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);
         }
     }