springboot入门使用

一、什么是springboot，有什么用

　　springboot是一个开发框架，其出现的目的利用约定大于配置的思想来让开发者摆脱spring繁琐的配置，简化开发。其不是spring框架的替代品，是spring框架的另外一种使用形式。

二、springboot的快速使用

　　1.登录到spring官网  找到如下页面，然后选择自己想要的开发环境和版本，

       

　　2.解压压缩包并导入到eclipse，就可以启动项目了，下面是程序的入口

package com.example.demo;

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

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

三、springboot使用

　　1.配置文件properties的加载

#myconfig.properties配置文件
com.kyle.name=邓zm
com.kyle.age=27

　　

/**
 * 自定义配置文件的加载，需要加上下面的注解，并导入相关的包
 * 如果是主配置文件application.properties加载，则只需要@Value就能获取数据
 */
@Component
@ConfigurationProperties
@PropertySource("classpath:myconfig.properties")
public class UserInfo {

    @Value("${com.kyle.name}")
    private String name;
    
    @Value("${com.kyle.age}")
    private int age;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}

　　2.springboot集成mybatis（只说和spring框架的差别）

        <!-- 引入jar包 -->
        <dependency>
          <groupId>mysql</groupId>
          <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>    

#application.properties文件中引入配置文件和映射文件，
#没有配置文件也可以不引入
mybatis.config-locations=classpath:mybatis-config.xml
mybatis.mapper-locations=classpath:mapper/*.xml

　　

　　3.springboot集成redis集群

<!--引入相关jar包-->
<dependency>  
    <groupId>org.springframework.boot</groupId>  
    <artifactId>spring-boot-starter-redis</artifactId>  
</dependency>  

#redis集群配置 redis.properties
spring.redis.cluster.nodes=111.230.239.152:7000,111.230.239.152:7001,111.230.239.152:7002,111.230.239.152:8000,111.230.239.152:8001,111.230.239.152:8002
spring.redis.password=12345
spring.redis.pool.max-active=8
spring.redis.pool.max-wait=-1
spring.redis.pool.max-idle=8
spring.redis.pool.min-idle=0
spring.redis.timeout=1000
spring.redis.commandTimeout=5000

@Component
@Configuration
@PropertySource("classpath:redis.properties")
public class RedisConfig {
    
    /**
     * 设置数据存入redis 的序列化方式
     *</br>redisTemplate序列化默认使用的jdkSerializeable,存储二进制字节码,导致key会出现乱码，所以自定义
     *序列化类
     */
    @Bean
    @SuppressWarnings({ "rawtypes", "unchecked" })
    public RedisTemplate<Object,Object> redisTemplate(RedisConnectionFactory redisConnectionFactory)throws UnknownHostException {
        
        RedisTemplate<Object,Object> redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        
        Jackson2JsonRedisSerializer serializer =new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper objectMapper =new ObjectMapper();
        objectMapper.setVisibility(PropertyAccessor.ALL,JsonAutoDetect.Visibility.ANY);
        objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        serializer.setObjectMapper(objectMapper);
 
        redisTemplate.setValueSerializer(serializer);
        redisTemplate.setKeySerializer(new StringRedisSerializer());
 
        redisTemplate.afterPropertiesSet();
 
        return redisTemplate;
    }
 
}

@Service
public class UserServiceImpl implements UserService {
    
    @Autowired
    private UserMapper userMapper;
    
    @Resource
    private RedisTemplate<String,Object> redisTemplate;

    @Override
    public User getUserInfoById(Long id) {
        User user = (User)redisTemplate.opsForValue().get("user:"+id);
        if(user == null ){
            user = userMapper.getUserInfoById(id);
            redisTemplate.opsForValue().set("user:"+id, user);
        }
        return user;
    }
}

　　4.springboot开启定时任务

@MapperScan("com.example.demo.dao")
@SpringBootApplication
@EnableScheduling //开启定时任务
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

@Component
public class SchedulerTask {

    private int count=0;

    @Scheduled(cron="*/1 * * * * ?")
    private void process(){
        
        System.out.println("this is scheduler task runing  "+(count++));
    }

}

　　5.springboot的事务

@MapperScan("com.example.demo.dao")
@SpringBootApplication
@EnableScheduling
@EnableTransactionManagement //事务管理
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

@Override
    @Transactional(readOnly=false,propagation=Propagation.REQUIRED)
    public void updateUser(User user) {
        
        User user1 = new User();
        user1.setUserId(1);
        user1.setName("yao1");
        
        User user2 = new User();
        user2.setUserId(2);
        user2.setName("Xiaoxiao1");
        
        userMapper.updateUser(user1);
        int i = 1/0;
        userMapper.updateUser(user2);
    }