员工上网监控软件的Java跳表算法及日志检索优化

import java.util.ArrayList;
import java.util.List;
import java.util.Random;
/**
 * 员工上网监控软件日志存储跳表实现
 * 关键字：日志时间戳（Long类型），存储日志完整信息
 */
public class LogSkipList {
    // 跳表节点类，存储日志数据
    static class LogNode {
        // 关键字：日志时间戳
        private long timestamp;
        // 日志数据：终端IP
        private String terminalIp;
        // 日志数据：访问URL
        private String visitUrl;
        // 日志数据：访问时长（秒）
        private int visitDuration;
        // 各层链表的后继节点
        private LogNode[] forward;
        // 构造函数
        public LogNode(long timestamp, String terminalIp, String visitUrl, int visitDuration, int level) {
            this.timestamp = timestamp;
            this.terminalIp = terminalIp;
            this.visitUrl = visitUrl;
            this.visitDuration = visitDuration;
            // 初始化各层后继节点数组
            this.forward = new LogNode[level + 1];
        }
    }
    // 跳表最大层数
    private static final int MAX_LEVEL = 16;
    // 随机数生成器，用于节点晋升
    private static final Random random = new Random();
    // 跳表当前最高层数
    private int currentLevel;
    // 跳表头节点（哨兵节点）
    private LogNode head;
    // 构造函数，初始化跳表
    public LogSkipList() {
        currentLevel = 0;
        // 初始化头节点，层数为MAX_LEVEL
        head = new LogNode(0, "", "", 0, MAX_LEVEL);
    }
    /**
     * 随机生成节点的晋升层数
     * @return 节点的晋升层数
     */
    private int randomLevel() {
        int level = 0;
        // 以1/2的概率向上晋升，直到达到最大层数
        while (random.nextDouble() < 0.5 && level < MAX_LEVEL) {
            level++;
        }
        return level;
    }
    /**
     * 插入日志节点到跳表
     * @param timestamp 日志时间戳
     * @param terminalIp 终端IP
     * @param visitUrl 访问URL
     * @param visitDuration 访问时长（秒）
     */
    public void insert(long timestamp, String terminalIp, String visitUrl, int visitDuration) {
        // 用于记录各层需要更新的节点
        LogNode[] update = new LogNode[MAX_LEVEL + 1];
        LogNode current = head;
        // 从最高层开始向下检索，找到插入位置的前驱节点
        for (int i = currentLevel; i >= 0; i--) {
            while (current.forward[i] != null && current.forward[i].timestamp < timestamp) {
                current = current.forward[i];
            }
            update[i] = current;
        }
        // 生成当前节点的晋升层数
        int newLevel = randomLevel();
        // 如果新生成的层数高于当前最高层，更新update数组的高层部分
        if (newLevel > currentLevel) {
            for (int i = currentLevel + 1; i <= newLevel; i++) {
                update[i] = head;
            }
            currentLevel = newLevel;
        }
        // 创建新节点并插入到跳表中
        LogNode newNode = new LogNode(timestamp, terminalIp, visitUrl, visitDuration, newLevel);
        for (int i = 0; i <= newLevel; i++) {
            newNode.forward[i] = update[i].forward[i];
            update[i].forward[i] = newNode;
        }
    }
    /**
     * 按时间范围检索日志
     * @param startTimestamp 起始时间戳
     * @param endTimestamp 结束时间戳
     * @return 时间范围内的日志节点列表
     */
    public List<LogNode> searchByTimeRange(long startTimestamp, long endTimestamp) {
        List<LogNode> result = new ArrayList<>();
        LogNode current = head;
        // 从最高层向下检索，定位到起始时间戳的前驱节点
        for (int i = currentLevel; i >= 0; i--) {
            while (current.forward[i] != null && current.forward[i].timestamp < startTimestamp) {
                current = current.forward[i];
            }
        }
        // 从底层链表开始遍历，收集时间范围内的节点
        current = current.forward[0];
        while (current != null && current.timestamp <= endTimestamp) {
            result.add(current);
            current = current.forward[0];
        }
        return result;
    }
    // 测试方法
    public static void main(String[] args) {
        LogSkipList skipList = new LogSkipList();
        // 模拟插入5条员工上网日志
        skipList.insert(1735689600000L, "192.168.1.101", "https://www.baidu.com", 60);
        skipList.insert(1735689900000L, "192.168.1.102", "https://www.github.com", 120);
        skipList.insert(1735690200000L, "192.168.1.101", "https://www.csdn.net", 80);
        skipList.insert(1735690500000L, "192.168.1.103", "https://www.taobao.com", 150);
        skipList.insert(1735690800000L, "192.168.1.102", "https://www.stackoverflow.com", 200);
        // 检索1735689600000L到1735690500000L之间的日志
        List<LogNode> logs = skipList.searchByTimeRange(1735689600000L, 1735690500000L);
        System.out.println("时间范围内的员工上网日志：");
        for (LogNode log : logs) {
            System.out.printf("时间戳：%d, 终端IP：%s, 访问URL：%s, 访问时长：%d秒%n",
                    log.timestamp, log.terminalIp, log.visitUrl, log.visitDuration);
        }
    }
}