From fb944b3b984db76490e1c3c97b4c9b6ebea05ac8 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 0c8282d86..29ae01b8c 100755
--- a/src/test/java/org/springframework/data/repository/support/DomainClassConverterUnitTests.java
+++ b/src/test/java/org/springframework/data/repository/support/DomainClassConverterUnitTests.java
@@ -36,6 +36,7 @@ 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;
@@ -192,6 +193,16 @@ class DomainClassConverterUnitTests {
 		assertThat(toIdConverter).map(it -> it.matches(SUB_USER_TYPE, target)).hasValue(false);
 	}
 
+	@Test // DATACMNS-1743
+	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);