Add Spring Boot example app with auto-configuration demo

- New subproject: python-embed-examples/spring-boot-example/
- REST controller (/eval, /exec, /info) using auto-configured PythonEmbed bean
- Actuator health endpoint with PythonEmbedHealthIndicator
- SINGLE mode (application.yml) and POOL mode (application-pool.yml) profiles
- Updated examples settings.gradle to include spring-boot-starter and new subproject

Author: howtis

python-embed-examples/settings.gradle

@@ -3,6 +3,8 @@ rootProject.name = 'python-embed-examples'
 includeBuild '../python-embed-gradle-plugin'
 include ':python-embed-runtime'
 project(':python-embed-runtime').projectDir = file('../python-embed-runtime')
+include ':python-embed-spring-boot-starter'
+project(':python-embed-spring-boot-starter').projectDir = file('../python-embed-spring-boot-starter')
 
 include 'basic-eval'
 include 'numpy-basic'
@@ -16,3 +18,4 @@ include 'object-handle'
 include 'health-monitor'
 include 'batch-operations'
 include 'pandas-dataframe'
+include 'spring-boot-example'

python-embed-examples/spring-boot-example/build.gradle

@@ -0,0 +1,20 @@
+plugins {
+    id 'io.github.howtis.python-embed'
+    id 'org.springframework.boot' version '3.3.5'
+    id 'io.spring.dependency-management' version '1.1.6'
+}
+
+application {
+    mainClass = 'io.github.howtis.pythonembed.examples.SpringBootExampleApplication'
+}
+
+dependencies {
+    implementation project(':python-embed-runtime')
+    implementation project(':python-embed-spring-boot-starter')
+    implementation 'org.springframework.boot:spring-boot-starter-web'
+    implementation 'org.springframework.boot:spring-boot-starter-actuator'
+}
+
+pythonEmbed {
+    packages = ['msgpack']
+}

python-embed-examples/spring-boot-example/src/main/java/io/github/howtis/pythonembed/examples/PythonController.java

@@ -0,0 +1,71 @@
+package io.github.howtis.pythonembed.examples;
+
+import io.github.howtis.pythonembed.PythonEmbed;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Map;
+
+/**
+ * REST controller demonstrating auto-configured {@link PythonEmbed} bean
+ * injection and usage.
+ */
+@RestController
+public class PythonController {
+
+    private final PythonEmbed pythonEmbed;
+
+    public PythonController(PythonEmbed pythonEmbed) {
+        this.pythonEmbed = pythonEmbed;
+    }
+
+    /**
+     * Evaluates a Python expression and returns the result.
+     *
+     * <pre>
+     * GET /eval?expr=2+2        → 4
+     * GET /eval?expr=len('abc') → 3
+     * </pre>
+     */
+    @GetMapping("/eval")
+    public Map<String, Object> eval(@RequestParam String expr) {
+        String result;
+        try {
+            var value = pythonEmbed.eval(expr);
+            result = value.toJson();
+        } catch (Exception e) {
+            result = "Error: " + e.getMessage();
+        }
+        return Map.of("expression", expr, "result", result);
+    }
+
+    /**
+     * Executes a Python statement.
+     *
+     * <pre>
+     * GET /exec?stmt=x=42
+     * GET /eval?expr=x          → 42  (shared namespace)
+     * </pre>
+     */
+    @GetMapping("/exec")
+    public Map<String, Object> exec(@RequestParam String stmt) {
+        try {
+            pythonEmbed.exec(stmt);
+            return Map.of("statement", stmt, "status", "ok");
+        } catch (Exception e) {
+            return Map.of("statement", stmt, "status", "error", "message", e.getMessage());
+        }
+    }
+
+    /**
+     * Returns Python interpreter information.
+     */
+    @GetMapping("/info")
+    public Map<String, String> info() {
+        pythonEmbed.exec("import sys");
+        String version = pythonEmbed.eval("sys.version").asString();
+        String executable = pythonEmbed.eval("sys.executable").asString();
+        return Map.of("version", version, "executable", executable);
+    }
+}

python-embed-examples/spring-boot-example/src/main/java/io/github/howtis/pythonembed/examples/SpringBootExampleApplication.java

@@ -0,0 +1,35 @@
+package io.github.howtis.pythonembed.examples;
+
+import io.github.howtis.pythonembed.PythonEmbed;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+/**
+ * Demonstrates Spring Boot auto-configuration for python-embed.
+ *
+ * <p>Starts a web server with a REST controller ({@link PythonController})
+ * and Actuator health endpoint backed by {@code PythonEmbedHealthIndicator}.
+ */
+@SpringBootApplication
+public class SpringBootExampleApplication {
+
+    private static final Logger log = LoggerFactory.getLogger(SpringBootExampleApplication.class);
+
+    public static void main(String[] args) {
+        SpringApplication.run(SpringBootExampleApplication.class, args);
+    }
+
+    @Bean
+    CommandLineRunner demo(PythonEmbed pythonEmbed) {
+        return args -> {
+            log.info("Auto-configured PythonEmbed bean: {}", pythonEmbed);
+            pythonEmbed.exec("import sys");
+            log.info("Python version: {}", pythonEmbed.eval("sys.version").asString());
+            log.info("Ping: {}", pythonEmbed.ping());
+        };
+    }
+}

python-embed-examples/spring-boot-example/src/main/resources/application-pool.yml

@@ -0,0 +1,17 @@
+python-embed:
+  mode: POOL
+  pool:
+    min: 2
+    max: 4
+    idle-timeout: 60s
+    health-check-interval: 30s
+    close-timeout: 10s
+
+management:
+  endpoint:
+    health:
+      show-details: always
+  endpoints:
+    web:
+      exposure:
+        include: health,info

python-embed-examples/spring-boot-example/src/main/resources/application.yml

@@ -0,0 +1,11 @@
+python-embed:
+  mode: SINGLE
+
+management:
+  endpoint:
+    health:
+      show-details: always
+  endpoints:
+    web:
+      exposure:
+        include: health,info