背景

作为面向大数据场景的半结构化、结构化存储系统，Lindorm已经在阿里发展了近十年，并始终保持着快速的能力更新和技术升级，是目前支撑阿里经济体业务的核心数据库产品之一。其在功能、性能、稳定性等方面的诸多创新历经了长时间的大规模实践考验，被全面应用于阿里集团、蚂蚁集团、菜鸟、大文娱等各个业务板块，成为目前为止公司内部数据体量最大、覆盖业务最广的数据库产品。

Lindorm Serverless 支持按需计费，弹性扩展，最大限度的降低了用户使用门槛，运维难度和容量规划操作。Lindorm CQL完全兼容了cassandra社区的Query Language，提供了类SQL的查询能力，可以非常快速的结合spring等框架，帮助业务逻辑快速开发。本文以一个简单的用户管理系统为例子，介绍如何给予Lindorm快速构建一个web服务，这个系列后续也会介绍更多复杂的使用方式。

前期准备工作

公有云用户
在阿里云首页搜索Lindorm，进入Lindorm管理控制台购买Lindorm Serverless集群，可以根据需求选择包年包月或者按量付费。

已经有集群版实例子的同学可以跳过这个步骤。

购买成功之后，实例列表就包含了一个LindormServerless类型的实例在实例管理页面找到连接信息页面，开通公网访问，获取集群链接串。

链接信息中默认都存在"CQL连接"，默认的链接地址是包括了VPC环境下的地址和端口，也可以执行公网开放功能获取公网地址和端口。Lindorm使用CQL访问都是走认证的，默认用户名和默认密码在用户控制台可以看到，通过该地方获取的用户名和密码可以访问走CQL访问Lindorm。

至此Lindorm的集群的购买工作就已经完成了。

了解Cqlsh
执行建表和KeySpace操作用户可以通过cqlsh访问lindorm serverless，操作方式请参考cqlsh使用指南。

下载到CQLSH的代码后，可以通过如下命令访问Shell

./cqlsh $host $port -u $username -p $password

其中host指的是CQL链接串中:9042之前的部分，port不填写默认为9042

创建namespace和table

cqlsh> CREATE KEYSPACE test_keyspace WITH replication = {'class': 'SimpleStrategy', 'replication_factor': '1'}  AND durable_writes = true;
cqlsh> use test_keyspace;
cqlsh:test_keyspace> CREATE TABLE user (id BIGINT , username text,  age int, password text, PRIMARY KEY (id)) ;

对应的CQL表结构
CREATE TABLE test_keyspace.user (
id bigint PRIMARY KEY,
username text,
age int,
password text);

生成SpringBoot项目

在开始实际编码之前，建议先阅读下官方文档，了解Spring Data for Cassandra项目

在Spring模版生成器中生成项目模版，所需配置如下图：

生成出来的项目下载后导入进Idea，大概如下

现在我们就拥有了一个完整spring on cql，接下来的工作就是完善代码构造一个用户管理页面啦。

构造用户管理页面

定义域模型（实体类）
本文主要针对单个用户主键场景，所有的读写操作都是针对主键ID来执行，注意主键需要标注PrimaryKey。用户ID作为主键是全局唯一的，重复写入一个用户ID会发生覆盖。

/*
 * Copyright Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.lindorm.cqldemo.entity;
import org.springframework.data.cassandra.core.mapping.CassandraType;
import org.springframework.data.cassandra.core.mapping.PrimaryKey;
import org.springframework.data.cassandra.core.mapping.Table;
@Table(value = "user")
public class UserTable {
    @PrimaryKey
    @CassandraType(type = CassandraType.Name.BIGINT)
    private long id;
    private String username;
    private String password;
    private int age;
    public long getId() {
        return id;
    }
    public UserTable setId(long id) {
        this.id = id;
        return this;
    }
    public String getUserName() {
        return username;
    }
    public UserTable setUserName(String username) {
        this.username = username;
        return this;
    }
    public String getPassword() {
        return password;
    }
    public UserTable setPassword(String password) {
        this.password = password;
        return this;
    }
    public int getAge() {
        return age;
    }
    public UserTable setAge(int age) {
        this.age = age;
        return this;
    }
}

定义spring-data接口
这里主要继承了CrudRepository，包括了比较常见的增删改查

 * Copyright Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.lindorm.cqldemo.entity;
package com.alibaba.lindorm.cqldemo.repository;
import com.alibaba.lindorm.cqldemo.entity.UserTable;import org.springframework.data.repository.CrudRepository;
public interface UserRepository extends CrudRepository<UserTable, Long> {
    UserTable findById(long id);
    void deleteById(Long id);
}

CrudRepository的接口定义如下

public interface CrudRepository<T, ID> extends Repository<T, ID> {
  <S extends T> S save(S var1);
  <S extends T> Iterable<S> saveAll(Iterable<S> var1);
  Optional<T> findById(ID var1);
  boolean existsById(ID var1);
  Iterable<T> findAll();
  Iterable<T> findAllById(Iterable<ID> var1);
  long count();
  void deleteById(ID var1);
  void delete(T var1);
  void deleteAll(Iterable<? extends T> var1);
  void deleteAll();
}

定义service
咱们这个简单的demo代码支持拿到用户列表，写入用户信息，更新用户信息，删除用户等基本功能，其支持的基本功能如图。

/*
 * Copyright Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.lindorm.cqldemo.service;
import com.alibaba.lindorm.cqldemo.entity.UserTable;
import java.util.List;
public interface UserService {
    public List<UserTable> getUserList();
    public UserTable findUserById(long id);
    public void save(UserTable userTable);
    public void edit(UserTable userTable);
    public void delete(long id);
}
/*
 * Copyright Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.lindorm.cqldemo.service;
import com.alibaba.lindorm.cqldemo.entity.UserTable;
import com.alibaba.lindorm.cqldemo.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.ArrayList;
import java.util.List;
@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserRepository userRepository;
    @Override
    public List<UserTable> getUserList() {
        List<UserTable> userList = new ArrayList<>();
        for (UserTable table : userRepository.findAll()) {
            userList.add(table);
        }
        return userList;
    }
    @Override
    public UserTable findUserById(long id) {
        return userRepository.findById(id);
    }
    @Override
    public void save(UserTable userTable) {
        userRepository.save(userTable);
    }
    @Override
    public void edit(UserTable userTable) {
        userRepository.save(userTable);
    }
    @Override
    public void delete(long id) {
        userRepository.deleteById(id);
    }
}

完成webcontroller
UserController实现基本的跳转功能，将咱们的前段页面跟service关联起来。

 * Copyright Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.lindorm.cqldemo.web;
import com.alibaba.lindorm.cqldemo.entity.UserTable;
import com.alibaba.lindorm.cqldemo.service.UserService;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import javax.annotation.Resource;
import java.util.List;
@Controller
public class UserController {
    @Resource UserService userService;
    @RequestMapping("/")
    public String index() {
        return "redirect:/list";
    }
    @RequestMapping("/list")
    public String list(Model model) {
        List<UserTable> userTables = userService.getUserList();
        model.addAttribute("userTables", userTables);
        return "user/list";
    }
    @RequestMapping("/toAdd")
    public String toAdd() {
        return "user/userAdd";
    }
    @RequestMapping("/add")
    public String add(UserTable userTable) {
        userService.save(userTable);
        return "redirect:/list";
    }
    @RequestMapping("/toEdit")
    public String toEdit(Model model,Long id) {
        UserTable userTable = userService.findUserById(id);
        model.addAttribute("userTable", userTable);
        return "user/userEdit";
    }
    @RequestMapping("/edit")
    public String edit(UserTable userTable) {
        userService.edit(userTable);
        return "redirect:/list";
    }
    @RequestMapping("/delete")
    public String delete(Long id) {
        userService.delete(id);
        return "redirect:/list";
    }
}

完成前端页面
前端页面的具体代码，请参考具体的示例代码。总共实现了3个页面，list.html负责用户展示，userAdd.html负责用户添加，userEdit.html负责用户更新页面。

完成main函数

 * Copyright Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.lindorm.cql.springdemo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
@SpringBootApplication
public class CqlDemoApplication extends SpringBootServletInitializer {
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(CqlDemoApplication.class);
    }
    public static void main(String[] args) throws Exception {
        System.out.println(System.getProperty("java.class.path"));
        SpringApplication.run(CqlDemoApplication.class, args);
    }
}

增加cassandra链接参数
通过继承AbstractCassandraConfiguration来指定链接的EndPoint，用户名，密码等信息。用户名密码可以通过阿里云管控系统或者Afanty上获取。

 * Copyright Alibaba Group Holding Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.lindorm.cqldemo.config;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.cassandra.config.AbstractCassandraConfiguration;
import org.springframework.data.cassandra.config.CqlSessionFactoryBean;
import org.springframework.data.cassandra.repository.config.EnableCassandraRepositories;
@Configuration
@EnableCassandraRepositories
public class CassandraConfig extends AbstractCassandraConfiguration {
  private String hostList = "ld-bp1r9jd815x6y8w4d-proxy-lindorm-pub.lindorm.rds.aliyuncs.com";
  private String keyspaceName = "test_keyspace";
    //需要填写自己集群的对应账号
  private String userName = "xxx";
    //需要填写自己集群的对应密码
  private String password = "xxx";
  @Override
  protected String getLocalDataCenter() {
    return "datacenter1";
  }
  protected String getContactPoints() {
    return hostList;
  }
  public String getKeyspaceName() {
    return keyspaceName;
  }
  @Override
  public CqlSessionFactoryBean cassandraSession() {
    CqlSessionFactoryBean cqlSessionFactoryBean = super.cassandraSession();
    cqlSessionFactoryBean.setPassword(password);
    cqlSessionFactoryBean.setUsername(userName);
    return cqlSessionFactoryBean;
  }
}

当然，你也可以通过更改application.properties调整cassandra参数，需要注意contact-points, username,password这几个参数是必须填写的，详细的参数请参考spring-cassandra的官方文档。