diff --git a/src/main/java/net/lamgc/oracle/sentry/script/groovy/trigger/InstanceStateWatchTrigger.java b/src/main/java/net/lamgc/oracle/sentry/script/groovy/trigger/InstanceStateWatchTrigger.java
new file mode 100644
index 0000000..c7f65e0
--- /dev/null
+++ b/src/main/java/net/lamgc/oracle/sentry/script/groovy/trigger/InstanceStateWatchTrigger.java
@@ -0,0 +1,286 @@
+package net.lamgc.oracle.sentry.script.groovy.trigger;
+
+import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import com.oracle.bmc.core.ComputeClient;
+import com.oracle.bmc.core.model.Instance;
+import com.oracle.bmc.core.requests.GetInstanceRequest;
+import groovy.lang.Closure;
+import net.lamgc.oracle.sentry.ComputeInstanceManager;
+import net.lamgc.oracle.sentry.oci.compute.ComputeInstance;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.atomic.AtomicReference;
+
+/**
+ * 实例状态监视触发器.
+ * 通过轮询实例状态, 当状态为指定的状态时将触发回调执行操作.
+ *
吐槽: 换个地方轮询(xs).
+ * @author LamGC
+ */
+@TriggerName("InstanceStateWatcher")
+public class InstanceStateWatchTrigger implements GroovyTrigger {
+
+ private final static Logger log = LoggerFactory.getLogger(InstanceStateWatchTrigger.class);
+ private final static ThreadFactory THREAD_FACTORY = new ThreadFactoryBuilder()
+ .setDaemon(true)
+ .setNameFormat("Thread-InstanceStatePolling-%d")
+ .build();
+
+ private final Set instances = new HashSet<>();
+ private final AtomicReference instanceManager = new AtomicReference<>();
+ private final AtomicReference pollingThreadReference = new AtomicReference<>();
+ private final Set targetStates = new HashSet<>();
+ private long interval = 5000;
+
+ /**
+ * 设置 {@link ComputeInstanceManager}.
+ * 设置计算实例管理器以实现部分功能.
+ * @param instanceManager 实例管理器.
+ */
+ public void setInstanceManager(ComputeInstanceManager instanceManager) {
+ this.instanceManager.set(instanceManager);
+ }
+
+ /**
+ * 添加所有实例.
+ *
调用前需设置实例管理器.
+ */
+ public void allInstances() {
+ addInstance(instanceManager.get().getComputeInstances());
+ }
+
+ /**
+ * 添加需要监控的实例.
+ *
调用前需设置实例管理器.
+ * @param instanceId 要添加的实例 Id.(注意不是实例名称.)
+ */
+ public void addInstance(String instanceId) {
+ this.instances.add(instanceManager.get().getComputeInstanceById(instanceId));
+ }
+
+ /**
+ * 添加需要监控的实例.
+ * @param instance 实例对象.
+ */
+ public void addInstance(ComputeInstance instance) {
+ this.instances.add(instance);
+ }
+
+ /**
+ * 添加需要监控的实例.
+ * @param instances 实例集合.
+ */
+ public void addInstance(Set instances) {
+ this.instances.addAll(instances);
+ }
+
+ /**
+ * 设置监控间隔.
+ * 该间隔是每轮查询之间的间隔, 并非查询每个实例的间隔. Oracle 对该接口的请求限制很宽松, 且单个帐号的实例有限, 故不再设置查询间隔.
+ * @param interval 间隔时常, 单位: 毫秒.
+ */
+ public void interval(long interval) {
+ this.interval = interval;
+ }
+
+ /**
+ * 要检查的状态.
+ *
当实例处于指定状态时将触发回调.
+ * @param state 状态名.
+ */
+ public void state(String state) {
+ targetStates.add(getState(state));
+ }
+
+ /**
+ * 要检查的状态.
+ *
当实例处于指定状态时将触发回调.
+ * @param states 状态集合.
+ */
+ public void state(String[] states) {
+ Set stateSet = new HashSet<>();
+ for (String state : states) {
+ stateSet.add(getState(state));
+ }
+ targetStates.addAll(stateSet);
+ }
+
+ /**
+ * 添加所有状态.
+ * 所有状态都会触发回调函数.
+ */
+ public void allStates() {
+ targetStates.addAll(Set.of(Instance.LifecycleState.values()));
+ }
+
+ /**
+ * 通过状态名获取对应的 {@link Instance.LifecycleState}.
+ * @param state 状态名.
+ * @return 返回对应值.
+ * @throws IllegalArgumentException 当无法获取指定状态对象时抛出该异常.
+ */
+ private Instance.LifecycleState getState(String state) {
+ try {
+ return LifecycleStateMapping.valueOf(state.toUpperCase()).target;
+ } catch (IllegalArgumentException e) {
+ try {
+ return Instance.LifecycleState.valueOf(toFirstCharUpperCase(state));
+ } catch (IllegalArgumentException ex) {
+ throw new IllegalArgumentException("Invalid target state: " + state);
+ }
+ }
+ }
+
+ @Override
+ public synchronized void run(final Closure callback) {
+ if (pollingThreadReference.get() != null) {
+ throw new IllegalStateException("Attempting to start multiple check threads repeatedly, which is not allowed.");
+ }
+ if (targetStates.isEmpty()) {
+ throw new IllegalArgumentException("The target status has not been set.");
+ }
+ if (instances.isEmpty()) {
+ log.warn("尚未设置任何需监视的实例, 已跳过对触发器的启动.", new IllegalStateException("未设置任何需要监视的实例."));
+ return;
+ }
+
+ Thread newPollingThread = THREAD_FACTORY.newThread(new PollingTask(instances, targetStates, callback, interval));
+ newPollingThread.start();
+ pollingThreadReference.set(newPollingThread);
+ }
+
+ @Override
+ public synchronized void shutdown() {
+ if (pollingThreadReference.get() == null) {
+ return;
+ }
+ // 合规的，用于停止线程的方法。（笑）（无歧义）
+ Thread pollingThread = pollingThreadReference.get();
+ pollingThread.interrupt();
+ pollingThreadReference.set(null);
+ }
+
+ /**
+ * 首字母大写.
+ * @param str 要处理的单词.
+ * @return 如果首字母非大写, 就转换成大写.
+ */
+ private static String toFirstCharUpperCase(String str) {
+ char firstChar = str.charAt(0);
+ if (!Character.isUpperCase(firstChar)) {
+ return Character.toUpperCase(firstChar) + str.substring(1);
+ }
+ return str;
+ }
+
+ /**
+ * 轮询任务.
+ */
+ private static class PollingTask implements Runnable {
+
+ private final Set instances;
+ private final Set targetStates;
+ private final Closure callback;
+ private final long interval;
+ private final Map lastStateMap = new ConcurrentHashMap<>();
+
+ private PollingTask(Set instances, Set targetStates,
+ Closure callback, long interval) {
+ this.instances = instances;
+ this.targetStates = targetStates;
+ this.callback = callback;
+ if (interval <= 0) {
+ throw new IllegalArgumentException("Interval cannot be less than or equal to 0.");
+ }
+ this.interval = interval;
+ }
+
+ @SuppressWarnings("BusyWait")
+ @Override
+ public void run() {
+ while (!Thread.interrupted()) {
+ try {
+ // 并非 BusyWait, 而是延迟操作.
+ Thread.sleep(interval);
+ } catch (InterruptedException e) {
+ break;
+ }
+ log.trace("正在开始新一轮实例状态检查...");
+ for (ComputeInstance instance : instances) {
+ ComputeClient computeClient = instance.getFromAccount().clients().compute();
+ Instance instanceInfo;
+ try {
+ instanceInfo = computeClient.getInstance(GetInstanceRequest.builder()
+ .instanceId(instance.getInstanceId())
+ .build()).getInstance();
+ } catch (Exception e) {
+ if (e.getCause() instanceof InterruptedException) {
+ Thread.currentThread().interrupt();
+ break;
+ }
+ if (log.isDebugEnabled()) {
+ log.error("获取实例状态失败.", e);
+ } else {
+ log.error("获取实例状态失败(详情请打开 Debug 级别): {}:{}", e.getClass().getName(), e.getMessage());
+ }
+ continue;
+ }
+ Instance.LifecycleState lastState = lastStateMap.get(instance);
+ if (targetStates.contains(instanceInfo.getLifecycleState()) &&
+ instanceInfo.getLifecycleState() != lastState) {
+ try {
+ callback.call(new InstanceStateChangeEvent(instance,
+ lastState != null ? lastState.name() : null,
+ instanceInfo.getLifecycleState().name()));
+ } catch (Exception e) {
+ log.error("实例状态事件处理时发生未捕获异常.", e);
+ }
+ }
+ lastStateMap.put(instance, instanceInfo.getLifecycleState());
+ }
+ log.trace("实例状态检查已结束.");
+ }
+ }
+ }
+
+ /**
+ * 一个 Oracle 实例状态枚举的映射枚举类.
+ */
+ @SuppressWarnings({"AlibabaEnumConstantsMustHaveComment", "unused"})
+ private enum LifecycleStateMapping {
+ MOVING(Instance.LifecycleState.Moving),
+ PROVISIONING(Instance.LifecycleState.Provisioning),
+ RUNNING(Instance.LifecycleState.Running),
+ STARTING(Instance.LifecycleState.Starting),
+ STOPPING(Instance.LifecycleState.Stopping),
+ STOPPED(Instance.LifecycleState.Stopped),
+ CREATING_IMAGE(Instance.LifecycleState.CreatingImage),
+ TERMINATING(Instance.LifecycleState.Terminating),
+ TERMINATED(Instance.LifecycleState.Terminated);
+
+ private final Instance.LifecycleState target;
+
+ LifecycleStateMapping(Instance.LifecycleState target) {
+ this.target = target;
+ }
+ }
+
+ /**
+ * 实例状态变更事件.
+ * @param instance 相关实例.
+ * @param oldState 旧状态, 当监视器第一次查询即触发时, 该值为 {@code null}.
+ * @param newState 新状态.
+ */
+ public static record InstanceStateChangeEvent(
+ ComputeInstance instance,
+ String oldState,
+ String newState
+ ) {}
+
+}
diff --git a/src/main/resources/META-INF/services/net.lamgc.oracle.sentry.script.groovy.trigger.GroovyTrigger b/src/main/resources/META-INF/services/net.lamgc.oracle.sentry.script.groovy.trigger.GroovyTrigger
index 7fd6e8f..805a13b 100644
--- a/src/main/resources/META-INF/services/net.lamgc.oracle.sentry.script.groovy.trigger.GroovyTrigger
+++ b/src/main/resources/META-INF/services/net.lamgc.oracle.sentry.script.groovy.trigger.GroovyTrigger
@@ -1,2 +1,3 @@
net.lamgc.oracle.sentry.script.groovy.trigger.OnceTrigger
net.lamgc.oracle.sentry.script.groovy.trigger.TimerTrigger
+net.lamgc.oracle.sentry.script.groovy.trigger.InstanceStateWatchTrigger