智能包名选择策略：如何高效实现优先级随机选择

private static final List<String> HIGH_PRIORITY_PAG = Collections.unmodifiableList(
    Arrays.asList(
        "com.smile.gifmaker",
        "com.kuaishou.nebula",
        "com.baidu.searchbox",
        "com.baidu.searchbox.lite",
        "com.baidu.wenku"
    )
);

private static final List<String> HIGH_PRIORITY_PAG = List.of(
    "com.smile.gifmaker",
    "com.kuaishou.nebula",
    "com.baidu.searchbox",
    "com.baidu.searchbox.lite",
    "com.baidu.wenku"
);

private static List<String> appList = new ArrayList<>();

import java.util.*;
import java.util.stream.Collectors;

public class PackageSelector {
    private static List<String> appList = new ArrayList<>();
    private static final List<String> HIGH_PRIORITY_PAG = List.of(
        "com.smile.gifmaker",
        "com.kuaishou.nebula",
        "com.baidu.searchbox",
        "com.baidu.searchbox.lite",
        "com.baidu.wenku"
    );
    
    private static final Random random = new Random();

    /
     * 获取一个随机包名
     * @return 随机选择的包名，如果所有列表都为空则返回null
     */
    public static String getRandomPackage() {
        // 如果appList为空，从HIGH_PRIORITY_PAG随机选择
        if (appList.isEmpty()) {
            return getRandomElement(HIGH_PRIORITY_PAG);
        }
        
        // 获取appList和HIGH_PRIORITY_PAG的交集
        List<String> intersection = appList.stream()
                .filter(HIGH_PRIORITY_PAG::contains)
                .collect(Collectors.toList());
        
        // 如果有交集，从交集中随机选择
        if (!intersection.isEmpty()) {
            return getRandomElement(intersection);
        }
        
        // 否则从appList中随机选择
        return getRandomElement(appList);
    }

    /
     * 从列表中随机选择一个元素
     * @param list 源列表
     * @return 随机选择的元素，如果列表为空则返回null
     */
    private static String getRandomElement(List<String> list) {
        if (list == null || list.isEmpty()) {
            return null;
        }
        return list.get(random.nextInt(list.size()));
    }
}

public static void main(String[] args) {
    // 测试1: appList为空，从HIGH_PRIORITY_PAG随机选择
    appList = new ArrayList<>();
    System.out.println("Test 1: " + getRandomPackage());  // 输出 HIGH_PRIORITY_PAG 中的随机包名

    // 测试2: appList包含HIGH_PRIORITY_PAG中的元素
    appList = Arrays.asList("com.baidu.searchbox", "com.example.test", "com.other.app");
    System.out.println("Test 2: " + getRandomPackage());  // 可能返回 "com.baidu.searchbox"

    // 测试3: appList不包含HIGH_PRIORITY_PAG中的元素
    appList = Arrays.asList("com.example.test1", "com.example.test2");
    System.out.println("Test 3: " + getRandomPackage());  // 返回 "com.example.test1" 或 "com.example.test2"

    // 测试4: appList和HIGH_PRIORITY_PAG都为空
    appList = new ArrayList<>();
    HIGH_PRIORITY_PAG = List.of();  // 假设HIGH_PRIORITY_PAG为空
    System.out.println("Test 4: " + getRandomPackage());  // 返回 null
}

private static final List<String> appList = new CopyOnWriteArrayList<>();

private static String getRandomElement(List<String> list) {
    if (list == null || list.isEmpty()) {
        return null;
    }
    return list.get(ThreadLocalRandom.current().nextInt(list.size()));
}

public static String getWeightedRandomPackage(Map<String, Integer> packageWeights) {
    List<String> weightedList = new ArrayList<>();
    for (Map.Entry<String, Integer> entry : packageWeights.entrySet()) {
        for (int i = 0; i < entry.getValue(); i++) {
            weightedList.add(entry.getKey());
        }
    }
    return getRandomElement(weightedList);
}