Java递归演示

父类包含子类型递归

子类

@Data
public class Rule {
    private int ruleId;
    private String name;
    private int toId;

    public Rule(int ruleId, String name, int toId) {
        this.ruleId = ruleId;
        this.name = name;
        this.toId = toId;
    }
}

父类

@Data
public class Module {
    private int id;
    private String name;
    private List<Rule> rules;

    public Module(int id, String name) {
        this.id = id;
        this.name = name;
    }
}

测试

public class Test {
    public static void main(String[] args) {

        Module module1 = new Module(1, "M1");
        Module module2 = new Module(2, "M2");
        Module module3 = new Module(3, "M3");
        Module module4 = new Module(4, "M4");
        Module module5 = new Module(5, "M5");

        Rule r1 = new Rule(11, "R1", 2);
        Rule r2 = new Rule(12, "R2", 3);
        Rule r3 = new Rule(13, "R3", 4);
        Rule r4 = new Rule(14, "R4", 5);

        module1.setRules(Arrays.asList(r1, r2));
        module2.setRules(Arrays.asList(r3, r4));

        List<Module> list = Arrays.asList(module1, module2, module3, module4, module5);
        List<Integer> ids = list.stream().map(module -> module.getId()).collect(Collectors.toList());
        Map<Integer, Module> moduleMap = list.stream().collect(Collectors.toMap(Module::getId, module -> module));

        List<Integer> result = new ArrayList<>();
        List<Integer> integers = handleTree(module2, ids, moduleMap, result);
        System.out.println(integers);

    }

    public static List<Integer> handleTree(Module target, List<Integer> moduleIdList, Map<Integer, Module> moduleMap, List<Integer> result) {
        if (target != null) {
            // 逻辑删除模块
            System.out.println("删除模块" + target.getId());
            result.add(target.getId());
            if (!CollectionUtils.isEmpty(target.getRules())) {
                for (Rule rule:target.getRules()) {
                    // 逻辑删除连线
                    System.out.println("删除连线" + rule.getRuleId());
                    if (rule.getToId() != 0 && moduleIdList.contains(rule.getToId())) {
                        Module module = moduleMap.get(rule.getToId());
                        handleTree(module, moduleIdList, moduleMap, result);
                    }
                }
            }
        }
        return result;
    }
}