Failing test for SqlServer

ebean-test/src/test/java/org/tests/json/TestDbJsonLength.java

@@ -0,0 +1,52 @@
+package org.tests.json;
+
+import io.ebean.DB;
+import io.ebean.DataIntegrityException;
+import org.assertj.core.api.SoftAssertions;
+import org.junit.jupiter.api.Test;
+import org.tests.model.json.EBasicJsonMap;
+
+import java.util.Map;
+
+class TestDbJsonLength {
+
+
+    /**
+   * The property 'EBasicJsonMap.content' is annotated with @DbJson(length=5000). So we assume, that we cannot save Json-objects
+   * where the serialized form exceed that limit and we would expect an error on save.
+   * The length check works for platforms like h2, as H2 uses a 'varchar(5000)'. So it is impossible to save such long jsons,
+   * but it won't work for SqlServer, as here 'nvarchar(max)' is used. No validation happens at DB level and you might get very
+   * large Json objects in your database. This mostly happens unintentionally (programming error, misconfiguration)
+   * So they are in the database and they cannot be accessed by ebean any more, because there are new limits in Jackson:
+   * - Max 5 Meg per string in 2.15.0
+   * - Max 20 Meg per string in 2.15.1
+   * see https://github.com/FasterXML/jackson-core/issues/1014
+   */
+  @Test
+  void testLongString() {
+    // s is so big, that it could not be deserialized by jackson
+    String s = new String(new char[20_000_001]).replace('\0', 'x');
+
+    EBasicJsonMap bean = new EBasicJsonMap();
+    bean.setName("b1");
+    bean.setContent(Map.of("string", s));
+
+    SoftAssertions softly = new SoftAssertions();
+
+    softly.assertThatThrownBy(() -> {
+      DB.save(bean);
+    }).isInstanceOf(DataIntegrityException.class);
+
+
+    if (bean.getId() != null) {
+      // we expect, that we could NOT save the bean, but this is not true for sqlServer.
+      // we will get a javax.persistence.PersistenceException: Error loading on org.tests.model.json.EBasicJsonMap.content
+      // when we try to load the bean back from DB
+      DB.find(EBasicJsonMap.class, bean.getId());
+    }
+
+    softly.assertAll();
+
+  }
+
+}

ebean-test/src/test/java/org/tests/model/json/EBasicJsonMap.java

@@ -18,7 +18,7 @@ public class EBasicJsonMap {
 
   String name;
 
-  @DbJson
+  @DbJson(length = 5000)
   Map<String, Object> content;
 
   @OneToMany(mappedBy = "owner", cascade = CascadeType.ALL)

pom.xml

@@ -42,7 +42,7 @@
     <nexus.staging.keepStagingRepositoryOnFailure>true</nexus.staging.keepStagingRepositoryOnFailure>
     <nexus.staging.skipStagingRepositoryClose>true</nexus.staging.skipStagingRepositoryClose>
     <nexus.staging.autoReleaseAfterClose>false</nexus.staging.autoReleaseAfterClose>
-    <jackson.version>2.15.0</jackson.version>
+    <jackson.version>2.15.2</jackson.version>
     <h2database.version>2.1.214</h2database.version>
     <ebean-persistence-api.version>3.0</ebean-persistence-api.version>
     <ebean-types.version>3.0</ebean-types.version>