Merge pull request #1582 from swtseaman/master

- add： Value注解增加默认值支持

Author: wendal

src/org/nutz/ioc/loader/annotation/AnnotationIocLoader.java

@@ -167,7 +167,13 @@ public void addClass(Class<?> classZ) {
                 } else {
                     configName = value.name();
                 }
-                IocValue iocValue = Iocs.convert(String.format("java:$conf.get('%s')", configName), true);
+                String defaultValue = value.defaultValue();
+                IocValue iocValue;
+                if(Strings.isBlank(defaultValue)) {
+                    iocValue = Iocs.convert(String.format("java:$conf.get('%s')", configName), true);
+                } else {
+                    iocValue = Iocs.convert(String.format("java:$conf.get('%s', '%s')", configName, defaultValue), true);
+                }
                 IocField iocField = new IocField();
                 iocField.setName(valueField.getName());
                 iocField.setValue(iocValue);

src/org/nutz/ioc/loader/annotation/Value.java

@@ -17,4 +17,10 @@
      * @return
      */
     String name() default "";
+
+    /**
+     * 配置项默认值
+     * @return
+     */
+    String defaultValue() default "";
 }