Idea创建Maven多模块+Spring-boot cassandra-CassandraTemplate的使用

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1、创建多模块的项目请参考https://blog.csdn.net/sunxiaoju/article/details/84343002

2、创建一个cassandra模块，并创建好相应的目录包以及对应的文件，如下图所示：

3、然后配置pom.xml，需要添加对应的依赖包，如下代码所示：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>Spring-root</artifactId>
        <groupId>Spring-root</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
 
    <artifactId>cassandra</artifactId>
    <dependencies>
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-cassandra</artifactId>
            <version>2.1.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.datastax.cassandra</groupId>
            <artifactId>cassandra-driver-core</artifactId>
            <version>3.6.0</version>
        </dependency>
    </dependencies>
</project>

4、然后打开cassandra数据库创建user表，cql语句为：

create table user (id bigint primary key,username text,age int);

如下图所示：

5、向user表中插入数据，cql语句为：

insert into user (id,username,age) values (1,'zs',23);
insert into user (id,username,age) values (2,'ls',24);
insert into user (id,username,age) values (3,'ww',25);

如下图所示：

6、根据数据库表创建User.java实体类，如下代码：
 

package com.win.cas.bean;

import org.springframework.data.cassandra.core.mapping.PrimaryKey;
import org.springframework.data.cassandra.core.mapping.Table;

@Table(value = "user")
public class User {
    @PrimaryKey("id")
    private int id;
    private String username;
    private int age;
    public User() {
    }
    public User(String username, int age) {
        this.username = username;
        this.age = age;
    }
    public void setUsername(String username){
        this.username=username;
    }
    public void setAge(int age){
        this.age=age;
    }
    public int getId(){
        return this.id;
    }
    public void setId(int id){
        this.id=id;
    }
    public String getUsername(){
        return this.username;
    }
    public int getAge(){
        return this.age;
    }
}

7、创建返回json对象类：JsonResult.java，如下代码：

package com.win.cas.bean;

public class JsonResult {
    private String status = null;
    private Object result = null;
    public JsonResult status(String status) {
        this.status = status;
        return this;
    }
    public void setResult(Object user){
        this.result=user;
    }
    public Object getResult(){
        return this.result;
    }
    public void setStatus(String status){
        this.status=status;
    }
    public String getStatus(){
        return this.status;
    }
}

8、创建dao接口类：UserDao.java,如下代码所示：

package com.win.cas.dao;

import com.win.cas.bean.User;
import java.util.List;
public interface UserDao {
    public User getUserById(Integer id);
    public User getUserById1(Integer id);
    public List<User> getUserList();
    public List<User> getUserList1();
    public boolean add(User user);
    public boolean update(Integer id, User user);
    public boolean delete(Integer id);
}

9、实现dao接口类：UserDaoImpl.java，如下代码所示：

package com.win.cas.dao.impl;

import com.win.cas.bean.User;
import com.win.cas.dao.UserDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.cassandra.core.CassandraTemplate;
import org.springframework.data.cassandra.core.query.Query;
import org.springframework.data.cassandra.core.query.Update;
import org.springframework.stereotype.Repository;

import java.util.List;

import static org.springframework.data.cassandra.core.query.Criteria.where;

@Repository
public class UserDaoImpl implements UserDao {
    @Autowired
    private CassandraTemplate cassandraTemplate;
    @Override
    public User getUserById(Integer id){
        String cql=String.format("select * from user where id = %d",id.intValue());
        List<User> list = cassandraTemplate.select(cql,User.class);
        if(list!=null && list.size()>0){
            return list.get(0);
        }else{
            return null;
        }
    }
    @Override
    public User getUserById1(Integer id){
        User usero = cassandraTemplate.selectOne(Query.query(where("id").is(id)),User.class );
        if(usero!=null){
            return usero;
        }
        return null;
    }
    @Override
    public List<User> getUserList(){
        String cql=String.format("select * from user");
        List<User> list = cassandraTemplate.select(cql,User.class);
        if(list!=null && list.size()>0){
            return list;
        }else{
            return null;
        }
    }
    @Override
    public List<User> getUserList1(){
        return null;
    }
    @Override
    public boolean add(User user){
        String cql=String.format("insert into user (id,username,age) values (%d,'%s',%d)",user.getId(),user.getUsername(),user.getAge());
        return cassandraTemplate.getCqlOperations().execute(cql);
    }
    @Override
    public boolean update(Integer id, User user){
        return cassandraTemplate.update(Query.query(where("id").is(id.intValue())),Update.empty().set("username",user.getUsername()).set("age",user.getAge()), User.class);
    }
    @Override
    public boolean delete(Integer id){
        return cassandraTemplate.delete(Query.query(where("id").is(id.intValue())),User.class);
    }
}

10、service接口类：UserService.java，如下代码所示：

package com.win.cas.service;

import com.win.cas.bean.User;
import java.util.List;
public interface UserService {
    public User getUserById(Integer id);
    public List<User> getUserList();
    public User getUserById1(Integer id);
    public List<User> getUserList1();
    public boolean add(User user);
    public boolean update(Integer id, User user);
    public boolean delete(Integer id);
}

11、实现service接口类：UserServiceImpl.java，如下代码所示：

package com.win.cas.service.impl;

import com.win.cas.bean.User;
import com.win.cas.dao.UserDao;
import com.win.cas.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserDao userDao;
    @Override
    public User getUserById(Integer id){
        return userDao.getUserById(id);
    }
    @Override
    public User getUserById1(Integer id){
        return userDao.getUserById1(id);
    }
    @Override
    public List<User> getUserList(){
        return userDao.getUserList();
    }
    @Override
    public List<User> getUserList1(){
        return userDao.getUserList1();
    }
    @Override
    public boolean add(User user){
        return userDao.add(user);
    }
    @Override
    public boolean update(Integer id, User user){
        return userDao.update(id, user);
    }
    @Override
    public boolean delete(Integer id){
        return userDao.delete(id);
    }
}

12、控制层代码UserController.java类，如下代码：

package com.win.cas.web;

import com.win.cas.bean.JsonResult;
import com.win.cas.bean.User;
import com.win.cas.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
public class UserController {
    @Autowired
    private UserService userService;

    /**
     * 根据ID查询用户
     * @param id
     * @return
     */
    @RequestMapping(value = "user/{id}", method = RequestMethod.GET)
    public ResponseEntity<JsonResult> getUserById (@PathVariable(value = "id") Integer id){
        JsonResult r = new JsonResult();
        try {
            User user = userService.getUserById(id);
            r.setResult(user);
            r.setStatus("ok");
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");
            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }
    /**
     * 根据ID查询用户
     * @param id
     * @return
     */
    @RequestMapping(value = "user1/{id}", method = RequestMethod.GET)
    public ResponseEntity<JsonResult> getUserById1 (@PathVariable(value = "id") Integer id){
        JsonResult r = new JsonResult();
        try {
            User user = userService.getUserById1(id);
            r.setResult(user);
            r.setStatus("ok");
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");
            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }

    /**
     * 查询用户列表
     * @return
     */
    @RequestMapping(value = "users", method = RequestMethod.GET)
    public ResponseEntity<JsonResult> getUserList (){
        JsonResult r = new JsonResult();
        try {
            List<User> users = userService.getUserList();
            r.setResult(users);
            r.setStatus("ok");
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");
            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }
    /**
     * 查询用户列表
     * @return
     */
    @RequestMapping(value = "users1", method = RequestMethod.GET)
    public ResponseEntity<JsonResult> getUserList1 (){
        JsonResult r = new JsonResult();
        try {
            List<User> users = userService.getUserList1();
            r.setResult(users);
            r.setStatus("ok");
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");
            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }
    /**
     * 添加用户
     * @param user
     * @return
     */
    @RequestMapping(value = "user", method = RequestMethod.POST)
    public ResponseEntity<JsonResult> add (@RequestBody User user){
        JsonResult r = new JsonResult();
        try {
            boolean orderId = userService.add(user);
            if (!orderId) {
                r.setResult(orderId);
                r.setStatus("fail");
            } else {
                r.setResult(orderId);
                r.setStatus("ok");
            }
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");

            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }

    /**
     * 根据id删除用户
     * @param id
     * @return
     */
    @RequestMapping(value = "user/{id}", method = RequestMethod.DELETE)
    public ResponseEntity<JsonResult> delete (@PathVariable(value = "id") Integer id){
        JsonResult r = new JsonResult();
        try {
            boolean orderId = userService.delete(id);
            if (!orderId) {
                r.setResult(orderId);
                r.setStatus("fail");
            } else {
                r.setResult(orderId);
                r.setStatus("ok");
            }
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");

            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }

    /**
     * 根据id修改用户信息
     * @param user
     * @return
     */
    @RequestMapping(value = "user/{id}", method = RequestMethod.PUT)
    public ResponseEntity<JsonResult> update (@PathVariable("id") Integer id, @RequestBody User user){
        JsonResult r = new JsonResult();
        try {
            boolean ret = userService.update(id, user);
            if (!ret) {
                r.setResult(ret);
                r.setStatus("fail");
            } else {
                r.setResult(ret);
                r.setStatus("ok");
            }
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");

            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }
}

13、启动类代码：Application.java类，如下代码：

package com.win.cas;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@EnableAutoConfiguration
@SpringBootApplication
public class Application {
    public static void main( String[] args )
    {
        System.out.println( "start....." );
        SpringApplication.run(Application.class, args);
    }
}

14、application.yml配置文件：

spring:
  data:
    cassandra:
      keyspace-name: mycasdb
      contact-points: 127.0.0.1
      port: 9042
      username: cassandra
      password: cassandra

15、通过Debug启动程序，然后在浏览器中输入：http://127.0.0.1:8080/user/1或http://127.0.0.1:8080/user1/2，即可查询cassandra数据表中的内容，此两个地址所实现的代码是略有不同的，如下图所示：

16、输入：http://127.0.0.1:8080/users，即可查询user表中的所有记录，如下图所示：

17、添加用户，打开火狐浏览器的RESTClient调试工具，然后添加http头，如下图所示：

18、请求方法选择Post，然后输入：，在正文中输入：{"id":4,"username":"zl","age":26}，如下图所示：

19、点击发送请求之后可通过http://127.0.0.1:8080/users进行查看，如下图所示：

20、修改用户信息，选择put请求，然后输入：http://127.0.0.1:8080/user/4，输入要修改的内容：{"id":4,"username":"hahazl23423","age":80}，表示修改指定ID的信息，点击发送即可修改，并且有返回状态，如下图所示：

21、再次刷新获取用户列表，如下图所示：

22、删除用户信息，选择DELETE请求，然后输入：http://127.0.0.1:8080/user/2，不需要输入内容，点击发送即可删除，并且有返回状态，如下图所示：

23、重新刷新即可删除，如下图所示：