feat: Migrate odata v2 and odata v4 to Apache HttpClient 5

cloudplatform/connectivity-apache-httpclient5/src/main/java/com/sap/cloud/sdk/cloudplatform/connectivity/ApacheHttpClient5Accessor.java

@@ -21,6 +21,17 @@
 @NoArgsConstructor( access = AccessLevel.PRIVATE )
 public final class ApacheHttpClient5Accessor
 {
+    /**
+     * Internal request-header marker that instructs the CSRF token interceptor to skip fetching a CSRF token for the
+     * request it is attached to. The interceptor strips this header before the request is sent, so it never reaches the
+     * target system.
+     * <p>
+     * This is an implementation detail used by the OData VDM layer to preserve the legacy {@code withoutCsrfToken()}
+     * opt-out behavior and is not intended for direct use by applications.
+     */
+    @Nonnull
+    public static final String SKIP_CSRF_TOKEN_HEADER = "x-sap-sdk-skip-csrf-token";
+
     /**
      * Configures the {@code HttpClient5Cache} that is used by the {@code #getHttpClient(String)} and
      * {@code #getHttpClient(Destination)} methods.

cloudplatform/connectivity-apache-httpclient5/src/main/java/com/sap/cloud/sdk/cloudplatform/connectivity/CsrfTokenInterceptor.java

@@ -39,6 +39,12 @@ class CsrfTokenInterceptor implements HttpRequestInterceptor
             throws HttpException,
                 IOException
     {
+        if( request.containsHeader(ApacheHttpClient5Accessor.SKIP_CSRF_TOKEN_HEADER) ) {
+            request.removeHeaders(ApacheHttpClient5Accessor.SKIP_CSRF_TOKEN_HEADER);
+            log.debug("CSRF token retrieval explicitly disabled for this request, skipping.");
+            return;
+        }
+
         if( !MUTATING_METHODS.contains(request.getMethod().toUpperCase()) ) {
             return;
         }

cloudplatform/connectivity-apache-httpclient5/src/test/java/com/sap/cloud/sdk/cloudplatform/connectivity/CsrfTokenInterceptorTest.java

@@ -119,6 +119,33 @@ void tokenIsNotFetchedWhenAlreadyPresent()
             .isEqualTo("existing-token");
     }
 
+    @Test
+    @SneakyThrows
+    void tokenIsNotFetchedAndMarkerIsStrippedWhenSkipHeaderPresent()
+    {
+        final HttpPost request = new HttpPost(REQUEST_PATH);
+        request.addHeader(ApacheHttpClient5Accessor.SKIP_CSRF_TOKEN_HEADER, "true");
+
+        sut.process(request, null, null);
+
+        verify(mockHttpClient, never()).execute(any(), ArgumentMatchers.<HttpClientResponseHandler<String>> any());
+        assertThat(request.getFirstHeader(CsrfTokenInterceptor.X_CSRF_TOKEN_HEADER_KEY)).isNull();
+        assertThat(request.containsHeader(ApacheHttpClient5Accessor.SKIP_CSRF_TOKEN_HEADER)).isFalse();
+    }
+
+    @Test
+    @SneakyThrows
+    void skipMarkerIsStrippedEvenOnGetRequest()
+    {
+        final HttpGet request = new HttpGet(REQUEST_PATH);
+        request.addHeader(ApacheHttpClient5Accessor.SKIP_CSRF_TOKEN_HEADER, "true");
+
+        sut.process(request, null, null);
+
+        verify(mockHttpClient, never()).execute(any(), ArgumentMatchers.<HttpClientResponseHandler<String>> any());
+        assertThat(request.containsHeader(ApacheHttpClient5Accessor.SKIP_CSRF_TOKEN_HEADER)).isFalse();
+    }
+
     @Test
     @SneakyThrows
     void requestProceedsWithoutTokenWhenServerReturnsNoHeader( final WireMockRuntimeInfo wm )

datamodel/odata-core-apache-httpclient5/pom.xml

@@ -0,0 +1,126 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>com.sap.cloud.sdk.datamodel</groupId>
+		<artifactId>datamodel-parent</artifactId>
+		<version>5.35.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>odata-core-apache-httpclient5</artifactId>
+	<packaging>jar</packaging>
+	<name>Data Model - OData Services - Core (HttpClient 5)</name>
+	<description>OData Services data model (VDM) - core classes using Apache HttpClient 5.</description>
+	<url>https://sap.github.io/cloud-sdk/docs/java/getting-started</url>
+	<organization>
+		<name>SAP SE</name>
+		<url>https://www.sap.com</url>
+	</organization>
+	<licenses>
+		<license>
+			<name>The Apache Software License, Version 2.0</name>
+			<url>https://www.apache.org/licenses/LICENSE-2.0.txt</url>
+		</license>
+	</licenses>
+	<developers>
+		<developer>
+			<name>SAP</name>
+			<email>cloudsdk@sap.com</email>
+			<organization>SAP SE</organization>
+			<organizationUrl>https://www.sap.com</organizationUrl>
+		</developer>
+	</developers>
+	<properties>
+		<jsr305.optional>false</jsr305.optional>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>com.sap.cloud.sdk.datamodel</groupId>
+			<artifactId>odata-client-apache-httpclient5</artifactId>
+			<version>${project.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>com.sap.cloud.sdk.cloudplatform</groupId>
+			<artifactId>cloudplatform-core</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.sap.cloud.sdk.cloudplatform</groupId>
+			<artifactId>cloudplatform-connectivity</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.sap.cloud.sdk.cloudplatform</groupId>
+			<artifactId>connectivity-apache-httpclient5</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.sap.cloud.sdk.datamodel</groupId>
+			<artifactId>fluent-result</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.slf4j</groupId>
+			<artifactId>slf4j-api</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.google.guava</groupId>
+			<artifactId>guava</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.google.code.gson</groupId>
+			<artifactId>gson</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-annotations</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-core</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-databind</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.httpcomponents.core5</groupId>
+			<artifactId>httpcore5</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.httpcomponents.client5</groupId>
+			<artifactId>httpclient5</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>io.vavr</groupId>
+			<artifactId>vavr</artifactId>
+		</dependency>
+		<!-- scope "provided" -->
+		<dependency>
+			<groupId>org.projectlombok</groupId>
+			<artifactId>lombok</artifactId>
+			<scope>provided</scope>
+		</dependency>
+		<!-- scope "test" -->
+		<dependency>
+			<groupId>org.assertj</groupId>
+			<artifactId>assertj-core</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-core</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.wiremock</groupId>
+			<artifactId>wiremock</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-api</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-params</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+</project>

datamodel/odata-core-apache-httpclient5/src/main/java/com/sap/cloud/sdk/datamodel/odata/adapter/ODataNumberSerializer.java

@@ -0,0 +1,40 @@
+package com.sap.cloud.sdk.datamodel.odata.adapter;
+
+import java.lang.reflect.Type;
+import java.math.BigDecimal;
+
+import javax.annotation.Nonnull;
+
+import com.google.gson.JsonElement;
+import com.google.gson.JsonPrimitive;
+import com.google.gson.JsonSerializationContext;
+import com.google.gson.JsonSerializer;
+
+/**
+ * GSON serializer that transforms numbers to their JSON representation according to the OData V2 standard. Meant for
+ * internal use only.
+ */
+public class ODataNumberSerializer implements JsonSerializer<Number>
+{
+    @Override
+    @Nonnull
+    public JsonElement serialize(
+        @Nonnull final Number src,
+        @Nonnull final Type typeOfSrc,
+        @Nonnull final JsonSerializationContext context )
+    {
+        /*
+        Short is used both for Edm.Byte and Edm.Int16.
+        Edm.Byte should be a string but Edm.Int16 should be a number.
+        But we can't differentiate between that here because we only know it's a Short.
+        So we serialize to the plain number because this worked in the past.
+         */
+        if( typeOfSrc == Integer.class || typeOfSrc == Short.class ) {
+            return new JsonPrimitive(src);
+        } else if( typeOfSrc == BigDecimal.class ) {
+            return new JsonPrimitive(((BigDecimal) src).toPlainString());
+        } else {
+            return new JsonPrimitive(src.toString());
+        }
+    }
+}

datamodel/odata-core-apache-httpclient5/src/main/java/com/sap/cloud/sdk/datamodel/odata/helper/CollectionValuedFluentHelperFunction.java

@@ -0,0 +1,32 @@
+package com.sap.cloud.sdk.datamodel.odata.helper;
+
+import javax.annotation.Nonnull;
+
+/**
+ * Representation of any OData function import as a fluent class for further configuring the request and
+ * {@link #executeRequest(Destination) executing} it.This is specifically for functions that return either a collection
+ * of primitive values or entities
+ *
+ * @param <FluentHelperT>
+ *            The fluent helper type.
+ * @param <ObjectT>
+ *            The type of the object this OData request operates on, if any.
+ * @param <ResultT>
+ *            The type of the result entity, if any.
+ */
+public abstract class CollectionValuedFluentHelperFunction<FluentHelperT, ObjectT, ResultT>
+    extends
+    FluentHelperFunction<FluentHelperT, ObjectT, ResultT>
+{
+
+    /**
+     * Instantiates this fluent helper using the given service path to send the requests.
+     *
+     * @param servicePath
+     *            The service path to direct the requests to.
+     */
+    public CollectionValuedFluentHelperFunction( @Nonnull final String servicePath )
+    {
+        super(servicePath);
+    }
+}