使用springboot的cache功能:
1.在启动类上加注解@enableCaching,启用缓存
2.在需要缓存的方法上加入对应的注解,具体如下:
/*
* 1.@Cacheable(cacheNames = "car", key = "#name")
* 将方法的返回值 保存 在缓存“car”中,键由key指定,值是方法的返回值
* 2.@CachePut(cacheNames = "car", key = "#car.name")
* 使用方法的返回值 更新 缓存“car”中,键为key的值
* 3.@CacheEvict(cacheNames = "car", allEntries = true)
* 根据key和condition删除缓存,如果指定allEntries为true,则删除缓存中所有的对象
*/
springboot实例如下:
实体类
package com.example.demo7cache.entity;
import java.time.LocalTime;
/**
* @author Created by yawn on 2017-10-24 16:42
*/
public class Car {
private String name;
private LocalTime time;
public Car() {
}
public Car(String name) {
this.name = name;
}
public Car(String name, LocalTime time) {
this.name = name;
this.time = time;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public LocalTime getTime() {
return time;
}
public void setTime(LocalTime time) {
this.time = time;
}
@Override
public String toString() {
return "Car{" +
"name='" + name + '\'' +
", time=" + time +
'}';
}
}
缓存类
package com.example.demo7cache.cache;
import com.example.demo7cache.entity.Car;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;
import java.time.LocalTime;
import java.util.ArrayList;
import java.util.List;
/**
* @author Created by yawn on 2017-10-24 16:44
*/
@Service
public class CarService {
// 以下三个方法为查询方法
/*
* 1.@Cacheable(cacheNames = "car", key = "#name")
* 将方法的返回值 保存 在缓存“car”中,键由key指定,值是方法的返回值
* 2.@CachePut(cacheNames = "car", key = "#car.name")
* 使用方法的返回值 更新 缓存“car”中,键为key的值
* 3.@CacheEvict(cacheNames = "car", allEntries = true)
* 根据key和condition删除缓存,如果指定allEntries为true,则删除缓存中所有的对象
*/
@Cacheable(cacheNames = "car", key = "#name")
public Car getByName(String name) {
System.err.println("查询car");
return new Car(name, LocalTime.now());
}
@Cacheable(cacheNames = "car", key = "#car.name")
public Car getByCar(Car car) {
System.err.println("查询car");
return new Car("getByCar", LocalTime.now());
}
@Cacheable(cacheNames = "carList")
public List<Car> getAll() {
System.err.println("查询carList");
List<Car> carList = new ArrayList<>();
carList.add(new Car("aaa", LocalTime.now()));
carList.add(new Car("bbb", LocalTime.now()));
carList.add(new Car("ccc", LocalTime.now()));
return carList;
}
/**
* save方法:
* 1.将返回值写入car缓存
* 2.清空carList缓存中所有对象
*/
@Cacheable(cacheNames = "car", key = "#car.name")
@CacheEvict(cacheNames = "carList", allEntries = true)
public Car save(Car car) {
System.err.println("保存car");
return car;
}
/**
* update方法
* 1.更新缓存car
* 2.清空carList缓存中所有对象
*/
@CachePut(cacheNames = "car", key = "#car.name")
@CacheEvict(cacheNames = "carList", allEntries = true)
public Car update(Car car) {
System.err.println("更新car");
return new Car("yawn", LocalTime.now());
}
/**
* delete方法
* 1.删除car缓存和carList缓存中的所有对象
*/
@CacheEvict(cacheNames = {"car", "carList"}, allEntries = true)
public void delete(String name) {
System.err.println("删除car");
}
}
测试类
package com.example.demo7cache;
import com.example.demo7cache.cache.CarService;
import com.example.demo7cache.entity.Car;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import javax.annotation.Resource;
import java.time.LocalTime;
/**
* @author Created by yawn on 2017-10-24 16:58
*/
@RunWith(SpringRunner.class)
@SpringBootTest
public class CarServiceTest {
@Resource
private CarService carService;
/**
* 测试第二次从缓存中查询
*/
@Test
public void test1() {
System.out.println(carService.getByName("yawn"));
System.out.println(carService.getByName("yawn"));
System.out.println(carService.getAll());
System.out.println(carService.getAll());
}
/**
* 测试不同方法查询从同一缓存中查询
*/
@Test
public void test2() {
System.out.println(carService.getByName("yawn"));
System.out.println(carService.getByCar(new Car("yawn")));
}
/**
* 测试保存后的写入缓存的查询
*/
@Test
public void test3() throws InterruptedException {
System.out.println(carService.save(new Car("yawn", LocalTime.now())));
Thread.sleep(998);
System.out.println(carService.getByName("yawn"));
}
/**
* 测试更新后对car缓存的更新
*/
@Test
public void test4() throws InterruptedException {
System.out.println(carService.getByName("yawn"));
Thread.sleep(998);
System.out.println(carService.update(new Car("yawn", LocalTime.now())));
Thread.sleep(998);
System.out.println(carService.getByName("yawn"));
}
/**
* 更新后对carList缓存的删除
*/
@Test
public void test5() throws InterruptedException {
System.out.println(carService.getAll());
System.out.println(carService.update(new Car("yawn")));
Thread.sleep(998);
System.out.println(carService.getAll());
}
/**
* 删除后对两个缓存中 所有实体的删除
*/
@Test
public void test7() throws InterruptedException {
System.out.println(carService.getAll());
System.out.println(carService.getByName("yawn"));
carService.delete("yyy");
Thread.sleep(988);
System.out.println(carService.getAll());
System.out.println(carService.getByName("yawn"));
}
}