Spring Boot設置并使用緩存的步驟

2024-07-14 08:43:34

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幾個緩存注解的作用：

@Cacheable：將方法的返回結果根據key指定的鍵保存在緩存中，以后要獲取相同的數據直接從緩存中共獲取

cacheNames/value：指定Cache組件名稱
key：指定緩存時使用的key，默認使用方法參數值，可以使用#a0、#p0、#參數名等，支持SpEL表達式，root可省略
keyGenerator：指定key的生成器的組件id，如自定義的KeyGenerator
cacheManager：指定緩存管理器
cacheResolver：指定緩存解析器
condition：指定在哪種條件下緩存，如condition = “#id>=1”在參數>=1時緩存
unless：指定該條件為真時不緩存
sync：指定是否使用異步模式

@CachePut：不管緩存中是否有需要的數據，都會執行該注解標注的方法，并將結果更新到緩存，屬性見上

@CacheEvit：執行方法后，清除key指定的緩存

allEntries：默認為false，值為true，刪除所有緩存
beforeInvocation：默認為false，值為true，在方法調用之前清除緩存

@CacheConfig：定義一些通用或公共的規則，如cacheNames、keyGenerator等

可使用的SpEL表達式：

Spring,Boot,緩存

使用緩存的步驟：

（1）創建一個Spring Boot應用，勾選Cache、Web、MySQL、Mybatis模塊,在主程序類上添加注解，開啟基于注解的緩存

@MapperScan(basePackages = "com.youngpain.cache.mapper")@SpringBootApplication@EnableCaching

（2）創建JavaBean，和數據庫中的表對應，并配置數據源

spring: datasource:  url: jdbc:mysql://localhost:3306/mybatis_database  username: root  password: 1741248769  driver-class-name: com.mysql.jdbc.Driver redis:  host: 39.108.114.57#開啟駝峰命名法mybatis: configuration:  map-underscore-to-camel-case: truelogging: level:  com.youngpain.cache.mapper: debug

（3）創建mapper接口進行增刪改查操作

/** * 部門表的增刪改查操作 */public interface DepartmentMapper {  @Insert("insert into department(id,depart_name,depart_build) values(#{id},#{depart_name},#{depart_build})")  void insertDepartment(Department department);  @Delete("delete from department where id=#{id}")  void deleteDepartment(Integer id);  @Update("update department set depart_name=#{departName},depart_build=#{departBuild} where id=#{id}")  void updateDepartment(Department department);  @Select("select * from department where id=#{id}")  Department getDepartmentById(Integer id);}

（4）創建service

@Service@CacheConfig(cacheNames = {"departs"})public class DepartmentService {  @Autowired  DepartmentMapper departmentMapper;  @Cacheable(key = "#a0.id")  public void insertDepartment(Department department) {    departmentMapper.insertDepartment(department);  }  @CacheEvict(key = "#p0")  public void deleteDepartment(Integer id) {    departmentMapper.deleteDepartment(id);  }  @CachePut(key = "#a0.id")  public Department updateDepartment(Department department) {    departmentMapper.updateDepartment(department);    return department;  }  @Cacheable(key = "#id", condition = "#p0>=1")  public Department getDepartmentById(Integer id) {    return departmentMapper.getDepartmentById(id);  }}

（5）創建controller

@Controllerpublic class DepartmentController {  @Autowired  DepartmentService departmentService;  @GetMapping("/index")  public String index() {    return "index";  }  @GetMapping("/deleteDepart/{id}")  public String deleteDepart(@PathVariable("id") Integer id, Model model) {    model.addAttribute("condition", "delete");    Department delete = departmentService.getDepartmentById(id);    model.addAttribute("department", delete);    departmentService.deleteDepartment(id);    return "success";  }  @PostMapping("/updateDepart")  public String updateDepart(Department department, Model model) {    model.addAttribute("condition", "update");    Department update = departmentService.updateDepartment(department);    model.addAttribute("department", update);    return "success";  }  @GetMapping("/getDepart/{id}")  public String getDepartmentById(@PathVariable("id") Integer id, Model model) {    model.addAttribute("condition", "delete");    Department get = departmentService.getDepartmentById(id);    model.addAttribute("department", get);    return "success";  }}

（6）測試結果：