/*
* Copyright 2012-2017 the original author or 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 org.springframework.boot.test.json;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ObjectReader;
import com.fasterxml.jackson.databind.ObjectWriter;
import org.springframework.beans.factory.ObjectFactory;
import org.springframework.core.ResolvableType;
import org.springframework.util.Assert;
/**
* AssertJ based JSON tester backed by Jackson. Usually instantiated via
* {@link #initFields(Object, ObjectMapper)}, for example: <pre class="code">
* public class ExampleObjectJsonTests {
*
* private JacksonTester<ExampleObject> json;
*
* @Before
* public void setup() {
* ObjectMapper objectMapper = new ObjectMapper();
* JacksonTester.initFields(this, objectMapper);
* }
*
* @Test
* public void testWriteJson() throws IOException {
* ExampleObject object = //...
* assertThat(json.write(object)).isEqualToJson("expected.json");
* }
*
* }
* </pre>
*
* See {@link AbstractJsonMarshalTester} for more details.
*
* @param <T> the type under test
* @author Phillip Webb
* @author Madhura Bhave
* @since 1.4.0
*/
public class JacksonTester<T> extends AbstractJsonMarshalTester<T> {
private final ObjectMapper objectMapper;
private Class<?> view;
/**
* Create a new {@link JacksonTester} instance.
* @param objectMapper the Jackson object mapper
*/
protected JacksonTester(ObjectMapper objectMapper) {
Assert.notNull(objectMapper, "ObjectMapper must not be null");
this.objectMapper = objectMapper;
}
/**
* Create a new {@link JacksonTester} instance.
* @param resourceLoadClass the source class used to load resources
* @param type the type under test
* @param objectMapper the Jackson object mapper
*/
public JacksonTester(Class<?> resourceLoadClass, ResolvableType type,
ObjectMapper objectMapper) {
this(resourceLoadClass, type, objectMapper, null);
}
public JacksonTester(Class<?> resourceLoadClass, ResolvableType type,
ObjectMapper objectMapper, Class<?> view) {
super(resourceLoadClass, type);
Assert.notNull(objectMapper, "ObjectMapper must not be null");
this.objectMapper = objectMapper;
this.view = view;
}
@Override
protected T readObject(InputStream inputStream, ResolvableType type)
throws IOException {
return getObjectReader(type).readValue(inputStream);
}
@Override
protected T readObject(Reader reader, ResolvableType type) throws IOException {
return getObjectReader(type).readValue(reader);
}
private ObjectReader getObjectReader(ResolvableType type) {
ObjectReader objectReader = this.objectMapper.readerFor(getType(type));
if (this.view != null) {
return objectReader.withView(this.view);
}
return objectReader;
}
@Override
protected String writeObject(T value, ResolvableType type) throws IOException {
return getObjectWriter(type).writeValueAsString(value);
}
private ObjectWriter getObjectWriter(ResolvableType type) {
ObjectWriter objectWriter = this.objectMapper.writerFor(getType(type));
if (this.view != null) {
return objectWriter.withView(this.view);
}
return objectWriter;
}
private JavaType getType(ResolvableType type) {
return this.objectMapper.constructType(type.getType());
}
/**
* Utility method to initialize {@link JacksonTester} fields. See {@link JacksonTester
* class-level documentation} for example usage.
* @param testInstance the test instance
* @param objectMapper the object mapper
* @see #initFields(Object, ObjectMapper)
*/
public static void initFields(Object testInstance, ObjectMapper objectMapper) {
new JacksonFieldInitializer().initFields(testInstance, objectMapper);
}
/**
* Utility method to initialize {@link JacksonTester} fields. See {@link JacksonTester
* class-level documentation} for example usage.
* @param testInstance the test instance
* @param objectMapperFactory a factory to create the object mapper
* @see #initFields(Object, ObjectMapper)
*/
public static void initFields(Object testInstance,
ObjectFactory<ObjectMapper> objectMapperFactory) {
new JacksonFieldInitializer().initFields(testInstance, objectMapperFactory);
}
/**
* Returns a new instance of {@link JacksonTester} with the view that should be used
* for json serialization/deserialization.
* @param view the view class
* @return the new instance
*/
public JacksonTester<T> forView(Class<?> view) {
return new JacksonTester<T>(this.getResourceLoadClass(), this.getType(),
this.objectMapper, view);
}
/**
* {@link FieldInitializer} for Jackson.
*/
private static class JacksonFieldInitializer extends FieldInitializer<ObjectMapper> {
protected JacksonFieldInitializer() {
super(JacksonTester.class);
}
@Override
protected AbstractJsonMarshalTester<Object> createTester(
Class<?> resourceLoadClass, ResolvableType type,
ObjectMapper marshaller) {
return new JacksonTester<>(resourceLoadClass, type, marshaller);
}
}
}