From 4512f31c698d41cdd97144187fb3ed3b94102768 Mon Sep 17 00:00:00 2001 From: Inderjeet Singh Date: Fri, 16 Sep 2016 17:35:34 -0700 Subject: [PATCH] Added PostConstruct Factory sample in Extras. --- extras/pom.xml | 21 +++-- .../PostConstructAdapterFactory.java | 76 +++++++++++++++++++ .../PostConstructAdapterFactoryTest.java | 50 ++++++++++++ 3 files changed, 139 insertions(+), 8 deletions(-) create mode 100644 extras/src/main/java/com/google/gson/typeadapters/PostConstructAdapterFactory.java create mode 100644 extras/src/test/java/com/google/gson/typeadapters/PostConstructAdapterFactoryTest.java diff --git a/extras/pom.xml b/extras/pom.xml index 41e6c9c9..1c5e76c3 100644 --- a/extras/pom.xml +++ b/extras/pom.xml @@ -40,9 +40,14 @@ com.google.code.gson gson - 2.3.1 + 2.7 compile + + javax.annotation + jsr250-api + 1.0 + junit junit @@ -86,16 +91,16 @@ org.apache.maven.plugins maven-compiler-plugin - 3.2 + 3.5.1 - 1.5 - 1.5 + 1.6 + 1.6 org.apache.maven.plugins maven-jar-plugin - 2.5 + 3.0.2 package @@ -113,7 +118,7 @@ org.apache.maven.plugins maven-source-plugin - 2.4 + 3.0.1 attach-sources @@ -127,7 +132,7 @@ org.apache.maven.plugins maven-javadoc-plugin - 2.10.1 + 2.10.4 attach-javadocs @@ -147,7 +152,7 @@ org.apache.maven.plugins maven-eclipse-plugin - 2.9 + 2.10 true true diff --git a/extras/src/main/java/com/google/gson/typeadapters/PostConstructAdapterFactory.java b/extras/src/main/java/com/google/gson/typeadapters/PostConstructAdapterFactory.java new file mode 100644 index 00000000..6d02b958 --- /dev/null +++ b/extras/src/main/java/com/google/gson/typeadapters/PostConstructAdapterFactory.java @@ -0,0 +1,76 @@ +/* + * Copyright (C) 2016 Gson Authors + * + * 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.typeadapters; + +import java.io.IOException; +import java.lang.reflect.InvocationTargetException; +import java.lang.reflect.Method; + +import javax.annotation.PostConstruct; + +import com.google.gson.Gson; +import com.google.gson.TypeAdapter; +import com.google.gson.TypeAdapterFactory; +import com.google.gson.reflect.TypeToken; +import com.google.gson.stream.JsonReader; +import com.google.gson.stream.JsonWriter; + +public class PostConstructAdapterFactory implements TypeAdapterFactory { + // copied from https://gist.github.com/swankjesse/20df26adaf639ed7fd160f145a0b661a + @Override + public TypeAdapter create(Gson gson, TypeToken type) { + for (Class t = type.getRawType(); t != Object.class; t = t.getSuperclass()) { + for (Method m : t.getDeclaredMethods()) { + if (m.isAnnotationPresent(PostConstruct.class)) { + m.setAccessible(true); + TypeAdapter delegate = gson.getDelegateAdapter(this, type); + return new PostConstructAdapter(delegate, m); + } + } + } + return null; + } + + final static class PostConstructAdapter extends TypeAdapter { + private final TypeAdapter delegate; + private final Method method; + + public PostConstructAdapter(TypeAdapter delegate, Method method) { + this.delegate = delegate; + this.method = method; + } + + @Override public T read(JsonReader in) throws IOException { + T result = delegate.read(in); + if (result != null) { + try { + method.invoke(result); + } catch (IllegalAccessException e) { + throw new AssertionError(); + } catch (InvocationTargetException e) { + if (e.getCause() instanceof RuntimeException) throw (RuntimeException) e.getCause(); + throw new RuntimeException(e.getCause()); + } + } + return result; + } + + @Override public void write(JsonWriter out, T value) throws IOException { + delegate.write(out, value); + } + } +} \ No newline at end of file diff --git a/extras/src/test/java/com/google/gson/typeadapters/PostConstructAdapterFactoryTest.java b/extras/src/test/java/com/google/gson/typeadapters/PostConstructAdapterFactoryTest.java new file mode 100644 index 00000000..1c934b11 --- /dev/null +++ b/extras/src/test/java/com/google/gson/typeadapters/PostConstructAdapterFactoryTest.java @@ -0,0 +1,50 @@ +/* + * Copyright (C) 2016 Gson Authors + * + * 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.typeadapters; + +import javax.annotation.PostConstruct; + +import com.google.gson.Gson; +import com.google.gson.GsonBuilder; + +import junit.framework.TestCase; + +public class PostConstructAdapterFactoryTest extends TestCase { + public void test() throws Exception { + Gson gson = new GsonBuilder() + .registerTypeAdapterFactory(new PostConstructAdapterFactory()) + .create(); + gson.fromJson("{\"bread\": \"white\", \"cheese\": \"cheddar\"}", Sandwich.class); + try { + gson.fromJson("{\"bread\": \"cheesey bread\", \"cheese\": \"swiss\"}", Sandwich.class); + fail(); + } catch (IllegalArgumentException expected) { + assertEquals("too cheesey", expected.getMessage()); + } + } + + static class Sandwich { + String bread; + String cheese; + + @PostConstruct void validate() { + if (bread.equals("cheesey bread") && cheese != null) { + throw new IllegalArgumentException("too cheesey"); + } + } + } +}