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@@ -1,152 +0,0 @@
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-package com.jeeplus.modules.centerservice.config;
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-
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-import javax.servlet.ServletContextEvent;
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-import javax.servlet.ServletContextListener;
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-import javax.servlet.annotation.WebListener;
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-import java.lang.management.ManagementFactory;
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-import java.lang.management.MemoryPoolMXBean;
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-import java.lang.management.MemoryUsage;
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-import java.time.LocalDateTime;
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-import java.time.LocalTime;
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-import java.time.temporal.ChronoUnit;
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-import java.util.List;
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-import java.util.concurrent.Executors;
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-import java.util.concurrent.ScheduledExecutorService;
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-import java.util.concurrent.TimeUnit;
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-
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-@WebListener
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-public class GcServletListener implements ServletContextListener {
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-
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- private ScheduledExecutorService scheduler;
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-
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- @Override
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- public void contextInitialized(ServletContextEvent sce) {
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- scheduler = Executors.newScheduledThreadPool(1);
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- System.out.println("✅ GC 任务已启动");
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-
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- long initialDelay = getInitialDelay();
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- System.out.println("⏳ GC 第一次运行时间：" + LocalDateTime.now().plusSeconds(initialDelay));
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-
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- scheduler.scheduleAtFixedRate(() -> {
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- LocalTime now = LocalTime.now();
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-
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- // 仅在凌晨 2:00 - 5:00 之间执行 GC
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- if (now.isBefore(LocalTime.of(16, 45)) || now.isAfter(LocalTime.of(20, 0))) {
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- System.out.println("⏸️ 当前时间不在 02:00 - 05:00 之间，跳过 GC");
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- return;
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- }
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-
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- System.out.println("🔄 GC 任务执行时间：" + LocalDateTime.now());
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- printMemoryUsage("GC 前内存状态");
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-
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- // 1. 创建老年代对象（通过长期存活对象）
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- System.out.println("创建老年代对象...");
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- List<byte[]> oldGenObjects = new java.util.ArrayList<>();
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- for (int i = 0; i < 6; i++) {
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- byte[] data = new byte[500 * 1024 * 1024]; // 分配 500MB 对象
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- oldGenObjects.add(data);
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- System.gc(); // 触发 Minor GC，让对象进入老年代
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- try {
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- Thread.sleep(100);
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- } catch (InterruptedException e) {
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- System.out.println("创建老年代对象存在错误");
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- throw new RuntimeException(e);
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- }
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- }
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- System.out.println("执行完了创建老年代对象");
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- oldGenObjects.clear(); // 清除引用
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- oldGenObjects = null; // 释放列表引用
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-
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-
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- // 2. 手动触发 Full GC
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- triggerFullGcAndShrink();
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-
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- // 3. 打印内存使用情况
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- printMemoryUsage("Full GC 后");
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-
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- // 优化 GC 触发逻辑
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- for (int i = 1; i <= 3; i++) { // 减少循环次数（原 8 次过多）
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- System.gc();
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- System.runFinalization();
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-
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- // 分配并立即释放大内存块，尝试触发堆内存收缩
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- try {
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- byte[] memoryHog = new byte[500 * 1024 * 1024]; // 分配 100MB
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- memoryHog = null; // 释放引用
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- } catch (OutOfMemoryError e) {
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- System.out.println("⚠️ 内存不足，跳过分配测试块");
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- }
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-
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- System.out.println("🚀 GC 执行第 " + i + " 次");
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- printMemoryUsage("本次 GC 后内存状态");
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-
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- try {
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- Thread.sleep(3000); // 延长间隔（原 1 秒过短）
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- } catch (InterruptedException e) {
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- e.printStackTrace();
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- }
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- }
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- }, initialDelay, 3 * 60, TimeUnit.SECONDS); // 每 10 分钟运行一次
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- }
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-
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- /**
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- * 强制触发 Full GC 并尝试释放内存给操作系统
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- */
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- private static void triggerFullGcAndShrink() {
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- System.out.println("触发 Full GC...");
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- System.gc(); // 建议 JVM 执行 GC（不保证立即执行）
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- System.runFinalization();
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-
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- // 分配并释放大内存块，促使 JVM 释放内存
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- try {
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- byte[] memoryHog = new byte[1024 * 1024 * 500]; // 分配 500MB
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- memoryHog = null;
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- } catch (OutOfMemoryError e) {
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- System.out.println("内存不足，跳过分配测试块");
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- }
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-
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- System.gc(); // 再次触发 GC
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- }
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-
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- @Override
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- public void contextDestroyed(ServletContextEvent sce) {
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- if (scheduler != null) {
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- System.out.println("🛑 GC 任务已关闭");
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- scheduler.shutdown();
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- }
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- }
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-
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- /**
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- * 计算当前时间到最近的 01:50 的秒数
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- */
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- private long getInitialDelay() {
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- LocalTime now = LocalTime.now();
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- LocalTime nextRunTime = LocalTime.of(1, 50);
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-
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- if (now.isBefore(nextRunTime)) {
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- return ChronoUnit.SECONDS.between(now, nextRunTime);
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- } else {
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- // 如果已经过了 02:00，则计算到次日 02:00 的时间
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- return ChronoUnit.SECONDS.between(now, nextRunTime.plusHours(24));
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- }
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- }
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-
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- /**
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- * 打印老年代内存使用情况
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- */
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- private void printMemoryUsage(String phase) {
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- for (MemoryPoolMXBean pool : ManagementFactory.getMemoryPoolMXBeans()) {
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- if (pool.getName().toLowerCase().contains("old") || pool.getName().toLowerCase().contains("tenured")) {
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- MemoryUsage usage = pool.getUsage();
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- System.out.printf("%s - %s: Used=%dMB, Committed=%dMB, Max=%dMB%n",
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- phase, pool.getName(), usage.getUsed() / 1024 / 1024,
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- usage.getCommitted() / 1024 / 1024, usage.getMax() / 1024 / 1024);
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- }
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- }
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- }
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-}
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-
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-
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