spring 整合memcache

!:首先配置memcached.properties

#同时配置多台缓存服务器
memcached.cache.servers=192.138.11.165:11211,192.138.11.166:11211

#配置session的服务器
memcached.session.servers=192.138.11.168:11211,192.138.11.169:11211

2：在spring的配置文件中添加对memcache的支持
在spring的配置文件中添加，整合到spring中

<bean id="memcachedClient" class="net.spy.memcached.spring.MemcachedClientFactoryBean">
<property name="servers" value="$${memcached.cache.servers}"/>
<property name="protocol" value="BINARY"/>
<property name="transcoder">
<bean class="net.spy.memcached.transcoders.SerializingTranscoder">
<property name="compressionThreshold" value="1024"/>
</bean>
</property>
<property name="opTimeout" value="1000"/>
<property name="timeoutExceptionThreshold" value="1998"/>
<!-- <property name="hashAlg" value="KETAMA_HASH"/> -->
<property name="locatorType" value="CONSISTENT"/>
<property name="failureMode" value="Redistribute"/>
<property name="useNagleAlgorithm" value="false"/>
</bean>
 
<bean id="defaultCache" class="commons.cache.MemcachedCache">
<property name="memcachedClient" ref="memcachedClient" />
</bean>


3：封装了memcache的一些方法，方便操作

public interface Cache
{

    public abstract void set(String s, Object obj, int i);

    public abstract Object get(String s);

    public abstract Map getMulti(List list);

    public abstract Object[] getMulti(String as[]);

    public abstract boolean exists(String s);

    public abstract void delete(String s);
}


public class MemcachedCache
    implements Cache
{

    public MemcachedCache()
    {
    }

    public void set(String key, Object value, int expiry)
    {
        if(StringUtils.isEmpty(key) || value == null)
        {
            return;
        } else
        {
            memcachedClient.set(key, expiry * 60, value);
            return;
        }
    }

    public Object get(String key)
    {
        if(StringUtils.isEmpty(key))
            return Boolean.valueOf(false);
        Object o;
        try
        {
            o = memcachedClient.get(key);
        }
        catch(OperationTimeoutException e)
        {
            o = memcachedClient.get(key);
        }
        return o;
    }

    public Map getMulti(List keys)
    {
        if(keys == null || keys.size() == 0)
        {
            return new HashMap(0);
        } else
        {
            String strKeys[] = new String[keys.size()];
            strKeys = (String[])keys.toArray(strKeys);
            return memcachedClient.getBulk(strKeys);
        }
    }

    public Object[] getMulti(String keys[])
    {
        if(keys == null || keys.length == 0)
        {
            return new Object[0];
        } else
        {
            Map map = memcachedClient.getBulk(keys);
            return map.values().toArray();
        }
    }

    public void delete(String key)
    {
        if(StringUtils.isEmpty(key))
        {
            return;
        } else
        {
            memcachedClient.delete(key);
            return;
        }
    }

    public boolean exists(String key)
    {
        if(StringUtils.isEmpty(key))
            return false;
        else
            return memcachedClient.get(key) != null;
    }

    public void setMemcachedClient(MemcachedClient memcachedClient)
    {
        this.memcachedClient = memcachedClient;
    }

    private MemcachedClient memcachedClient;
}

4：在项目运用memcache

配置好memacache的环境了，就可以在项目中应用了

public class TestMemcacheService {


private MemcachedCache defaultCache;
private final static String KEY = "modul_methodname";
//需要spring注入上面配置好的bean的ID为defaultCache的bean
public void setDefaultCache(MemcachedCache defaultCache) {
this.defaultCache = defaultCache;
}

String sql = null;
//首先从缓存中取数据，如果缓存中没有，说明数据过期了，这时候可以去数据库查询新的数据，再添加到缓存中，
//这样可以很大程度上提高了后台响应时间。
if (null != defaultCache.get(KEY)) {
return (List<Item>) defaultCache.get(KEY);
}
sql = "select * " + " from  test order by match_date desc limit 50 ";
executeQuery(sql, 1);
....
defaultCache.set(KEY, list, 15);
return list;

}

评论

1 楼 zhijiandedaima 2015-04-22  

为什么我的defaultCache是空，空指针异常啊