如何实现ehcache持久化
时间: 2023-07-20 16:18:41 浏览: 52
Ehcache提供了多种持久化方式,包括磁盘持久化和数据库持久化。下面分别介绍这两种持久化方式的实现方法。
1. 磁盘持久化
(1)配置Ehcache的缓存管理器,使其支持磁盘持久化:
```
<diskStore path="java.io.tmpdir"/>
<defaultCache
maxElementsInMemory="10000"
eternal="false"
timeToIdleSeconds="120"
timeToLiveSeconds="120"
overflowToDisk="true"
diskPersistent="true"
diskExpiryThreadIntervalSeconds="120"
memoryStoreEvictionPolicy="LRU"/>
```
其中,diskPersistent="true"表示启用磁盘持久化,diskExpiryThreadIntervalSeconds="120"表示缓存过期检查间隔时间为120秒。
(2)定义缓存数据对象和序列化方式:
```
public class User implements Serializable {
private static final long serialVersionUID = 1L;
private Long id;
private String name;
// 省略getter和setter
}
public class UserSerializer implements ElementValueSerializer<User> {
@Override
public User createValue(byte[] serializedValue) {
try (ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(serializedValue))) {
return (User) ois.readObject();
} catch (IOException | ClassNotFoundException e) {
throw new CacheException(e);
}
}
@Override
public byte[] serializeValue(User value) {
try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(value);
oos.flush();
return baos.toByteArray();
} catch (IOException e) {
throw new CacheException(e);
}
}
}
```
(3)使用缓存管理器创建缓存对象:
```
CacheManager cacheManager = new CacheManager();
Cache cache = new Cache(
new CacheConfiguration("userCache", 10000)
.eternal(false)
.timeToIdleSeconds(120)
.timeToLiveSeconds(120)
.overflowToDisk(true)
.diskPersistent(true)
.diskExpiryThreadIntervalSeconds(120)
.memoryStoreEvictionPolicy(MemoryStoreEvictionPolicy.LRU)
.persistence(new PersistenceConfiguration().strategy(PersistenceConfiguration.Strategy.LOCALTEMPSWAP))
.elementValueType(ElementValueType.SERIALIZATION)
.elementValueSerializer(new UserSerializer())
);
cacheManager.addCache(cache);
```
2. 数据库持久化
(1)配置Ehcache的缓存管理器,使其支持数据库持久化:
```
<diskStore path="java.io.tmpdir"/>
<defaultCache
maxElementsInMemory="10000"
eternal="false"
timeToIdleSeconds="120"
timeToLiveSeconds="120"
overflowToDisk="false"
diskPersistent="false"
diskExpiryThreadIntervalSeconds="120"
memoryStoreEvictionPolicy="LRU"/>
```
其中,overflowToDisk="false"表示禁用磁盘缓存,diskPersistent="false"表示禁用磁盘持久化。
(2)定义缓存数据对象和序列化方式:
```
public class User implements Serializable {
private static final long serialVersionUID = 1L;
private Long id;
private String name;
// 省略getter和setter
}
public class UserSerializer implements ElementValueSerializer<User> {
@Override
public User createValue(byte[] serializedValue) {
try (ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(serializedValue))) {
return (User) ois.readObject();
} catch (IOException | ClassNotFoundException e) {
throw new CacheException(e);
}
}
@Override
public byte[] serializeValue(User value) {
try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(value);
oos.flush();
return baos.toByteArray();
} catch (IOException e) {
throw new CacheException(e);
}
}
}
```
(3)使用缓存管理器创建缓存对象:
```
CacheManager cacheManager = new CacheManager();
Cache cache = new Cache(
new CacheConfiguration("userCache", 10000)
.eternal(false)
.timeToIdleSeconds(120)
.timeToLiveSeconds(120)
.overflowToDisk(false)
.diskPersistent(false)
.diskExpiryThreadIntervalSeconds(120)
.memoryStoreEvictionPolicy(MemoryStoreEvictionPolicy.LRU)
.persistence(new PersistenceConfiguration().strategy(PersistenceConfiguration.Strategy.LOCALRESTARTABLE))
.elementValueType(ElementValueType.SERIALIZATION)
.elementValueSerializer(new UserSerializer())
);
cacheManager.addCache(cache);
```
其中,persistence(new PersistenceConfiguration().strategy(PersistenceConfiguration.Strategy.LOCALRESTARTABLE))表示启用数据库持久化,elementValueType(ElementValueType.SERIALIZATION)和elementValueSerializer(new UserSerializer())表示使用序列化方式将缓存数据存储到数据库中。