Replace gson mapper with jackson mapper

We introduced JsonObjectMapper (wapper) as Spring component.

Issue-ID: CPS-751

Change-Id: I536b0771a3a263325e6907717baf6941d70c0d6c
Signed-off-by: sourabh_sourabh <sourabh.sourabh@est.tech>

2 files changed, 177 insertions, 0 deletions

diff --git a/cps-service/src/main/java/org/onap/cps/utils/JsonObjectMapper.java b/cps-service/src/main/java/org/onap/cps/utils/JsonObjectMapper.java
new file mode 100644
index 0000000000..2459b51af4
--- /dev/null
+++ b/cps-service/src/main/java/org/onap/cps/utils/JsonObjectMapper.java
@@ -0,0 +1,90 @@
+/*
+ *  ============LICENSE_START=======================================================
+ *  Copyright (C) 2022 Nordix Foundation
+ *  ================================================================================
+ *  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.
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *  ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.utils;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.onap.cps.spi.exceptions.DataValidationException;
+import org.springframework.stereotype.Component;
+
+@Slf4j
+@RequiredArgsConstructor
+@Component
+public class JsonObjectMapper {
+
+    private final ObjectMapper objectMapper;
+
+    /**
+     * Serializing generic java object to JSON using Jackson.
+     *
+     * @param object any java object value
+     * @return the generated JSON as a string.
+     */
+    public String asJsonString(final Object object) {
+        try {
+            return objectMapper.writeValueAsString(object);
+        } catch (final JsonProcessingException e) {
+            log.error("Parsing error occurred while converting Object to JSON string.");
+            throw new DataValidationException("Parsing error occurred while converting given object to JSON string.",
+                    e.getMessage());
+        }
+    }
+
+    /**
+     * Constructing JavaType out of given type (typically java.lang.Class).
+     * Allow efficient value conversions for structurally compatible json objects,
+     * according to standard Jackson configuration.
+     *
+     * @param jsonObject   structurally compatible json object
+     * @param valueType compatible Object class type
+     * @param <T>         type parameter
+     * @return a class object of specific class type 'T'
+     */
+    public <T> T convertToValueType(final Object jsonObject, final Class<T> valueType) {
+        try {
+            return objectMapper.convertValue(jsonObject, valueType);
+        } catch (final IllegalArgumentException e) {
+            log.error("Found structurally incompatible object while converting into value type.");
+            throw new DataValidationException("Found structurally incompatible object while converting "
+                    + "into value type.", e.getMessage());
+        }
+    }
+
+    /**
+     * Deserialize JSON content from given JSON content String.
+     *
+     * @param jsonContent   JSON content
+     * @param valueType compatible Object class type
+     * @param <T>       type parameter
+     * @return a class object of specific class type 'T'
+     */
+    public <T> T convertJsonString(final String jsonContent, final Class<T> valueType) {
+        try {
+            return objectMapper.readValue(jsonContent, valueType);
+        } catch (final JsonProcessingException e) {
+            log.error("Parsing error occurred while converting JSON content to specific class type.");
+            throw new DataValidationException("Parsing error occurred while converting "
+                    + "JSON content to specific class type.", e.getMessage());
+        }
+    }
+}
diff --git a/cps-service/src/test/groovy/org/onap/cps/utils/JsonObjectMapperSpec.groovy b/cps-service/src/test/groovy/org/onap/cps/utils/JsonObjectMapperSpec.groovy
new file mode 100644
index 0000000000..f9b8febd43
--- /dev/null
+++ b/cps-service/src/test/groovy/org/onap/cps/utils/JsonObjectMapperSpec.groovy
@@ -0,0 +1,87 @@
+/*
+ *  ============LICENSE_START=======================================================
+ *  Copyright (C) 2022 Nordix Foundation
+ *  ================================================================================
+ *  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.
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *  ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.utils
+
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import groovy.json.JsonSlurper
+import org.onap.cps.TestUtils
+import org.onap.cps.spi.exceptions.DataValidationException
+import spock.lang.Specification
+
+class JsonObjectMapperSpec extends Specification {
+
+    def spiedObjectMapper = Spy(ObjectMapper)
+    def jsonObjectMapper = new JsonObjectMapper(spiedObjectMapper)
+
+    def 'Map a structured object to json String.'() {
+        given: 'an object model'
+            def object = spiedObjectMapper.readValue(TestUtils.getResourceFileContent('bookstore.json'), Object)
+        when: 'the object is mapped to string'
+            def content = jsonObjectMapper.asJsonString(object);
+        then: 'the result is a valid json string (can be parsed)'
+            def contentMap = new JsonSlurper().parseText(content)
+        and: 'the parsed content is as expected'
+            assert contentMap.'test:bookstore'.'bookstore-name' == 'Chapters'
+    }
+
+    def 'Map a structurally compatible object to class object of specific class type T.'() {
+        given: 'a map object model'
+            def contentMap = new JsonSlurper().parseText(TestUtils.getResourceFileContent('bookstore.json'))
+        when: 'converted into a Map'
+            def result = jsonObjectMapper.convertToValueType(contentMap, Map);
+        then: 'the result is a mapped into class of type Map'
+            assert result instanceof Map
+        and: 'the map contains the expected key'
+            assert result.containsKey('test:bookstore')
+            assert result.'test:bookstore'.categories[0].name == 'SciFi'
+
+    }
+
+    def 'Mapping an unstructured json string to class object of specific class type T.'() {
+        given: 'Unstructured json string'
+            def content = '{ "nest": { "birds": "bird"] } }'
+        when: 'mapping json string to given class type'
+            def contentMap = jsonObjectMapper.convertJsonString(content, Map);
+        then: 'an exception is thrown'
+            thrown(DataValidationException)
+    }
+
+    def 'Map an incompatible object to class object of specific class type T.'() {
+        given: 'a map object model'
+            def contentMap = new JsonSlurper().parseText(TestUtils.getResourceFileContent('bookstore.json'))
+        and: 'Object mapper throws an exception'
+            spiedObjectMapper.convertValue(*_) >> { throw new IllegalArgumentException() }
+        when: 'converted into specific class type'
+            jsonObjectMapper.convertToValueType(contentMap, Object);
+        then: 'an exception is thrown'
+            thrown(DataValidationException)
+    }
+
+    def 'Map a unstructured object to json String.'() {
+        given: 'Unstructured object'
+            def object = new Object()
+        when: 'the object is mapped to string'
+            jsonObjectMapper.asJsonString(object);
+        then: 'an exception is thrown'
+            thrown(DataValidationException)
+    }
+}