Add an integration test that runs on JDK-8

.github/workflows/test-jdk8-compat-unit.yml

@@ -0,0 +1,30 @@
+name: Compatibility Unit Tests (JDK-8)
+
+on: [push, pull_request]
+
+jobs:
+  test:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macOS-latest]
+    steps:
+      - name: Checkout Java Client
+        uses: actions/checkout@v3
+
+      - name: Set up JDK 8
+        uses: actions/setup-java@v3
+        with:
+          java-version: 8
+          distribution: 'temurin'
+          cache: 'gradle'
+
+      - name: Set up JDK 11
+        uses: actions/setup-java@v3
+        with:
+          java-version: 11
+          distribution: 'temurin'
+          cache: 'gradle'
+
+      - name: Run Unit Test
+        run: ./gradlew clean unitTest -Pcheck-jdk8-compatibility=true

CHANGELOG.md

@@ -49,6 +49,7 @@ This section is for maintaining a changelog for all breaking changes for the cli
 
 ### Changed
 - Restore support for Java 8 ([#767](https://github.com/opensearch-project/opensearch-java/pull/767))
+- Add an integration test that runs on JDK-8 ([#795](https://github.com/opensearch-project/opensearch-java/pull/795))
 
 ### Deprecated
 - Deprecated "_toQuery()" in Query and QueryVariant ([#760](https://github.com/opensearch-project/opensearch-java/pull/760)

java-client/build.gradle.kts

@@ -32,6 +32,7 @@
 
 import com.github.jk1.license.ProjectData
 import com.github.jk1.license.render.ReportRenderer
+import org.gradle.api.tasks.testing.Test
 import java.io.FileWriter
 
 buildscript {
@@ -337,7 +338,9 @@ publishing {
     }
 }
 
-if (JavaVersion.current() >= JavaVersion.VERSION_11) {
+// Use `-Pcheck-jdk8-compatibility=true` to
+val jdk8compatibility = (project.findProperty("check-jdk8-compatibility") as String?).toBoolean()
+if (JavaVersion.current() >= JavaVersion.VERSION_11 && jdk8compatibility == false) {
   val java11: SourceSet = sourceSets.create("java11") {
     java {
       compileClasspath += sourceSets.main.get().output + sourceSets.test.get().output
@@ -369,5 +372,17 @@ if (JavaVersion.current() >= JavaVersion.VERSION_11) {
     testClassesDirs += java11.output.classesDirs
     classpath = sourceSets["java11"].runtimeClasspath
   }
-
+} else if (jdk8compatibility == true) {
+    java {
+        toolchain {
+          languageVersion = JavaLanguageVersion.of(8)
+          vendor = JvmVendorSpec.ADOPTIUM
+        }
+    }
+
+    tasks.register<Test>("tests-jdk8") {
+      javaLauncher = javaToolchains.launcherFor {
+        languageVersion = JavaLanguageVersion.of(8)
+      }
+    }
 }

java-client/src/test/java/org/opensearch/client/opensearch/_types/query_dsl/GeoDistanceQueryTest.java

@@ -1,6 +1,6 @@
 package org.opensearch.client.opensearch._types.query_dsl;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Test;
 import org.opensearch.client.opensearch._types.GeoLocation;
 import org.opensearch.client.opensearch.model.ModelTestCase;
@@ -9,7 +9,7 @@ public class GeoDistanceQueryTest extends ModelTestCase {
     @Test
     public void toBuilder() {
         GeoDistanceQuery origin = new GeoDistanceQuery.Builder().field("field")
-            .location(new GeoLocation.Builder().coords(List.of(1.0)).build())
+            .location(new GeoLocation.Builder().coords(Collections.singletonList(1.0)).build())
             .build();
         GeoDistanceQuery copied = origin.toBuilder().build();
 

java-client/src/test/java/org/opensearch/client/opensearch/_types/query_dsl/PinnedQueryTest.java

@@ -1,14 +1,14 @@
 package org.opensearch.client.opensearch._types.query_dsl;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Test;
 import org.opensearch.client.opensearch._types.FieldValue;
 import org.opensearch.client.opensearch.model.ModelTestCase;
 
 public class PinnedQueryTest extends ModelTestCase {
     @Test
     public void toBuilder() {
-        PinnedQuery origin = new PinnedQuery.Builder().organic(buildDummyQuery()).ids(List.of("1")).build();
+        PinnedQuery origin = new PinnedQuery.Builder().organic(buildDummyQuery()).ids(Collections.singletonList("1")).build();
         PinnedQuery copied = origin.toBuilder().build();
 
         assertEquals(toJson(copied), toJson(origin));

java-client/src/test/java/org/opensearch/client/opensearch/_types/query_dsl/SpanContainingQueryTest.java

@@ -1,15 +1,15 @@
 package org.opensearch.client.opensearch._types.query_dsl;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Test;
 import org.opensearch.client.opensearch.model.ModelTestCase;
 
 public class SpanContainingQueryTest extends ModelTestCase {
     @Test
     public void toBuilder() {
         SpanContainingQuery origin = new SpanContainingQuery.Builder().big(
-            new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(List.of()).build()).build()
-        ).little(new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(List.of()).build()).build()).build();
+            new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(Collections.emptyList()).build()).build()
+        ).little(new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(Collections.emptyList()).build()).build()).build();
         SpanContainingQuery copied = origin.toBuilder().build();
 
         assertEquals(toJson(copied), toJson(origin));

java-client/src/test/java/org/opensearch/client/opensearch/_types/query_dsl/SpanFieldMaskingQueryTest.java

@@ -1,14 +1,14 @@
 package org.opensearch.client.opensearch._types.query_dsl;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Test;
 import org.opensearch.client.opensearch.model.ModelTestCase;
 
 public class SpanFieldMaskingQueryTest extends ModelTestCase {
     @Test
     public void toBuilder() {
         SpanFieldMaskingQuery origin = new SpanFieldMaskingQuery.Builder().field("field")
-            .query(new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(List.of()).build()).build())
+            .query(new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(Collections.emptyList()).build()).build())
             .build();
         SpanFieldMaskingQuery copied = origin.toBuilder().build();
 

java-client/src/test/java/org/opensearch/client/opensearch/_types/query_dsl/SpanFirstQueryTest.java

@@ -1,14 +1,14 @@
 package org.opensearch.client.opensearch._types.query_dsl;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Test;
 import org.opensearch.client.opensearch.model.ModelTestCase;
 
 public class SpanFirstQueryTest extends ModelTestCase {
     @Test
     public void toBuilder() {
         SpanFirstQuery origin = new SpanFirstQuery.Builder().end(1)
-            .match(new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(List.of()).build()).build())
+            .match(new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(Collections.emptyList()).build()).build())
             .build();
         SpanFirstQuery copied = origin.toBuilder().build();
 

java-client/src/test/java/org/opensearch/client/opensearch/_types/query_dsl/SpanNearQueryTest.java

@@ -1,14 +1,16 @@
 package org.opensearch.client.opensearch._types.query_dsl;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Test;
 import org.opensearch.client.opensearch.model.ModelTestCase;
 
 public class SpanNearQueryTest extends ModelTestCase {
     @Test
     public void toBuilder() {
         SpanNearQuery origin = new SpanNearQuery.Builder().clauses(
-            List.of(new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(List.of()).build()).build())
+            Collections.singletonList(
+                new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(Collections.emptyList()).build()).build()
+            )
         ).build();
         SpanNearQuery copied = origin.toBuilder().build();
 

java-client/src/test/java/org/opensearch/client/opensearch/_types/query_dsl/SpanNotQueryTest.java

@@ -1,15 +1,15 @@
 package org.opensearch.client.opensearch._types.query_dsl;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Test;
 import org.opensearch.client.opensearch.model.ModelTestCase;
 
 public class SpanNotQueryTest extends ModelTestCase {
     @Test
     public void toBuilder() {
         SpanNotQuery origin = new SpanNotQuery.Builder().include(
-            new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(List.of()).build()).build()
-        ).exclude(new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(List.of()).build()).build()).build();
+            new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(Collections.emptyList()).build()).build()
+        ).exclude(new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(Collections.emptyList()).build()).build()).build();
         SpanNotQuery copied = origin.toBuilder().build();
 
         assertEquals(toJson(copied), toJson(origin));

java-client/src/test/java/org/opensearch/client/opensearch/_types/query_dsl/SpanOrQueryTest.java

@@ -1,14 +1,16 @@
 package org.opensearch.client.opensearch._types.query_dsl;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Test;
 import org.opensearch.client.opensearch.model.ModelTestCase;
 
 public class SpanOrQueryTest extends ModelTestCase {
     @Test
     public void toBuilder() {
         SpanOrQuery origin = new SpanOrQuery.Builder().clauses(
-            List.of(new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(List.of()).build()).build())
+            Collections.singletonList(
+                new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(Collections.emptyList()).build()).build()
+            )
         ).build();
         SpanOrQuery copied = origin.toBuilder().build();
 

java-client/src/test/java/org/opensearch/client/opensearch/_types/query_dsl/SpanQueryTest.java

@@ -1,13 +1,13 @@
 package org.opensearch.client.opensearch._types.query_dsl;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Test;
 import org.opensearch.client.opensearch.model.ModelTestCase;
 
 public class SpanQueryTest extends ModelTestCase {
     @Test
     public void toBuilder() {
-        SpanQuery origin = new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(List.of()).build()).build();
+        SpanQuery origin = new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(Collections.emptyList()).build()).build();
         SpanQuery copied = origin.toBuilder().build();
 
         assertEquals(toJson(copied), toJson(origin));

java-client/src/test/java/org/opensearch/client/opensearch/_types/query_dsl/SpanWithinQueryTest.java

@@ -1,15 +1,15 @@
 package org.opensearch.client.opensearch._types.query_dsl;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Test;
 import org.opensearch.client.opensearch.model.ModelTestCase;
 
 public class SpanWithinQueryTest extends ModelTestCase {
     @Test
     public void toBuilder() {
         SpanWithinQuery origin = new SpanWithinQuery.Builder().big(
-            new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(List.of()).build()).build()
-        ).little(new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(List.of()).build()).build()).build();
+            new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(Collections.emptyList()).build()).build()
+        ).little(new SpanQuery.Builder().spanOr(new SpanOrQuery.Builder().clauses(Collections.emptyList()).build()).build()).build();
         SpanWithinQuery copied = origin.toBuilder().build();
 
         assertEquals(toJson(copied), toJson(origin));

java-client/src/test/java/org/opensearch/client/opensearch/_types/query_dsl/TermsQueryFieldTest.java

@@ -1,14 +1,14 @@
 package org.opensearch.client.opensearch._types.query_dsl;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Test;
 import org.opensearch.client.opensearch._types.FieldValue;
 import org.opensearch.client.opensearch.model.ModelTestCase;
 
 public class TermsQueryFieldTest extends ModelTestCase {
     @Test
     public void toBuilder() {
-        TermsQueryField origin = new TermsQueryField.Builder().value(List.of(FieldValue.of("1"))).build();
+        TermsQueryField origin = new TermsQueryField.Builder().value(Collections.singletonList(FieldValue.of("1"))).build();
         TermsQueryField copied = origin.toBuilder().build();
 
         assertEquals(toJson(copied), toJson(origin));

java-client/src/test/java/org/opensearch/client/opensearch/_types/query_dsl/TermsQueryTest.java

@@ -1,6 +1,6 @@
 package org.opensearch.client.opensearch._types.query_dsl;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Test;
 import org.opensearch.client.opensearch._types.FieldValue;
 import org.opensearch.client.opensearch.model.ModelTestCase;
@@ -9,7 +9,7 @@ public class TermsQueryTest extends ModelTestCase {
     @Test
     public void toBuilder() {
         TermsQuery origin = new TermsQuery.Builder().field("field")
-            .terms(new TermsQueryField.Builder().value(List.of(FieldValue.of("1"))).build())
+            .terms(new TermsQueryField.Builder().value(Collections.singletonList(FieldValue.of("1"))).build())
             .build();
         TermsQuery copied = origin.toBuilder().build();
 

java-client/src/test/java/org/opensearch/client/opensearch/core/BulkRequestTest.java

@@ -1,6 +1,6 @@
 package org.opensearch.client.opensearch.core;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Assert;
 import org.junit.Test;
 import org.opensearch.client.opensearch.core.bulk.BulkOperation;
@@ -11,7 +11,9 @@ public class BulkRequestTest extends Assert {
     @Test
     public void toBuilder() {
         BulkRequest origin = new BulkRequest.Builder().index("index")
-            .operations(List.of(new BulkOperation.Builder().delete(new DeleteOperation.Builder().id("id").build()).build()))
+            .operations(
+                Collections.singletonList(new BulkOperation.Builder().delete(new DeleteOperation.Builder().id("id").build()).build())
+            )
             .build();
         BulkRequest copied = origin.toBuilder().build();
 

java-client/src/test/java/org/opensearch/client/opensearch/core/ClearScrollRequestTest.java

@@ -1,14 +1,14 @@
 package org.opensearch.client.opensearch.core;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Assert;
 import org.junit.Test;
 
 public class ClearScrollRequestTest extends Assert {
 
     @Test
     public void toBuilder() {
-        ClearScrollRequest origin = new ClearScrollRequest.Builder().scrollId(List.of("1")).build();
+        ClearScrollRequest origin = new ClearScrollRequest.Builder().scrollId(Collections.singletonList("1")).build();
         ClearScrollRequest copied = origin.toBuilder().build();
 
         assertEquals(copied.scrollId(), origin.scrollId());

java-client/src/test/java/org/opensearch/client/opensearch/core/MsearchRequestTest.java

@@ -1,14 +1,14 @@
 package org.opensearch.client.opensearch.core;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Assert;
 import org.junit.Test;
 
 public class MsearchRequestTest extends Assert {
 
     @Test
     public void toBuilder() {
-        MsearchRequest origin = new MsearchRequest.Builder().index("index").searches(List.of()).build();
+        MsearchRequest origin = new MsearchRequest.Builder().index("index").searches(Collections.emptyList()).build();
         MsearchRequest copied = origin.toBuilder().build();
 
         assertEquals(copied.index(), origin.index());

java-client/src/test/java/org/opensearch/client/opensearch/core/MsearchTemplateRequestTest.java

@@ -1,14 +1,16 @@
 package org.opensearch.client.opensearch.core;
 
-import java.util.List;
+import java.util.Collections;
 import org.junit.Assert;
 import org.junit.Test;
 
 public class MsearchTemplateRequestTest extends Assert {
 
     @Test
     public void toBuilder() {
-        MsearchTemplateRequest origin = new MsearchTemplateRequest.Builder().index("index").searchTemplates(List.of()).build();
+        MsearchTemplateRequest origin = new MsearchTemplateRequest.Builder().index("index")
+            .searchTemplates(Collections.emptyList())
+            .build();
         MsearchTemplateRequest copied = origin.toBuilder().build();
 
         assertEquals(copied.index(), origin.index());

java-client/src/test/java/org/opensearch/client/opensearch/core/PutIndexTemplateRequestTest.java

@@ -2,8 +2,10 @@
 
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import jakarta.json.stream.JsonParser;
 import java.io.StringReader;
-import java.util.List;
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.Map;
 import org.junit.Assert;
 import org.junit.Test;
@@ -16,15 +18,19 @@ public class PutIndexTemplateRequestTest extends Assert {
     @Test
     public void deserialize_validFieldsIncluded_RequestIsBuilt() throws JsonProcessingException {
         final JsonpMapper mapper = new JsonbJsonpMapper();
-        final Map<String, Object> indexTemplateMap = Map.of("name", "test", "index_patterns", "*", "create", true, "priority", 1);
+        final Map<String, Object> indexTemplateMap = new HashMap<>();
+        indexTemplateMap.put("name", "test");
+        indexTemplateMap.put("index_patterns", "*");
+        indexTemplateMap.put("create", true);
+        indexTemplateMap.put("priority", 1);
 
         final String indexTemplate = new ObjectMapper().writeValueAsString(indexTemplateMap);
-        final var parser = mapper.jsonProvider().createParser(new StringReader(indexTemplate));
+        final JsonParser parser = mapper.jsonProvider().createParser(new StringReader(indexTemplate));
 
         final PutIndexTemplateRequest putIndexTemplateRequest = PutIndexTemplateRequest._DESERIALIZER.deserialize(parser, mapper);
 
         assertEquals(putIndexTemplateRequest.name(), "test");
-        assertEquals(putIndexTemplateRequest.indexPatterns(), List.of("*"));
+        assertEquals(putIndexTemplateRequest.indexPatterns(), Collections.singletonList("*"));
         assertEquals((int) putIndexTemplateRequest.priority(), 1);
     }