diff options
Diffstat (limited to 'policy-endpoints/src/main/java/org/onap/policy/common/endpoints/http/server/internal/GsonMessageBodyHandler.java')
-rw-r--r-- | policy-endpoints/src/main/java/org/onap/policy/common/endpoints/http/server/internal/GsonMessageBodyHandler.java | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/http/server/internal/GsonMessageBodyHandler.java b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/http/server/internal/GsonMessageBodyHandler.java new file mode 100644 index 00000000..a29afef4 --- /dev/null +++ b/policy-endpoints/src/main/java/org/onap/policy/common/endpoints/http/server/internal/GsonMessageBodyHandler.java @@ -0,0 +1,128 @@ +/* + * ============LICENSE_START======================================================= + * ONAP + * ================================================================================ + * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved. + * ================================================================================ + * 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. + * ============LICENSE_END========================================================= + */ + +package org.onap.policy.common.endpoints.http.server.internal; + +import com.google.gson.Gson; +import java.io.IOException; +import java.io.InputStream; +import java.io.InputStreamReader; +import java.io.OutputStream; +import java.io.OutputStreamWriter; +import java.lang.annotation.Annotation; +import java.lang.reflect.Type; +import java.nio.charset.StandardCharsets; +import javax.ws.rs.Consumes; +import javax.ws.rs.Produces; +import javax.ws.rs.WebApplicationException; +import javax.ws.rs.core.MediaType; +import javax.ws.rs.core.MultivaluedMap; +import javax.ws.rs.ext.MessageBodyReader; +import javax.ws.rs.ext.MessageBodyWriter; +import javax.ws.rs.ext.Provider; + +/** + * Provider that serializes and de-serializes JSON via gson. + * + * <p>Note: <i>jersey</i> will ignore this class if the maven artifact, + * <i>jersey-media-json-jackson</i>, is included, regardless of whether it's included + * directly or indirectly. + */ +@Provider +@Consumes(MediaType.WILDCARD) +@Produces(MediaType.WILDCARD) +public class GsonMessageBodyHandler implements MessageBodyReader<Object>, MessageBodyWriter<Object> { + + /** + * Object to be used to serialize and de-serialize. + */ + private Gson gson; + + /** + * Constructs the object, using a plain Gson object. + */ + public GsonMessageBodyHandler() { + this(new Gson()); + } + + /** + * Constructs the object. + * + * @param gson the Gson object to be used to serialize and de-serialize + */ + public GsonMessageBodyHandler(Gson gson) { + this.gson = gson; + } + + @Override + public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) { + return canHandle(mediaType); + } + + @Override + public long getSize(Object object, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) { + return -1; + } + + @Override + public void writeTo(Object object, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType, + MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream) + throws IOException, WebApplicationException { + + try (OutputStreamWriter writer = new OutputStreamWriter(entityStream, StandardCharsets.UTF_8)) { + Type jsonType = (type.equals(genericType) ? type : genericType); + gson.toJson(object, jsonType, writer); + } + } + + @Override + public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) { + return canHandle(mediaType); + } + + /** + * Determines if this provider can handle the given media type. + * + * @param mediaType the media type of interest + * @return {@code true} if this provider handles the given media type, {@code false} + * otherwise + */ + private boolean canHandle(MediaType mediaType) { + if (mediaType == null) { + return true; + } + + String subtype = mediaType.getSubtype(); + + return "json".equalsIgnoreCase(subtype) || subtype.endsWith("+json") || "javascript".equals(subtype) + || "x-javascript".equals(subtype) || "x-json".equals(subtype); + } + + @Override + public Object readFrom(Class<Object> type, Type genericType, Annotation[] annotations, MediaType mediaType, + MultivaluedMap<String, String> httpHeaders, InputStream entityStream) + throws IOException, WebApplicationException { + + try (InputStreamReader streamReader = new InputStreamReader(entityStream, StandardCharsets.UTF_8)) { + Type jsonType = (type.equals(genericType) ? type : genericType); + return gson.fromJson(streamReader, jsonType); + } + } +} |