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

 1 /**
 2  * @author：YZH
 3  * time: 2019/8/8 12:16
 4  * description: 建立抽象类，定义相关方法
 5  **/
 6 public abstract class BaseAdapt<T,Base>{
 7     private Base base;
 8 
 9     public  BaseAdapt(Base base){
10         this.base = base;
11     }
12 
13     /**
14      * 查询list数据（默认要实现）
15      * @return
16      */
17     public abstract List<T>list();
18 
19     /**
20      * 查询数量
21      * @return
22      */
23     public  int count(){return 0;}
24 
25     /**
26      * 返回单个对象V
27      * @return
28      */
29     public T getT(){
30         return null;
31     }
32 
33 }

View Code

3、建立异步调用方法

 1 @Component
 2 public  class DemoThread {
 3 
 4 
 5     @Async
 6     public <T,Base> Future<T> getT(BaseAdapt<T,Base>baseAdapt) {
 7         return new AsyncResult<>(baseAdapt.getT());
 8     }
 9 
10     @Async
11     public <T,Base> Future<List<T>> list(BaseAdapt<T,Base> baseAdapt){
12         return new AsyncResult<>(baseAdapt.list());
13     }
14 
15     @Async
16     public Future<Integer>count(BaseAdapt baseAdapt){
17         return new AsyncResult<>(baseAdapt.count());
18     }
19 }

View Code

4、建立一个dao类，模拟访问数据库

 1 @Component
 2 public class UserDao {
 3 
 4     public User getUser(){
 5         User user = new User();
 6         user.setName("测试");
 7         user.setId(UUID.randomUUID().toString());
 8         return user;
 9     }
10 
11     public List<User>listUser(){
12         int num = new Random(1).nextInt(10);
13         System.out.println("随机生成："+num+"个user");
14         List<User>users = new ArrayList<>(num);
15         for (int i = 0; i < num; i++) {
16             User user = new User();
17             user.setId(UUID.randomUUID().toString());
18             user.setName("测试"+i);
19             users.add(user);
20         }
21         return users;
22     }
23     public int count(){
24         return new Random(1).nextInt(10);
25     }
26 }

View Code

5、调用

a、只实现默认方法，获取list数据

 1     @Test
 2     public void  testAsync() throws InstantiationException, IllegalAccessException, ExecutionException, InterruptedException {
 3         BaseAdapt<User,UserDao>baseAdapt = new BaseAdapt<User, UserDao>(userDao) {
 4             @Override
 5             public List<User> list() {
 6                 return userDao.listUser();
 7             }
 8         };
 9         Future<List<User>> list = demoThread.list(baseAdapt);
10         Future<Integer> count = demoThread.count(baseAdapt);
11         List<User> users = list.get();
12         Integer integer = count.get();
13         System.out.println("总数："+integer);
14         for (User user : users) {
15             System.out.println(user);
16         }
17     }

View Code

b、新增查询数量

 1 @Test
 2     public void  testAsync() throws InstantiationException, IllegalAccessException, ExecutionException, InterruptedException {
 3         BaseAdapt<User,UserDao>baseAdapt = new BaseAdapt<User, UserDao>(userDao) {
 4             @Override
 5             public List<User> list() {
 6                 return userDao.listUser();
 7             }
 8             @Override
 9             public int count() {
10                 return userDao.count();
11             }
12         };
13         Future<List<User>> list = demoThread.list(baseAdapt);
14         Future<Integer> count = demoThread.count(baseAdapt);
15         List<User> users = list.get();
16         Integer integer = count.get();
17         System.out.println("总数："+integer);
18         for (User user : users) {
19             System.out.println(user);
20         }
21     }

View Code