X-Git-Url: http://git.ieval.ro/?a=blobdiff_plain;f=src%2Fcom%2Fgoogle%2Fgson%2FExclusionStrategy.java;fp=src%2Fcom%2Fgoogle%2Fgson%2FExclusionStrategy.java;h=08fafedfa9bf625efd575180fcc6728c401e70a6;hb=cfd903b6b5113fa28991db19bf98d0340ae709a4;hp=0000000000000000000000000000000000000000;hpb=819197b2305a94ab4924c5ae37a3fad762078448;p=unical.git diff --git a/src/com/google/gson/ExclusionStrategy.java b/src/com/google/gson/ExclusionStrategy.java new file mode 100644 index 0000000..08fafed --- /dev/null +++ b/src/com/google/gson/ExclusionStrategy.java @@ -0,0 +1,109 @@ +/* + * Copyright (C) 2008 Google Inc. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package com.google.gson; + +/** + * A strategy (or policy) definition that is used to decide whether or not a field or top-level + * class should be serialized or deserialized as part of the JSON output/input. For serialization, + * if the {@link #shouldSkipClass(Class)} method returns false then that class or field type + * will not be part of the JSON output. For deserialization, if {@link #shouldSkipClass(Class)} + * returns false, then it will not be set as part of the Java object structure. + * + *

The following are a few examples that shows how you can use this exclusion mechanism. + * + *

Exclude fields and objects based on a particular class type: + * 

+ * private static class SpecificClassExclusionStrategy implements ExclusionStrategy {
+ *   private final Class<?> excludedThisClass;
+ *
+ *   public SpecificClassExclusionStrategy(Class<?> excludedThisClass) {
+ *     this.excludedThisClass = excludedThisClass;
+ *   }
+ *
+ *   public boolean shouldSkipClass(Class<?> clazz) {
+ *     return excludedThisClass.equals(clazz);
+ *   }
+ *
+ *   public boolean shouldSkipField(FieldAttributes f) {
+ *     return excludedThisClass.equals(f.getDeclaredClass());
+ *   }
+ * }
+ *
+ * + *

Excludes fields and objects based on a particular annotation: + * 

+ * public @interface FooAnnotation {
+ *   // some implementation here
+ * }
+ *
+ * // Excludes any field (or class) that is tagged with an "@FooAnnotation"
+ * private static class FooAnnotationExclusionStrategy implements ExclusionStrategy {
+ *   public boolean shouldSkipClass(Class<?> clazz) {
+ *     return clazz.getAnnotation(FooAnnotation.class) != null;
+ *   }
+ *
+ *   public boolean shouldSkipField(FieldAttributes f) {
+ *     return f.getAnnotation(FooAnnotation.class) != null;
+ *   }
+ * }
+ *
+ * + *

Now if you want to configure {@code Gson} to use a user defined exclusion strategy, then + * the {@code GsonBuilder} is required. The following is an example of how you can use the + * {@code GsonBuilder} to configure Gson to use one of the above sample: + * 

+ * ExclusionStrategy excludeStrings = new UserDefinedExclusionStrategy(String.class);
+ * Gson gson = new GsonBuilder()
+ *     .setExclusionStrategies(excludeStrings)
+ *     .create();
+ *
+ * + *

For certain model classes, you may only want to serialize a field, but exclude it for + * deserialization. To do that, you can write an {@code ExclusionStrategy} as per normal; + * however, you would register it with the + * {@link GsonBuilder#addDeserializationExclusionStrategy(ExclusionStrategy)} method. + * For example: + * 

+ * ExclusionStrategy excludeStrings = new UserDefinedExclusionStrategy(String.class);
+ * Gson gson = new GsonBuilder()
+ *     .addDeserializationExclusionStrategy(excludeStrings)
+ *     .create();
+ *
+ * + * @author Inderjeet Singh + * @author Joel Leitch + * + * @see GsonBuilder#setExclusionStrategies(ExclusionStrategy...) + * @see GsonBuilder#addDeserializationExclusionStrategy(ExclusionStrategy) + * @see GsonBuilder#addSerializationExclusionStrategy(ExclusionStrategy) + * + * @since 1.4 + */ +public interface ExclusionStrategy { + + /** + * @param f the field object that is under test + * @return true if the field should be ignored; otherwise false + */ + public boolean shouldSkipField(FieldAttributes f); + + /** + * @param clazz the class object that is under test + * @return true if the class should be ignored; otherwise false + */ + public boolean shouldSkipClass(Class clazz); +}