Moved the code samples for BeanDefinitionOverrideException to a new module.

spring-boot-modules/spring-boot-exceptions/src/test/java/com/baeldung/beandefinitionoverrideexception/SpringBootBeanDefinitionOverrideExceptionIntegrationTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.beandefinitionoverrideexception;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.ApplicationContext;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = {TestConfiguration1.class, TestConfiguration2.class}, properties = {"spring.main.allow-bean-definition-overriding=true"})
+public class SpringBootBeanDefinitionOverrideExceptionIntegrationTest {
+
+    @Autowired
+    private ApplicationContext applicationContext;
+
+    @Test
+    public void whenBeanOverridingAllowed_thenTestBean2OverridesTestBean1() {
+        Object testBean = applicationContext.getBean("testBean");
+
+        assertThat(testBean.getClass()).isEqualTo(TestConfiguration2.TestBean2.class);
+    }
+}

spring-boot-modules/spring-boot-exceptions/src/test/java/com/baeldung/beandefinitionoverrideexception/TestConfiguration1.java

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+package com.baeldung.beandefinitionoverrideexception;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class TestConfiguration1 {
+
+    class TestBean1 {
+
+        private String name;
+
+        public String getName() {
+            return name;
+        }
+
+        public void setName(String name) {
+            this.name = name;
+        }
+    }
+
+    @Bean
+    public TestBean1 testBean() {
+        return new TestBean1();
+    }
+
+}

spring-boot-modules/spring-boot-exceptions/src/test/java/com/baeldung/beandefinitionoverrideexception/TestConfiguration2.java

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+package com.baeldung.beandefinitionoverrideexception;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class TestConfiguration2 {
+
+    class TestBean2 {
+
+        private String name;
+
+        public String getName() {
+            return name;
+        }
+
+        public void setName(String name) {
+            this.name = name;
+        }
+
+    }
+
+    @Bean
+    public TestBean2 testBean() {
+        return new TestBean2();
+    }
+
+}

spring-boot-modules/spring-boot-exceptions/src/test/resources/logback-test.xml

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+<configuration>
+    <include resource="/org/springframework/boot/logging/logback/base.xml"/>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+    <root level="error">
+        <appender-ref ref="STDOUT"/>
+    </root>
+    <logger name="com.baeldung.testloglevel" level="debug"/>
+</configuration>

spring-boot-modules/spring-boot-exceptions/src/test/resources/org/baeldung/boot/expected.json

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+{
+	"id":3,
+	"name":"Foo_Name_3"
+}