eugenp · eric-martin · Jul 4, 2025 · Jun 11, 2025 · Jun 20, 2025
diff --git a/...core-java-string-algorithms-5/src/main/java/com/baeldung/uniqueint/StringToUniqueInt.java b/...core-java-string-algorithms-5/src/main/java/com/baeldung/uniqueint/StringToUniqueInt.java
@@ -38,12 +38,12 @@ public static int toIntByMD5(String value) {
     }
 
     public static int toIntByLookup(String value) {
-        var found = lookupMap.get(value);
+        Integer found = lookupMap.get(value);
         if (found != null) {
             return found;
         }
 
-        var intValue = counter.incrementAndGet();
+        Integer intValue = counter.incrementAndGet();
         lookupMap.put(value, intValue);
         return intValue;
     }

diff --git a/pom.xml b/pom.xml
@@ -764,6 +764,7 @@
                 <module>spring-ai</module>
                 <module>spring-ai-2</module>
         		<module>spring-ai-3</module>
+                <module>spring-ai-4</module>
                 <module>spring-ai-modules</module>
                 <module>spring-aop</module>
                 <module>spring-aop-2</module>
@@ -1196,6 +1197,7 @@
                 <module>spring-ai</module>
                 <module>spring-ai-2</module>
 				<module>spring-ai-3</module>
+                <module>spring-ai-4</module>
                 <module>spring-ai-modules</module>
                 <module>spring-aop</module>
                 <module>spring-aop-2</module>

diff --git a/spring-ai-4/pom.xml b/spring-ai-4/pom.xml
@@ -0,0 +1,119 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+   <modelVersion>4.0.0</modelVersion>
+   <artifactId>spring-ai-4</artifactId>
+   <version>0.0.1</version>
+   <packaging>jar</packaging>
+   <name>spring-ai-4</name>
+
+   <parent>
+       <groupId>com.baeldung</groupId>
+       <artifactId>parent-boot-3</artifactId>
+       <version>0.0.1-SNAPSHOT</version>
+       <relativePath>../parent-boot-3</relativePath>
+   </parent>
+
+   <repositories>
+       <repository>
+           <id>spring-milestones</id>
+           <name>Spring Milestones</name>
+           <url>https://repo.spring.io/milestone</url>
+           <snapshots>
+               <enabled>false</enabled>
+           </snapshots>
+           <releases>
+               <enabled>true</enabled>
+           </releases>
+       </repository>
+       <repository>
+           <id>spring-snapshots</id>
+           <name>Spring Snapshots</name>
+           <url>https://repo.spring.io/snapshot</url>
+           <snapshots>
+               <enabled>true</enabled>
+           </snapshots>
+           <releases>
+               <enabled>false</enabled>
+           </releases>
+       </repository>
+   </repositories>
+
+   <dependencyManagement>
+       <dependencies>
+           <dependency>
+               <groupId>org.springframework.ai</groupId>
+               <artifactId>spring-ai-bom</artifactId>
+               <version>${spring-ai.version}</version>
+               <type>pom</type>
+               <scope>import</scope>
+           </dependency>
+       </dependencies>
+   </dependencyManagement>
+
+   <dependencies>
+       <dependency>
+           <groupId>org.springframework.boot</groupId>
+           <artifactId>spring-boot-starter-web</artifactId>
+       </dependency>
+       <dependency>
+           <groupId>org.springframework.ai</groupId>
+           <artifactId>spring-ai-starter-model-openai</artifactId>
+       </dependency>
+       <dependency>
+           <groupId>org.springframework.ai</groupId>
+           <artifactId>spring-ai-model-chat-memory-repository-jdbc</artifactId>
+       </dependency>
+       <dependency>
+           <groupId>org.hsqldb</groupId>
+           <artifactId>hsqldb</artifactId>
+           <scope>runtime</scope>
+       </dependency>
+
+       <!-- Test dependencies -->
+       <dependency>
+           <groupId>org.springframework.boot</groupId>
+           <artifactId>spring-boot-starter-test</artifactId>
+           <scope>test</scope>
+       </dependency>
+   </dependencies>
+
+    <profiles>
+        <profile>
+            <id>chat-memory</id>
+            <activation>
+                <activeByDefault>true</activeByDefault>
+            </activation>
+            <properties>
+                <spring.boot.mainclass>com.baeldung.springai.memory.Application</spring.boot.mainclass>
+            </properties>
+        </profile>
+    </profiles>
+
+   <build>
+       <plugins>
+           <plugin>
+               <groupId>org.springframework.boot</groupId>
+               <artifactId>spring-boot-maven-plugin</artifactId>
+               <configuration>
+                   <mainClass>${spring.boot.mainclass}</mainClass>
+               </configuration>
+           </plugin>
+           <plugin>
+               <groupId>org.apache.maven.plugins</groupId>
+               <artifactId>maven-compiler-plugin</artifactId>
+               <configuration>
+                   <release>21</release>
+               </configuration>
+           </plugin>
+       </plugins>
+   </build>
+
+   <properties>
+       <junit-jupiter.version>5.9.0</junit-jupiter.version>
+       <spring-boot.version>3.5.0</spring-boot.version>
+       <spring-ai.version>1.0.0</spring-ai.version>
+   </properties>
+
+</project>
diff --git a/spring-ai-4/src/main/java/com/baeldung/springai/memory/Application.java b/spring-ai-4/src/main/java/com/baeldung/springai/memory/Application.java
@@ -0,0 +1,15 @@
+package com.baeldung.springai.memory;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication app = new SpringApplication(Application.class);
+        app.setAdditionalProfiles("memory");
+        app.run(args);
+    }
+
+}
diff --git a/spring-ai-4/src/main/java/com/baeldung/springai/memory/ChatConfig.java b/spring-ai-4/src/main/java/com/baeldung/springai/memory/ChatConfig.java
@@ -0,0 +1,21 @@
+package com.baeldung.springai.memory;
+
+import org.springframework.ai.chat.memory.ChatMemoryRepository;
+import org.springframework.ai.chat.memory.repository.jdbc.HsqldbChatMemoryRepositoryDialect;
+import org.springframework.ai.chat.memory.repository.jdbc.JdbcChatMemoryRepository;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.jdbc.core.JdbcTemplate;
+
+@Configuration
+public class ChatConfig {
+
+    @Bean
+    public ChatMemoryRepository getChatMemoryRepository(JdbcTemplate jdbcTemplate) {
+        return JdbcChatMemoryRepository.builder()
+                .jdbcTemplate(jdbcTemplate)
+                .dialect(new HsqldbChatMemoryRepositoryDialect())
+                .build();
+    }
+
+}
diff --git a/spring-ai-4/src/main/java/com/baeldung/springai/memory/ChatController.java b/spring-ai-4/src/main/java/com/baeldung/springai/memory/ChatController.java
@@ -0,0 +1,25 @@
+package com.baeldung.springai.memory;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RestController;
+
+import javax.validation.Valid;
+
+@RestController
+public class ChatController {
+
+    private final ChatService chatService;
+
+    public ChatController(ChatService chatService) {
+        this.chatService = chatService;
+    }
+
+    @PostMapping("/chat")
+    public ResponseEntity<String> chat(@RequestBody @Valid ChatRequest request) {
+        String response = chatService.chat(request.getPrompt());
+        return ResponseEntity.ok(response);
+    }
+
+}
diff --git a/spring-ai-4/src/main/java/com/baeldung/springai/memory/ChatRequest.java b/spring-ai-4/src/main/java/com/baeldung/springai/memory/ChatRequest.java
@@ -0,0 +1,18 @@
+package com.baeldung.springai.memory;
+
+import javax.validation.constraints.NotNull;
+
+public class ChatRequest {
+
+    @NotNull
+    private String prompt;
+
+    public String getPrompt() {
+        return prompt;
+    }
+
+    public void setPrompt(String prompt) {
+        this.prompt = prompt;
+    }
+
+}
diff --git a/spring-ai-4/src/main/java/com/baeldung/springai/memory/ChatService.java b/spring-ai-4/src/main/java/com/baeldung/springai/memory/ChatService.java
@@ -0,0 +1,38 @@
+package com.baeldung.springai.memory;
+
+import org.springframework.ai.chat.client.ChatClient;
+import org.springframework.ai.chat.client.advisor.MessageChatMemoryAdvisor;
+import org.springframework.ai.chat.memory.ChatMemory;
+import org.springframework.ai.chat.model.ChatModel;
+import org.springframework.stereotype.Component;
+import org.springframework.web.context.annotation.SessionScope;
+
+import java.util.UUID;
+
+@Component
+@SessionScope
+public class ChatService {
+
+    private final ChatClient chatClient;
+    private final String conversationId;
+
+    public ChatService(ChatModel chatModel, ChatMemory chatMemory) {
+        this.chatClient = ChatClient.builder(chatModel)
+                .defaultAdvisors(MessageChatMemoryAdvisor.builder(chatMemory).build())
+                .build();
+        this.conversationId = UUID.randomUUID().toString();
+    }
+
+    public String getConversationId() {
+        return conversationId;
+    }
+
+    public String chat(String prompt) {
+        return chatClient.prompt()
+                .user(userMessage -> userMessage.text(prompt))
+                .advisors(a -> a.param(ChatMemory.CONVERSATION_ID, conversationId))
+                .call()
+                .content();
+    }
+
+}
diff --git a/spring-ai-4/src/main/resources/application-memory.yml b/spring-ai-4/src/main/resources/application-memory.yml
@@ -0,0 +1,15 @@
+spring:
+  ai:
+    openai:
+      api-key: "<YOUR-API-KEY>"
+
+  datasource:
+    url: jdbc:hsqldb:mem:chatdb
+    driver-class-name: org.hsqldb.jdbc.JDBCDriver
+    username: sa
+    password:
+
+  sql:
+    init:
+      mode: always
+      schema-locations: classpath:org/springframework/ai/chat/memory/repository/jdbc/schema-hsqldb.sql
diff --git a/spring-ai-4/src/main/resources/logback.xml b/spring-ai-4/src/main/resources/logback.xml
@@ -0,0 +1,15 @@
+<configuration>
+    <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>[%d{yyyy-MM-dd HH:mm:ss}] [%p] [%c{1}] - %m%n</pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="CONSOLE" />
+    </root>
+
+    <logger name="org.springframework" level="INFO" additivity="false">
+        <appender-ref ref="CONSOLE" />
+    </logger>
+</configuration>
diff --git a/spring-ai-4/src/test/java/com/baeldung/springai/memory/ChatServiceLiveTest.java b/spring-ai-4/src/test/java/com/baeldung/springai/memory/ChatServiceLiveTest.java
@@ -0,0 +1,39 @@
+package com.baeldung.springai.memory;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.ai.chat.memory.ChatMemory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.ActiveProfiles;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@SpringBootTest
+@ActiveProfiles("memory")
+class ChatServiceLiveTest {
+
+    private static final String PROMPT_1ST = "Tell me a joke";
+    private static final String PROMPT_2ND = "Tell me another one";
+
+    @Autowired
+    private ChatMemory chatMemory;
+
+    @Autowired
+    private ChatService chatService;
+
+    @Test
+    void whenChatServiceIsCalledTwice_thenChatMemoryHasCorrectNumberOfEntries() {
+        String conversationId = chatService.getConversationId();
+
+        // 1st request
+        String response1 = chatService.chat(PROMPT_1ST);
+        assertThat(response1).isNotEmpty();
+        assertThat(chatMemory.get(conversationId)).hasSize(2);
+
+        // 2nd request
+        String response2 = chatService.chat(PROMPT_2ND);
+        assertThat(response2).isNotEmpty();
+        assertThat(chatMemory.get(conversationId)).hasSize(4);
+    }
+
+}