Spring Boot Setup for Google GenAI

Dependencies (pom.xml):

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.4.12</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.codeWithNeha</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>
    <url/>
    <licenses>
        <license/>
    </licenses>
    <developers>
        <developer/>
    </developers>
    <scm>
        <connection/>
        <developerConnection/>
        <tag/>
        <url/>
    </scm>
    <properties>
        <java.version>17</java.version>
        <spring-ai.version>1.1.0</spring-ai.version>
    </properties>
    <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-starter-model-google-genai</artifactId>
      <version>1.1.0</version>
    </dependency>
    <dependency>
      <groupId>org.springdoc</groupId>
      <artifactId>springdoc-openapi-starter-webmvc-ui</artifactId>
      <version>2.0.4</version>
    </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <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>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

application.yml configuration:

spring:
  application:
    name: demo

  ai:
    model:
      chat: google-genai
    google:
      genai:
        api-key: YOUR_API_KEY_HERE  # replace with your actual key

server:
  port: 9191

---

2. Chat Service Layer

Your ChatService class is responsible for interacting with Google GenAI via Spring AI:

package com.codeWithNeha.demo.service;

import org.springframework.ai.chat.client.ChatClient;
import org.springframework.stereotype.Service;

@Service
public class ChatService {

    private final ChatClient chatClient;

    public ChatService(ChatClient.Builder gemini) {
        this.chatClient = gemini.build(); // Build client using Builder
    }

    public String ask(String prompt) {
        // Sends prompt to GenAI and gets response
        return chatClient.prompt(prompt).call().content();
    }
}

Notes:

• ChatClient.Builder is injected by Spring Boot automatically if Spring AI is configured.

• chatClient.prompt(prompt).call() sends your text and retrieves the AI response.

• .content() extracts the text from the AI response.

---

3. Controller Layer

Your ChatController exposes an API endpoint to call ChatService:

package com.codeWithNeha.demo.controller;

import com.codeWithNeha.demo.service.ChatService;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api/ai")
public class ChatController {

    private final ChatService chatService;

    public ChatController(ChatService chatService) {
        this.chatService = chatService;
    }

    @GetMapping("/chat")
    public String chat(@RequestParam String prompt) {
        return chatService.ask(prompt);
    }
}

Notes:

• Access the endpoint via:

    GET http://localhost:9191/api/ai/chat?prompt=Hello
  

• The prompt parameter is sent to the AI and the response is returned as plain text.

• Controller uses dependency injection to get ChatService.

As I have not bought api key and billing issue response is 500