Extracted http request handler

Author: oliemansm

build.gradle

@@ -11,6 +11,7 @@ plugins {
     id "com.jfrog.bintray" version "1.8.4"
     id "com.jfrog.artifactory" version "4.8.1"
     id 'net.researchgate.release' version '2.7.0'
+    id 'io.franzbecker.gradle-lombok' version '3.1.0'
 }
 
 apply plugin: 'java'
@@ -25,10 +26,6 @@ repositories {
     mavenCentral()
 }
 
-configurations.all {
-    exclude group:"org.projectlombok", module: "lombok"
-}
-
 dependencies {
     compile 'org.slf4j:slf4j-api:1.7.21'
 
@@ -210,3 +207,7 @@ idea {
 wrapper {
     gradleVersion = '4.10.3'
 }
+
+lombok {
+    version = '1.18.10'
+}

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Thu Jun 20 12:32:36 CEST 2019
+#Thu Nov 14 18:53:34 CET 2019
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.3-all.zip
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.3-all.zip
+zipStoreBase=GRADLE_USER_HOME

src/main/java/graphql/servlet/AbstractGraphQLHttpServlet.java

@@ -0,0 +1,40 @@
+package graphql.servlet;
+
+import static graphql.servlet.HttpRequestHandler.APPLICATION_JSON_UTF8;
+import static graphql.servlet.HttpRequestHandler.STATUS_OK;
+
+import graphql.ExecutionResult;
+import graphql.servlet.core.GraphQLObjectMapper;
+import java.io.IOException;
+import java.io.Writer;
+import java.util.Iterator;
+import java.util.List;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+class BatchedQueryResponseWriter implements QueryResponseWriter {
+
+  private final List<ExecutionResult> results;
+  private final GraphQLObjectMapper graphQLObjectMapper;
+
+  @Override
+  public void write(HttpServletRequest request, HttpServletResponse response) throws IOException {
+    response.setContentType(APPLICATION_JSON_UTF8);
+    response.setStatus(STATUS_OK);
+
+    Writer writer = response.getWriter();
+    Iterator<ExecutionResult> executionInputIterator = results.iterator();
+    writer.write("[");
+    while (executionInputIterator.hasNext()) {
+      String result = graphQLObjectMapper.serializeResultAsJson(executionInputIterator.next());
+      writer.write(result);
+      if (executionInputIterator.hasNext()) {
+        writer.write(",");
+      }
+    }
+    writer.write("]");
+  }
+
+}

src/main/java/graphql/servlet/BatchedQueryResponseWriter.java

@@ -0,0 +1,53 @@
+package graphql.servlet;
+
+import graphql.ExecutionResult;
+import graphql.GraphQL;
+import graphql.GraphQLError;
+import java.util.List;
+import java.util.Map;
+import lombok.RequiredArgsConstructor;
+import org.reactivestreams.Publisher;
+
+@RequiredArgsConstructor
+class DecoratedExecutionResult implements ExecutionResult {
+
+  private final ExecutionResult result;
+
+  static DecoratedExecutionResult decorate(ExecutionResult result) {
+    return new DecoratedExecutionResult(result);
+  }
+
+  boolean isAsynchronous() {
+    return result.getData() instanceof Publisher || isDeferred();
+  }
+
+  boolean isDeferred() {
+    return result.getExtensions() != null && result.getExtensions().containsKey(GraphQL.DEFERRED_RESULTS);
+  }
+
+  @Override
+  public List<GraphQLError> getErrors() {
+    return result.getErrors();
+  }
+
+  @Override
+  public <T> T getData() {
+    return result.getData();
+  }
+
+  @Override
+  public boolean isDataPresent() {
+    return result.isDataPresent();
+  }
+
+  @Override
+  public Map<Object, Object> getExtensions() {
+    return result.getExtensions();
+  }
+
+  @Override
+  public Map<String, Object> toSpecification() {
+    return result.toSpecification();
+  }
+
+}

src/main/java/graphql/servlet/DecoratedExecutionResult.java

@@ -0,0 +1,19 @@
+package graphql.servlet;
+
+import java.io.IOException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+class ErrorQueryResponseWriter implements QueryResponseWriter {
+
+  private final int statusCode;
+  private final String message;
+
+  @Override
+  public void write(HttpServletRequest request, HttpServletResponse response) throws IOException {
+    response.sendError(statusCode, message);
+  }
+
+}

src/main/java/graphql/servlet/ErrorQueryResponseWriter.java

@@ -0,0 +1,62 @@
+package graphql.servlet;
+
+import graphql.ExecutionResult;
+import graphql.servlet.core.GraphQLObjectMapper;
+import java.io.IOException;
+import java.io.Writer;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicReference;
+import javax.servlet.AsyncContext;
+import org.reactivestreams.Subscriber;
+import org.reactivestreams.Subscription;
+
+class ExecutionResultSubscriber implements Subscriber<ExecutionResult> {
+
+  private final AtomicReference<Subscription> subscriptionRef;
+  private final AsyncContext asyncContext;
+  private final GraphQLObjectMapper graphQLObjectMapper;
+  private final CountDownLatch completedLatch = new CountDownLatch(1);
+
+  public ExecutionResultSubscriber(AtomicReference<Subscription> subscriptionRef, AsyncContext asyncContext,
+      GraphQLObjectMapper graphQLObjectMapper) {
+    this.subscriptionRef = subscriptionRef;
+    this.asyncContext = asyncContext;
+    this.graphQLObjectMapper = graphQLObjectMapper;
+  }
+
+  @Override
+  public void onSubscribe(Subscription subscription) {
+    subscriptionRef.set(subscription);
+    subscriptionRef.get().request(1);
+  }
+
+  @Override
+  public void onNext(ExecutionResult executionResult) {
+    try {
+      Writer writer = asyncContext.getResponse().getWriter();
+      writer.write("data: ");
+      graphQLObjectMapper.serializeResultAsJson(writer, executionResult);
+      writer.write("\n\n");
+      writer.flush();
+      subscriptionRef.get().request(1);
+    } catch (IOException ignored) {
+    }
+  }
+
+  @Override
+  public void onError(Throwable t) {
+    asyncContext.complete();
+    completedLatch.countDown();
+  }
+
+  @Override
+  public void onComplete() {
+    asyncContext.complete();
+    completedLatch.countDown();
+  }
+
+  public void await() throws InterruptedException {
+    completedLatch.await();
+  }
+
+}

src/main/java/graphql/servlet/ExecutionResultSubscriber.java

@@ -0,0 +1,24 @@
+package graphql.servlet;
+
+import graphql.ExecutionResult;
+import java.util.List;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+class GraphQLBatchedQueryResult implements GraphQLQueryResult {
+
+  @Getter
+  private final List<ExecutionResult> results;
+
+  @Override
+  public boolean isBatched() {
+    return true;
+  }
+
+  @Override
+  public boolean isAsynchronous() {
+    return false;
+  }
+
+}

src/main/java/graphql/servlet/GraphQLBatchedQueryResult.java

@@ -0,0 +1,29 @@
+package graphql.servlet;
+
+import graphql.ExecutionResult;
+import java.util.List;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@Getter
+@RequiredArgsConstructor
+class GraphQLErrorQueryResult implements GraphQLQueryResult {
+
+  private final int statusCode;
+  private final String message;
+
+  @Override
+  public boolean isBatched() {
+    return true;
+  }
+
+  @Override
+  public boolean isAsynchronous() {
+    return false;
+  }
+
+  @Override
+  public boolean isError() {
+    return true;
+  }
+}

src/main/java/graphql/servlet/GraphQLErrorQueryResult.java

@@ -0,0 +1,63 @@
+package graphql.servlet;
+
+import graphql.servlet.context.ContextSetting;
+import graphql.servlet.core.GraphQLObjectMapper;
+import graphql.servlet.core.internal.GraphQLRequest;
+import graphql.servlet.input.GraphQLInvocationInput;
+import graphql.servlet.input.GraphQLInvocationInputFactory;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor
+class GraphQLInvocationInputParser {
+
+  private final GraphQLInvocationInputFactory invocationInputFactory;
+  private final GraphQLObjectMapper graphQLObjectMapper;
+  private final ContextSetting contextSetting;
+
+  GraphQLInvocationInput getGraphQLInvocationInput(HttpServletRequest request, HttpServletResponse response)
+      throws IOException {
+    if (isIntrospectionQuery(request)) {
+      GraphQLRequest graphqlRequest = GraphQLRequest.createIntrospectionRequest();
+      return invocationInputFactory.create(graphqlRequest, request, response);
+    }
+
+    String query = request.getParameter("query");
+    if (!isBatchedQuery(query)) {
+      Map<String, Object> variables = getVariables(request);
+      String operationName = request.getParameter("operationName");
+      GraphQLRequest graphqlRequest = new GraphQLRequest(query, variables, operationName);
+      return invocationInputFactory.create(graphqlRequest, request, response);
+    }
+
+    List<GraphQLRequest> requests = graphQLObjectMapper.readBatchedGraphQLRequest(query);
+    return invocationInputFactory.createReadOnly(contextSetting, requests, request, response);
+  }
+
+  private boolean isIntrospectionQuery(HttpServletRequest request) {
+    String path = Optional.ofNullable(request.getPathInfo()).orElseGet(request::getServletPath).toLowerCase();
+    return path.contentEquals("/schema.json");
+  }
+
+  private Map<String, Object> getVariables(HttpServletRequest request) {
+    return Optional.ofNullable(request.getParameter("variables"))
+        .map(graphQLObjectMapper::deserializeVariables)
+        .map(HashMap::new)
+        .orElseGet(HashMap::new);
+  }
+
+  private boolean isBatchedQuery(String query) {
+    return isArrayStart(query);
+  }
+
+  private boolean isArrayStart(String s) {
+    return s != null && s.trim().startsWith("[");
+  }
+
+}