springboot使用异步查询数据

主要适用于需要查询多种类型的数据，而且二者的参数没有关联的情况。

1、开启异步调用注解

2、创建抽象类，定义相关方法

/**
 * @author：YZH
 * time: 2019/8/8 12:16
 * description: 建立抽象类，定义相关方法
 **/
public abstract class BaseAdapt<T,Base>{
    private Base base;

    public  BaseAdapt(Base base){
        this.base = base;
    }

    /**
     * 查询list数据（默认要实现）
     * @return
     */
    public abstract List<T>list();

    /**
     * 查询数量
     * @return
     */
    public  int count(){return 0;}

    /**
     * 返回单个对象V
     * @return
     */
    public T getT(){
        return null;
    }

}

3、建立异步调用方法

@Component
public  class DemoThread {


    @Async
    public <T,Base> Future<T> getT(BaseAdapt<T,Base>baseAdapt) {
        return new AsyncResult<>(baseAdapt.getT());
    }

    @Async
    public <T,Base> Future<List<T>> list(BaseAdapt<T,Base> baseAdapt){
        return new AsyncResult<>(baseAdapt.list());
    }

    @Async
    public Future<Integer>count(BaseAdapt baseAdapt){
        return new AsyncResult<>(baseAdapt.count());
    }
}

4、建立一个dao类，模拟访问数据库

@Component
public class UserDao {

    public User getUser(){
        User user = new User();
        user.setName("测试");
        user.setId(UUID.randomUUID().toString());
        return user;
    }

    public List<User>listUser(){
        int num = new Random(1).nextInt(10);
        System.out.println("随机生成："+num+"个user");
        List<User>users = new ArrayList<>(num);
        for (int i = 0; i < num; i++) {
            User user = new User();
            user.setId(UUID.randomUUID().toString());
            user.setName("测试"+i);
            users.add(user);
        }
        return users;
    }
    public int count(){
        return new Random(1).nextInt(10);
    }
}

5、调用

a、只实现默认方法，获取list数据

    @Test
    public void  testAsync() throws InstantiationException, IllegalAccessException, ExecutionException, InterruptedException {
        BaseAdapt<User,UserDao>baseAdapt = new BaseAdapt<User, UserDao>(userDao) {
            @Override
            public List<User> list() {
                return userDao.listUser();
            }
        };
        Future<List<User>> list = demoThread.list(baseAdapt);
        Future<Integer> count = demoThread.count(baseAdapt);
        List<User> users = list.get();
        Integer integer = count.get();
        System.out.println("总数："+integer);
        for (User user : users) {
            System.out.println(user);
        }
    }

b、新增查询数量

@Test
    public void  testAsync() throws InstantiationException, IllegalAccessException, ExecutionException, InterruptedException {
        BaseAdapt<User,UserDao>baseAdapt = new BaseAdapt<User, UserDao>(userDao) {
            @Override
            public List<User> list() {
                return userDao.listUser();
            }
            @Override
            public int count() {
                return userDao.count();
            }
        };
        Future<List<User>> list = demoThread.list(baseAdapt);
        Future<Integer> count = demoThread.count(baseAdapt);
        List<User> users = list.get();
        Integer integer = count.get();
        System.out.println("总数："+integer);
        for (User user : users) {
            System.out.println(user);
        }
    }