Example button handler code

pi4j-spring-boot-starter-sample-app/src/main/java/com/pi4j/spring/boot/sample/app/controller/Pi4JController.java

@@ -3,6 +3,8 @@
 import com.pi4j.context.Context;
 import com.pi4j.io.gpio.digital.DigitalOutput;
 import com.pi4j.io.gpio.digital.DigitalState;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -13,12 +15,14 @@
 @RequestMapping("/api/pi4j/")
 public class Pi4JController {
 
+    private static final Logger logger = LoggerFactory.getLogger(Pi4JController.class);
     private static final int PIN_LED = 22; // PIN 15 = BCM 22
-    private DigitalOutput led;
+    private final DigitalOutput led;
 
     public Pi4JController(@Autowired Context pi4j) {
         // LED example is based on https://www.pi4j.com/getting-started/minimal-example-application/
         led = pi4j.digitalOutput().create(PIN_LED);
+        logger.info("LED initialized on pin {}", PIN_LED);
     }
 
     @GetMapping("/led/{status}")

pi4j-spring-boot-starter-sample-app/src/main/java/com/pi4j/spring/boot/sample/app/service/Pi4JService.java

@@ -0,0 +1,34 @@
+package com.pi4j.spring.boot.sample.app.service;
+
+import com.pi4j.context.Context;
+import com.pi4j.io.gpio.digital.DigitalInput;
+import com.pi4j.io.gpio.digital.DigitalStateChangeEvent;
+import com.pi4j.io.gpio.digital.PullResistance;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+@Service
+public class Pi4JService {
+
+    private static final Logger logger = LoggerFactory.getLogger(Pi4JService.class);
+    private static final int PIN_BUTTON = 24; // PIN 18 = BCM 24
+
+    public Pi4JService(@Autowired Context pi4j) {
+        // Button example is based on https://www.pi4j.com/getting-started/minimal-example-application/
+        var buttonConfig = DigitalInput.newConfigBuilder(pi4j)
+                .id("button")
+                .name("Press button")
+                .address(PIN_BUTTON)
+                .pull(PullResistance.PULL_DOWN)
+                .debounce(3000L);
+        var button = pi4j.create(buttonConfig);
+        button.addListener(e -> handleButtonChange(e));
+        logger.info("Button initialized on pin {}", PIN_BUTTON);
+    }
+
+    private void handleButtonChange(DigitalStateChangeEvent e) {
+        logger.info("Button state changed to {}", e.state());
+    }
+}