Employee The entity class must be serialized public class Employee implements Serializable, otherwise it will report java.io.NotSerializableException abnormal.

4. Update @CachePut

@CachePut not only calls the method, but also updates the cache data; updates the cache synchronously. Simply put, the user modifies the data and updates the cached data synchronously.

Source code analysis: (Take a look, the accident is the same as @Cacheable, don’t explain too much, dog head body guard~~~)

public @interface CachePut {@AliasFor("cacheNames") String[] value() default {}; @AliasFor("value") String[] cacheNames() default {}; String key() default "" ; String keyGenerator() default ""; String cacheManager() default ""; String cacheResolver() default ""; String condition() default ""; String unless() default "";}

< strong>Exercise:

Note The value/cahceNames and key of the annotation must be updated The cache is the same as @Cacheable.

@CachePut(value = "emp" ,key = "#employee.id")public Employee updateEmp(Employee employee){ System.out.println("updateEmp:"+employee ); employeeMapper.updateEmp(employee); return employee;}

5. Clear @CacheEvict

@CachEvict The role of Mainly for method configuration, the cache can be cleared according to certain conditions.

Source code analysis:

public @interface CacheEvict {// Same as above Same as above @AliasFor("cacheNames") String[] value () default {}; @AliasFor("value") String[] cacheNames() default {}; String key() default ""; String keyGenerator() default ""; String cacheManager() default ""; String cacheResolver( ) default ""; String condition() default ""; // Specify to clear all data in this cache, example: @CachEvict(value=”emp”,allEntries=true) boolean allEntries() default false; /* * Example : @CachEvict(value=”emp”, beforeInvocation=true) * Indicates that the cache clear operation is executed before the method runs, regardless of whether the method is abnormal or not, the cache is cleared * * Example: @CachEvict(value=”emp”, beforeInvocation= false)(default) * Whether the cache clearing is performed before the method, the default means that the cache clearing operation is performed after the method is executed; if an exception occurs, the cache will not be cleared*/ boolean beforeInvocation() default false;)

< p>Exercise:

//Clear all caches after the method is called @CacheEvict(value="accountCache", allEntries=true)public void deleteEmp() {employeeMapper.deleteAll();}

6.Combination@Caching

Sometimes We may combine multiple Cache annotations. At this time, @Caching needs to combine multiple annotation tags.

Source code analysis:

public @interface Caching {// Used to specify multiple cache setting operations Cacheable[] cacheable() default {}; // Used to specify multiple cache update operations CachePut[] put() default {}; // Used to specify multiple cache invalidation operations CacheEvict[] evict() default {};}

< p>Practice it

// @Caching Define complex caching rules @Caching( cacheable = {@Cacheable(value="emp",key = " #lastName") }, put = {@CachePut(value="emp",key = "#result.id"), @CachePut(value="emp",key = "#result.email") })public Employee getEmpByLastName(String lastName){ return employeeMapper.getEmpByLastName(lastName);}

7. Global Configuration@CacheConfig

When we need to cache more places The more you come, you can use the @CacheConfig(cacheNames = {"emp"}) annotation to uniformly specify the value of value, then you can omit value, if you still write value in your method, then the value value of the method still prevails.

Source code analysis:

public @interface Caching {// Used to specify multiple cache setting operations Cacheable[] cacheable() default {}; // Used to specify multiple cache update operations CachePut[] put() default {}; // Used to specify multiple cache invalidation operations CacheEvict[] evict() default {};}

< p>Practice it:

@CacheConfig(cacheNames = {"emp"}, /*keyGenerator = "cacheKeyGenerator"*/)public class EmployeeServiceImpl implements EmployeeService {@Override @Cacheable(/*value ='emp'*/ key = "targetClass + methodName +#p0") public Employee getEmp(Integer id){ Employee emp = employeeMapper.getEmpById(id); return emp; }}< /pre> 
8. Primary key generation strategy keyGenerator
 
Exercise it:
 
Create CacheConfig configuration class< /p> 
@Configurationpublic class CacheConfig {/** * Generate cache primary key strategy (method name + parameters) * * @return KeyGenerator */ @Bean("cacheKeyGenerator") public KeyGenerator keyGenerator() { return (target, method, params) -> (method.getName() + "[" + Arrays.asList(params) + "]"); }}
You can specify the generation strategy in @CacheConfig, also You can specify the key generation strategy in @Cacheable/@CachePut/@CacheEvict
@CacheConfig(cacheNames = {"emp"}, keyGenerator = "cacheKeyGenerator") public class EmployeeServiceImpl implements EmployeeService {@Override @Cacheable(/*value ='emp',keyGenerator = "cacheKeyGenerator"*/) public Employee getEmp(Integer id){ Employee emp = employeeMapper.getEmpById(id); return emp; }}