使用 Simple-Spring-Memcached: AssignCache

接上一篇的 MultiCache ，这篇主要讲一下 AssignCache 的使用。继续解决上一个场景中没有解决的问题。

根据某几个 role ID 查询所有的 User。查询关联两个以上的 Model，在更新其中一个时，需要让相关的缓存失效

Method:

@Override
@ReadThroughAssignCache(assignedKey = "user/getUsersByRoleIds", namespace = "user", expiration = 60)
public List<User> getUsersByRoleIds(@ParameterValueKeyProvider final List<Long> ids) {
    return (List<User>) sqlMapClientTemplate.queryForList("getUsersByRoleIds", ids);
}

SQL:

<select id="getUsersByRoleIds" parameterClass="list" resultClass="user">
    SELECT u.id, u.name, r.id as "role.id", r.name as "role.name"
    FROM user u, user_role ur, role r
    WHERE u.id = ur.userid and r.id = ur.roleid and ur.roleid in
    (<iterate conjunction=",">
        #ids[]#
    </iterate>) order by r.id
</select>

Unit Test:

@Test
public void testGetUsersByRoleIds() throws Exception {
    List<Long> list = Arrays.asList(1L, 2L);

    List users = userDao.getUsersByRoleIds(list);

    log.info("users: " + users);

    assertNotNull(users);
    assertEquals(3, users.size());
}    

Log4j log:

set user:user/getUsersByRoleIds 8 60 378

{"v":{"java.util.ArrayList":[{"me.batizhao.model.User":{"id":1000,"name":"Tom","role":{"me.batizhao.model.Role":{"id":1,"name":"ROLE_ADMIN"}}}},{"me.batizhao.model.User":{"id":1002,"name":"Jack","role":{"me.batizhao.model.Role":{"id":1,"name":"ROLE_ADMIN"}}}},{"me.batizhao.model.User":{"id":1001,"name":"Jerry","role":{"me.batizhao.model.Role":{"id":2,"name":"ROLE_USER"}}}}]}}

这个场景不太适合做 @UpdateAssignCache，这里使用 Simple-Spring-Memcached: SingleCache 中的 UserCache 类，增加一个方法

@InvalidateAssignCache(assignedKey = "user/getUsersByRoleIds", namespace = "user")
public void invalidategetUsersByRoleIds(){
}

然后在 RoleManagerImpl.updateRole() 中增加一句

userCache.invalidategetUsersByRoleIds();

先执行 DAO Unit Test:

@Test
public void testGetUsersByRoleIds() throws Exception {
    List<Long> list = Arrays.asList(1L, 2L);

    List users = userDao.getUsersByRoleIds(list);

    log.info("users: " + users);

    assertNotNull(users);
    assertEquals(3, users.size());
}

Memcached Log:

<21 get user:user/getUsersByRoleIds
>21 END
<21 set user:user/getUsersByRoleIds 8 60 378
>21 STORED	

再执行 Service Unit Test:

@Test
public void testUpdateRole() throws Exception {
    Role role = new Role();
    role.setId(1L);
    role.setName("ROLE_ADMIN");

    roleManager.updateRole(role);

    role = roleManager.getRole(1L);

    log.info("Role: " + role);

    assertEquals("ROLE_ADMIN", role.getName());

}
        	

Memcached Log:

<21 delete user:user/getUsersByRoleIds
>21 DELETED	        

以上章节的所有代码在 Github.