目录
定义
抽象⼯⼚模式与⼯⼚⽅法模式虽然主要意图都是为了解决，接⼝选择问题。但在实现上，抽象⼯⼚是⼀个中⼼⼯⼚，创建其他⼯⼚的模式。
Redis 集群升级
随着这次的升级，可以预⻅的问题会有；
1. 很多服务⽤到了Redis需要⼀起升级到集群。
2. 需要兼容集群A和集群B，便于后续的灾备。
3. 两套集群提供的接⼝和⽅法各有差异，需要做适配。
4. 不能影响到⽬前正常运⾏的系统。
模拟单机服务 RedisUtils
模拟集群 EGM
模拟集群 IIR
定义使⽤接⼝
public interface CacheService {
String get(final String key);
void set(String key, String value);
void set(String key, String value, long timeout, TimeUnit timeUnit);
void del(String key);
}实现调⽤代码
public class CacheServiceImpl implements CacheService {
private RedisUtils redisUtils = new RedisUtils();
public String get(String key) {
return redisUtils.get(key);
}
public void set(String key, String value) {
redisUtils.set(key, value);
}
public void set(String key, String value, long timeout, TimeUnit timeUnit) {
redisUtils.set(key, value, timeout, timeUnit);
}
public void del(String key) {
redisUtils.del(key);
}
}代码实现
定义适配接⼝
public interface ICacheAdapter {
String get(String key);
void set(String key, String value);
void set(String key, String value, long timeout, TimeUnit timeUnit);
void del(String key);
}实现集群使⽤服务
EGMCacheAdapter
public class EGMCacheAdapter implements ICacheAdapter {
private EGM egm = new EGM();
public String get(String key) {
return egm.gain(key);
}
public void set(String key, String value) {
egm.set(key, value);
}
public void set(String key, String value, long timeout, TimeUnit timeUnit) {
egm.setEx(key, value, timeout, timeUnit);
}
public void del(String key) {
egm.delete(key);
}
}IIRCacheAdapter
public class IIRCacheAdapter implements ICacheAdapter {
private IIR iir = new IIR();
public String get(String key) {
return iir.get(key);
}
public void set(String key, String value) {
iir.set(key, value);
}
public void set(String key, String value, long timeout, TimeUnit timeUnit) {
iir.setExpire(key, value, timeout, timeUnit);
}
public void del(String key) {
iir.del(key);
}
}定义抽象⼯程代理类和实现
JDKProxy
public static <T> T getProxy(Class<T> interfaceClass, ICacheAdapter cacheAdapter) throws Exception {
InvocationHandler handler = new JDKInvocationHandler(cacheAdapter);
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
Class<?>[] classes = interfaceClass.getInterfaces();
return (T) Proxy.newProxyInstance(classLoader, new Class[]{classes[0]}, handler);
}JDKInvocationHandler
public class JDKInvocationHandler implements InvocationHandler {
private ICacheAdapter cacheAdapter;
public JDKInvocationHandler(ICacheAdapter cacheAdapter) {
this.cacheAdapter = cacheAdapter;
}
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
return ICacheAdapter.class.getMethod(method.getName(), ClassLoaderUtils.getClazzByArgs(args)).invoke(cacheAdapter, args);
}
}测试验证
@Test
public void test_CacheService() throws Exception {
CacheService proxy_EGM = JDKProxy.getProxy(CacheServiceImpl.class, new EGMCacheAdapter());
proxy_EGM.set("user_name_01","⼩亮哥");
String val01 = proxy_EGM.get("user_name_01");
System.out.println(val01);
CacheService proxy_IIR = JDKProxy.getProxy(CacheServiceImpl.class, new IIRCacheAdapter());
proxy_IIR.set("user_name_01","⼩亮哥");
String val02 = proxy_IIR.get("user_name_01");
System.out.println(val02);
}