Gsonを使用してInputStreamから来るJSONオブジェクトの配列を解析する方法

Question

ClientResponseFilterを使用してRESTサーバーの応答を傍受する必要があるという要件があります。サーバーは、以下の例に示すようにJSONオブジェクトの配列を送信しています。

[ 
    { 
     "id":101, 
     "fname":"Mike", 
     "lname":"Smith", 
     "age":25, 
     "country":"France" 
    }, 
    { 
     "id":102, 
     "fname":"Emily", 
     "lname":"Clarke", 
     "age":26, 
     "country":"Canada" 
    }, 
    { 
     "id":103, 
     "fname":"Jennifer", 
     "lname":"Carsova", 
     "age":27, 
     "country":"Germany" 
    } 
] 

私は、これらの各オブジェクトにURLと呼ばれる新しいプロパティを追加する必要がある要件を持っています。 URLフィールドの値は、www.abc.comのような値になります。

は、私は私のフィルタでこのメソッドをオーバーライドする必要が
public void filter(ClientRequestContext requestContext, ClientResponseContext responseContext)
ClientResponseContextは応答のコンテンツへの入力ストリームを提供getEntityStream()と呼ばれる方法があります。 JSONオブジェクトのそれぞれに新しいプロパティを追加できたら、setEntityStream()メソッドを使用して、新しいストリーム（追加されたプロパティ付き）を渡します。
私はこれを達成するためにGsonを使用しています。下は試したコードですが、動作しません。

public class SomeFilter implements ClientResponseFilter { 

    @Override 
    public void filter(ClientRequestContext requestContext, ClientResponseContext responseContext) throws IOException { 

     JsonReader jsonReader = new JsonReader(new InputStreamReader(responseContext.getEntityStream(), "UTF-8")); 
     JsonArray jsonArray = new JsonArray(); 
     JsonParser jsonParser = new JsonParser(); 
     JsonElement jsonElement; 
     JsonObject jsonObject; 

     while(jsonReader.hasNext()) { 

      jsonReader.beginObject();  // I tried using jsonReader.beginArray() as well but this also does not work 

      while(jsonReader.hasNext()) { 
       jsonElement = jsonParser.parse(jsonReader);  // Throws an IllegalArgumentException here 
       jsonObject = jsonElement.getAsJsonObject(); 
       jsonObject.addProperty("URL", "www.abc.com"); 
       jsonArray.add(jsonObject); 
      } 
     } 

     InputStream inputStream = new ByteArrayInputStream(jsonArray.toString().getBytes()); 
     responseContext.setEntityStream(inputStream); 

    } 
} 

以下は、私が得ているエラーです。

15:04:38,070 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[default-host].[/cq/release-management].[com.jackson.release.management.rest.application.ReleaseManagementApplication]](http-localhost/127.0.0.1:8080-1) JBWEB000236: Servlet.service() for servlet com.jackson.release.management.rest.application.ReleaseManagementApplication threw exception: org.jboss.resteasy.spi.UnhandledException: javax.ws.rs.ProcessingException 
    at org.jboss.resteasy.core.ExceptionHandler.handleApplicationException(ExceptionHandler.java:76) [resteasy-jaxrs-3.0.8.Final.jar:] 
    at org.jboss.resteasy.core.ExceptionHandler.handleException(ExceptionHandler.java:212) [resteasy-jaxrs-3.0.8.Final.jar:] 
    at org.jboss.resteasy.core.SynchronousDispatcher.writeException(SynchronousDispatcher.java:149) [resteasy-jaxrs-3.0.8.Final.jar:] 
    at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:372) [resteasy-jaxrs-3.0.8.Final.jar:] 
    at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:179) [resteasy-jaxrs-3.0.8.Final.jar:] 
    at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:220) [resteasy-jaxrs-3.0.8.Final.jar:] 
    at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56) [resteasy-jaxrs-3.0.8.Final.jar:] 
    at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:51) [resteasy-jaxrs-3.0.8.Final.jar:] 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:847) [jboss-servlet-api_3.0_spec-1.0.2.Final-redhat-1.jar:1.0.2.Final-redhat-1] 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:295) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at com.jackson.sdlc.service.security.PrismSecurityContextFilter.doFilter(PrismSecurityContextFilter.java:57) [prism-util-1.1.0.jar:] 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:231) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:149) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:512) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at org.jboss.as.web.security.SecurityContextAssociationValve.invoke(SecurityContextAssociationValve.java:169) [jboss-as-web-7.4.0.Final-redhat-19.jar:7.4.0.Final-redhat-19] 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:145) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:97) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:102) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:344) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:653) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:926) [jbossweb-7.4.8.Final-redhat-4.jar:7.4.8.Final-redhat-4] 
    at java.lang.Thread.run(Thread.java:745) [rt.jar:1.8.0_77] 
Caused by: javax.ws.rs.ProcessingException 
    at org.glassfish.jersey.client.ClientRuntime.invoke(ClientRuntime.java:264) [jersey-client-2.22.1.jar:] 
    at org.glassfish.jersey.client.JerseyInvocation$3.call(JerseyInvocation.java:722) [jersey-client-2.22.1.jar:] 
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315) [jersey-common-2.22.1.jar:] 
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297) [jersey-common-2.22.1.jar:] 
    at org.glassfish.jersey.internal.Errors.process(Errors.java:228) [jersey-common-2.22.1.jar:] 
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:444) [jersey-common-2.22.1.jar:] 
    at org.glassfish.jersey.client.JerseyInvocation.invoke(JerseyInvocation.java:718) [jersey-client-2.22.1.jar:] 
    at org.glassfish.jersey.client.JerseyInvocation$Builder.method(JerseyInvocation.java:430) [jersey-client-2.22.1.jar:] 
    at org.glassfish.jersey.client.proxy.WebResourceFactory.invoke(WebResourceFactory.java:345) [jersey-proxy-client-2.22.1.jar:] 
    at com.sun.proxy.$Proxy223.getProjectsByReleaseDate(Unknown Source) 
    at com.jackson.workfront.service.WorkfrontProjectServiceImpl.getProjectsByReleaseDate(WorkfrontProjectServiceImpl.java:69) [workfront-rest-client-impl-1.1.1-SNAPSHOT.jar:] 
    at com.jackson.release.management.impl.ProjectServiceRestImpl.getProjectsRelatedToRelease(ProjectServiceRestImpl.java:30) [classes:] 
    at com.jackson.release.management.impl.ProjectServiceRestImpl$Proxy$_$$_WeldClientProxy.getProjectsRelatedToRelease(ProjectServiceRestImpl$Proxy$_$$_WeldClientProxy.java) [classes:] 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.8.0_77] 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) [rt.jar:1.8.0_77] 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.8.0_77] 
    at java.lang.reflect.Method.invoke(Method.java:498) [rt.jar:1.8.0_77] 
    at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:137) [resteasy-jaxrs-3.0.8.Final.jar:] 
    at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:296) [resteasy-jaxrs-3.0.8.Final.jar:] 
    at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:250) [resteasy-jaxrs-3.0.8.Final.jar:] 
    at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:237) [resteasy-jaxrs-3.0.8.Final.jar:] 
    at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:356) [resteasy-jaxrs-3.0.8.Final.jar:] 
    ... 22 more 
Caused by: java.lang.IllegalArgumentException 
    at com.google.gson.internal.bind.TypeAdapters$25.read(TypeAdapters.java:676) [gson-2.2.4.jar:] 
    at com.google.gson.internal.bind.TypeAdapters$25.read(TypeAdapters.java:642) [gson-2.2.4.jar:] 
    at com.google.gson.internal.Streams.parse(Streams.java:44) [gson-2.2.4.jar:] 
    at com.google.gson.JsonParser.parse(JsonParser.java:84) [gson-2.2.4.jar:] 
    at com.jackson.workfront.client.filter.SomeFilter.filter(SomeFilter.java:58) [workfront-rest-client-impl-1.1.1-SNAPSHOT.jar:] 
    at org.glassfish.jersey.client.ClientFilteringStages$ResponseFilterStage.apply(ClientFilteringStages.java:140) [jersey-client-2.22.1.jar:] 
    at org.glassfish.jersey.client.ClientFilteringStages$ResponseFilterStage.apply(ClientFilteringStages.java:128) [jersey-client-2.22.1.jar:] 
    at org.glassfish.jersey.process.internal.Stages.process(Stages.java:171) [jersey-common-2.22.1.jar:] 
    at org.glassfish.jersey.client.ClientRuntime.invoke(ClientRuntime.java:260) [jersey-client-2.22.1.jar:] 
    ... 43 more 

私はstackoverflowで見つかったすべての他の回答を試みましたが、どれも動作しません。

私のコードの問題と解決方法を教えてもらえますか？

Answer 1

ストリームをパーザに直接渡すのではなく、パーサーのみで作業するのはなぜですか？

Answer 2

Gsonを効率的に使用しているとは思わない。使用できる機能の1つは、JSONをJavaオブジェクトにマーシャリングする方法です。あなたはInputStreamからそれらのオブジェクトのリストをデシリアライズするGsonを伝えることができ、ここから

public class Person { 
    int id; 
    String fname; 
    String lname; 
    int age; 
    String country; 

    @SerializedName("URL") 
    String url; 
} 

：：だから、あなたの例JSONのために、私は次のようなクラスが一人となるであろうと想像

InputStream stream = responseContext.getEntityStream(); 
Gson gson = new GsonBuilder().create(); 

Type type = new TypeToken<List<Person>>(){}.getType(); 
List<Person> people = gson.fromJson(new InputStreamReader(stream, StandardCharsets.UTF_8), type); 

for(Person person : people) { 
    person.url = "www.abc.com"; 
} 

String json = gson.toJson(people); 
InputStream inputStream = new ByteArrayInputStream(json.getBytes(StandardCharsets.UTF_8)); 
responseContext.setEntityStream(inputStream);