90,7 +92,9 @@ public class ConfigBeanImpl {
if (configValue != null) {
SimpleConfig.checkValid(path, expectedType, configValue, problems);
} else {
- SimpleConfig.addMissing(problems, expectedType, path, config.origin());
+ if (!isOptionalProperty(clazz, beanProp)) {
+ SimpleConfig.addMissing(problems, expectedType, path, config.origin());
+ }
}
}
}
@@ -105,7 +109,17 @@ public class ConfigBeanImpl {
Method setter = beanProp.getWriteMethod();
Type parameterType = setter.getGenericParameterTypes()[0];
Class<?> parameterClass = setter.getParameterTypes()[0];
- Object unwrapped = getValue(clazz, parameterType, parameterClass, config, originalNames.get(beanProp.getName()));
+ String configPropName = originalNames.get(beanProp.getName());
+ // Is the property key missing in the config?
+ if (configPropName == null) {
+ // If so, continue if the field is marked as @{link Optional}
+ if (isOptionalProperty(clazz, beanProp)) {
+ continue;
+ }
+ // Otherwise, raise a {@link Missing} exception right here
+ throw new ConfigException.Missing(beanProp.getName());
+ }
+ Object unwrapped = getValue(clazz, parameterType, parameterClass, config, configPropName);
setter.invoke(bean, unwrapped);
}
return bean;
@@ -252,4 +266,24 @@ public class ConfigBeanImpl {
return false;
}
+
+ private static boolean isOptionalProperty(Class beanClass, PropertyDescriptor beanProp) {
+ Field field = getField(beanClass, beanProp.getName());
+ return (field.getAnnotationsByType(Optional.class).length > 0);
+ }
+
+ private static Field getField(Class beanClass, String fieldName) {
+ try {
+ Field field = beanClass.getDeclaredField(fieldName);
+ field.setAccessible(true);
+ return field;
+ } catch (NoSuchFieldException e) {
+ // Don't give up yet. Try to look for field in super class, if any.
+ }
+ beanClass = beanClass.getSuperclass();
+ if (beanClass == null) {
+ return null;
+ }
+ return getField(beanClass, fieldName);
+ }
}
diff --git a/config/src/test/java/beanconfig/ObjectsConfig.java b/config/src/test/java/beanconfig/ObjectsConfig.java
new file mode 100644
index 00000000..f3009c96
--- /dev/null
+++ b/config/src/test/java/beanconfig/ObjectsConfig.java
@@ -0,0 +1,68 @@
+package beanconfig;
+
+
+import com.typesafe.config.Optional;
+
+public class ObjectsConfig {
+ public static class ValueObject {
+ @Optional
+ private String optionalValue;
+ private String mandatoryValue;
+
+ public String getMandatoryValue() {
+ return mandatoryValue;
+ }
+
+ public void setMandatoryValue(String mandatoryValue) {
+ this.mandatoryValue = mandatoryValue;
+ }
+
+ public String getOptionalValue() {
+ return optionalValue;
+ }
+
+ public void setOptionalValue(String optionalValue) {
+ this.optionalValue = optionalValue;
+ }
+ }
+
+ private ValueObject valueObject;
+
+ public ValueObject getValueObject() {
+
+ return valueObject;
+ }
+
+ public void setValueObject(ValueObject valueObject) {
+ this.valueObject = valueObject;
+ }
+
+ @Override
+ public boolean equals(Object o) {
+ if (this == o) {
+ return true;
+ }
+ if (!(o instanceof ObjectsConfig)) {
+ return false;
+ }
+
+ ObjectsConfig that = (ObjectsConfig) o;
+
+ return !(getValueObject() != null ? !getValueObject().equals(that.getValueObject()) : that.getValueObject() != null);
+
+ }
+
+ @Override
+ public int hashCode() {
+ return getValueObject() != null ? getValueObject().hashCode() : 0;
+ }
+
+
+ @Override
+ public String toString() {
+ final StringBuffer sb = new StringBuffer("ObjectsConfig{");
+ sb.append("innerType=").append(valueObject);
+ sb.append('}');
+ return sb.toString();
+ }
+}
diff --git a/config/src/test/resources/beanconfig/beanconfig01.conf b/config/src/test/resources/beanconfig/beanconfig01.conf
index 11adc078..fae411af 100644
--- a/config/src/test/resources/beanconfig/beanconfig01.conf
+++ b/config/src/test/resources/beanconfig/beanconfig01.conf
@@ -92,5 +92,10 @@
"configValue" : "hello world",
"list" : [1,2,3],
"unwrappedMap" : ${validation}
+ },
+ "objects" : {
+ "valueObject": {
+ "mandatoryValue": "notNull"
+ }
}
}
diff --git a/config/src/test/scala/com/typesafe/config/impl/ConfigBeanFactoryTest.scala b/config/src/test/scala/com/typesafe/config/impl/ConfigBeanFactoryTest.scala
index 64b3f0c4..755ab2ae 100644
--- a/config/src/test/scala/com/typesafe/config/impl/ConfigBeanFactoryTest.scala
+++ b/config/src/test/scala/com/typesafe/config/impl/ConfigBeanFactoryTest.scala
@@ -162,6 +162,25 @@ class ConfigBeanFactoryTest extends TestUtils {
assertEquals(42, beanConfig.getUnwrappedMap.get("should-be-boolean"))
}
+ @Test
+ def testOptionalProperties() {
+ val beanConfig: ObjectsConfig = ConfigBeanFactory.create(loadConfig().getConfig("objects"), classOf[ObjectsConfig])
+ assertNotNull(beanConfig)
+ assertNotNull(beanConfig.getValueObject)
+ assertNull(beanConfig.getValueObject.getOptionalValue)
+ assertEquals("notNull", beanConfig.getValueObject.getMandatoryValue)
+ }
+
+ @Test
+ def testNotAnOptionalProperty(): Unit = {
+ val e = intercept[ConfigException.ValidationFailed] {
+ ConfigBeanFactory.create(parseConfig("{valueObject: {}}"), classOf[ObjectsConfig])
+ }
+ assertTrue("missing value error", e.getMessage.contains("No setting"))
+ assertTrue("error about the right property", e.getMessage.contains("mandatoryValue"))
+
+ }
+
@Test
def testNotABeanField() {
val e = intercept[ConfigException.BadBean] {