SpringBoot中使用数据缓存

在实际开发中，对于要反复读写的数据，最好的处理方式是将之在内存中缓存一份，频繁的数据库访问会造成程序效率低下，同时内存的读写速度本身就要强于硬盘。Spring在这一方面给我们提供了诸多的处理手段，而Spring Boot又将这些处理方式进一步简化，接下来我们就来看看如何在Spring Boot中解决数据缓存问题。

标题

使用MySQL，在pom.xml中添加数据库驱动。
pom.xml

<?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">    <modelVersion>4.0.0</modelVersion>    <groupId>com.wangh</groupId>    <artifactId>springboot_cache</artifactId>    <version>0.0.1-SNAPSHOT</version>    <packaging>jar</packaging>    <name>springboot_cache</name>    <description>Demo project for Spring Boot</description>    <parent>        <groupId>org.springframework.boot</groupId>        <artifactId>spring-boot-starter-parent</artifactId>        <version>1.5.4.RELEASE</version>        <relativePath/> <!-- lookup parent from repository -->    </parent>    <properties>        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>        <java.version>1.8</java.version>    </properties>    <dependencies>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-cache</artifactId>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-data-jpa</artifactId>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-web</artifactId>        </dependency>        <dependency>            <groupId>mysql</groupId>            <artifactId>mysql-connector-java</artifactId>            <version>5.1.40</version>        </dependency>        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-test</artifactId>            <scope>test</scope>        </dependency>    </dependencies>    <build>        <plugins>            <plugin>                <groupId>org.springframework.boot</groupId>                <artifactId>spring-boot-maven-plugin</artifactId>            </plugin>        </plugins>    </build></project>

配置application.properties

spring.datasource.driver-class-name=com.mysql.jdbc.Driverspring.datasource.url=jdbc:mysql://localhost:3306/girl?useUnicode=true&characterEncoding=utf-8spring.datasource.username=systemspring.datasource.password=mysqlspring.jpa.hibernate.ddl-auto=updatespring.jpa.show-sql=truespring.jackson.serialization.indent_output=true

创建实体类

@Entitypublic class Person {    @Id    @GeneratedValue    private Long id;    private String name;    private String address;    private Integer age;    public Person() {    }    public Long getId() {        return id;    }    public void setId(Long id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getAddress() {        return address;    }    public void setAddress(String address) {        this.address = address;    }    public Integer getAge() {        return age;    }    public void setAge(Integer age) {        this.age = age;    }    public Person(Long id, String name, String address, Integer age) {        this.id = id;        this.name = name;        this.address = address;        this.age = age;    }}

创建实体类的Repository

public interface PersonRepository extends JpaRepository<Person,Long> {}

创建业务类

业务接口

public interface PersonService {    Person save(Person person);    void remove(Long id);    Person findOne(Person person);}

实现类

@Servicepublic class PersonServiceImpl implements PersonService {    @Resource    private PersonRepository personRepository;    //@CachePut： 新增或更新数据到缓存，缓存名称为people，数据的key是person.id    @CachePut(value = "people", key = "#person.id")     @Override    public Person save(Person person) {        Person p = personRepository.save(person);        System.out.println("为id、key为" + p.getId() + "数据做了缓存");        return p;    }    //@CacheEvict:从缓存people中删除key为id的数据，如果没有指定key,方法参数作为key保存在缓存中    @CacheEvict(value = "people")    @Override    public void remove(Long id) {        System.out.println("删除了key为" + id + "数据缓存");        personRepository.delete(id);    }    //key为person的id数据缓存到people中    @Cacheable(value = "people", key = "#person.id")    @Override    public Person findOne(Person person) {        Person p = personRepository.findOne(person.getId());        System.out.println("为id、key为" + p.getId() + "数据做了缓存");        return p;    }}

关于这个实现类注意如下几点：

1.@CachePut表示缓存新添加的数据或者更新的数据到缓存中，两个参数value表示缓存的名称为people，key表示缓存的key为person的id2.@CacheEvict表示从缓存people中删除key为id的数据3.@Cacheable表示添加数据到缓存中，缓存名称为people，缓存key为person的id属性。

创建Controller

@RestControllerpublic class CacheController {    @Resource    private PersonService personService;    @RequestMapping("/put")    public Person put(Person person){        return personService.save(person);    }    @RequestMapping("/cache")    public Person cache(Person person){        return personService.findOne(person);    }    @RequestMapping("/evict")    public String evict(Long id){        personService.remove(id);        return "ok";    }}

大功告成了！