From cf41b9711fdb63491c50af9752b5d853e6267b99 Mon Sep 17 00:00:00 2001
From: Oliver Drotbohm <odrotbohm@pivotal.io>
Date: Mon, 15 Jun 2020 22:09:39 +0200
Subject: [PATCH] DATACMNS-1743 - Fix lazy repository lookups in
 DomainClassConverter.

We now eagerly register DomainClassConverter as converter with the ConversionService in the web setup. We also refrain from explicitly registering the traget converters with the ConversionService as that might trigger a ConcurrentModificationException if called during an iteration over the converters in the first place. As DomainClassConverter registers itself for all ConvertiblePairs and delegates to the individual converters anyway.
---
 .../data/repository/support/DomainClassConverter.java |  4 +---
 .../support/DomainClassConverterUnitTests.java        | 11 +++++++++++
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/main/java/org/springframework/data/repository/support/DomainClassConverter.java b/src/main/java/org/springframework/data/repository/support/DomainClassConverter.java
index 01080cdfb..828c5ff3a 100644
--- a/src/main/java/org/springframework/data/repository/support/DomainClassConverter.java
+++ b/src/main/java/org/springframework/data/repository/support/DomainClassConverter.java
@@ -62,6 +62,7 @@ public class DomainClassConverter<T extends ConversionService & ConverterRegistr
 		Assert.notNull(conversionService, "ConversionService must not be null!");
 
 		this.conversionService = conversionService;
+		this.conversionService.addConverter(this);
 	}
 
 	/*
@@ -112,10 +113,7 @@ public class DomainClassConverter<T extends ConversionService & ConverterRegistr
 			Repositories repositories = new Repositories(context);
 
 			this.toEntityConverter = Optional.of(new ToEntityConverter(repositories, conversionService));
-			this.toEntityConverter.ifPresent(it -> conversionService.addConverter(it));
-
 			this.toIdConverter = Optional.of(new ToIdConverter(repositories, conversionService));
-			this.toIdConverter.ifPresent(it -> conversionService.addConverter(it));
 
 			return repositories;
 		});
diff --git a/src/test/java/org/springframework/data/repository/support/DomainClassConverterUnitTests.java b/src/test/java/org/springframework/data/repository/support/DomainClassConverterUnitTests.java
index 48f4368a3..c6cbed87f 100755
--- a/src/test/java/org/springframework/data/repository/support/DomainClassConverterUnitTests.java
+++ b/src/test/java/org/springframework/data/repository/support/DomainClassConverterUnitTests.java
@@ -34,6 +34,7 @@ import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.GenericApplicationContext;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.convert.TypeDescriptor;
+import org.springframework.core.convert.support.ConfigurableConversionService;
 import org.springframework.core.convert.support.DefaultConversionService;
 import org.springframework.data.repository.CrudRepository;
 import org.springframework.data.repository.core.support.DummyRepositoryFactoryBean;
@@ -189,6 +190,16 @@ public class DomainClassConverterUnitTests {
 		assertThat(toIdConverter).map(it -> it.matches(SUB_USER_TYPE, target)).hasValue(false);
 	}
 
+	@Test // DATACMNS-1743
+	public void registersConvertersOnConversionService() {
+
+		ConfigurableConversionService conversionService = new DefaultConversionService();
+		DomainClassConverter<?> converter = new DomainClassConverter<>(conversionService);
+		converter.setApplicationContext(initContextWithRepo());
+
+		assertThat(conversionService.canConvert(String.class, User.class)).isTrue();
+	}
+
 	private ApplicationContext initContextWithRepo() {
 
 		BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(DummyRepositoryFactoryBean.class);