本文整理了Java中com.github.benmanes.caffeine.cache.Cache.getIfPresent()方法的一些代码示例，展示了Cache.getIfPresent()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Cache.getIfPresent()方法的具体详情如下：
包路径：com.github.benmanes.caffeine.cache.Cache
类名称：Cache
方法名：getIfPresent

Cache.getIfPresent介绍

[英]Returns the value associated with the key in this cache, or null if there is no cached value for the key.
[中]返回与此缓存中的键关联的值，如果没有该键的缓存值，则返回null。

代码示例

代码示例来源：origin: spring-projects/spring-framework

@Override
@Nullable
protected Object lookup(Object key) {
  return this.cache.getIfPresent(key);
}

代码示例来源：origin: apache/incubator-druid

@Override
public byte[] get(NamedKey key)
{
 return deserialize(cache.getIfPresent(key));
}

代码示例来源：origin: ben-manes/caffeine

@Override @Nullable
public V getIfPresent(Object key) {
 return cache.getIfPresent(key);
}

代码示例来源：origin: dropwizard/dropwizard

/**
 * Gets the human friendly location of where the violation was raised.
 */
public static String getMessage(ConstraintViolation<?> v, Invocable invocable) {
  final Pair<Path, ? extends ConstraintDescriptor<?>> of =
      Pair.of(v.getPropertyPath(), v.getConstraintDescriptor());
  final String cachePrefix = PREFIX_CACHE.getIfPresent(of);
  if (cachePrefix == null) {
    final String prefix = calculatePrefix(v, invocable);
    PREFIX_CACHE.put(of, prefix);
    return prefix + v.getMessage();
  }
  return cachePrefix + v.getMessage();
}

代码示例来源：origin: ben-manes/caffeine

@Nullable
protected static Expirable<Integer> getExpirable(
  CacheProxy<Integer, Integer> cache, Integer key) {
 return cache.cache.getIfPresent(key);
}

代码示例来源：origin: ben-manes/caffeine

@Test(dataProvider = "caches")
@CacheSpec(keys = ReferenceType.WEAK, population = Population.FULL)
public void identity_keys(Cache<Integer, Integer> cache, CacheContext context) {
 @SuppressWarnings("deprecation")
 Integer key = new Integer(context.firstKey());
 assertThat(cache.getIfPresent(key), is(nullValue()));
}

代码示例来源：origin: ben-manes/caffeine

@CheckNoWriter
@Test(dataProvider = "caches")
@CacheSpec(removalListener = { Listener.DEFAULT, Listener.REJECTING },
  population = { Population.SINGLETON, Population.PARTIAL, Population.FULL })
public void getIfPresent_present(Cache<Integer, Integer> cache, CacheContext context) {
 assertThat(cache.getIfPresent(context.firstKey()), is(not(nullValue())));
 assertThat(cache.getIfPresent(context.middleKey()), is(not(nullValue())));
 assertThat(cache.getIfPresent(context.lastKey()), is(not(nullValue())));
 assertThat(context, both(hasMissCount(0)).and(hasHitCount(3)));
 assertThat(context, both(hasLoadSuccessCount(0)).and(hasLoadFailureCount(0)));
}

代码示例来源：origin: ben-manes/caffeine

@Test(dataProvider = "caches")
@CacheSpec(keys = ReferenceType.STRONG, values = {ReferenceType.WEAK, ReferenceType.SOFT},
  expireAfterAccess = Expire.DISABLED, expireAfterWrite = Expire.DISABLED,
  maximumSize = Maximum.DISABLED, weigher = CacheWeigher.DEFAULT,
  population = Population.FULL, stats = Stats.ENABLED, removalListener = Listener.CONSUMING)
public void getIfPresent(Cache<Integer, Integer> cache, CacheContext context) {
 Integer key = context.firstKey();
 context.clear();
 GcFinalization.awaitFullGc();
 assertThat(cache.getIfPresent(key), is(nullValue()));
}

代码示例来源：origin: ben-manes/caffeine

@Override
public void record(long key) {
 Object value = cache.getIfPresent(key);
 if (value == null) {
  if (cache.estimatedSize() == maximumSize) {
   policyStats.recordEviction();
  }
  cache.put(key, key);
  policyStats.recordMiss();
 } else {
  policyStats.recordHit();
 }
}

代码示例来源：origin: ben-manes/caffeine

@Test(dataProvider = "caches")
@CacheSpec(implementation = Implementation.Caffeine, population = Population.FULL,
  expiry = CacheExpiry.WRITE, expiryTime = Expire.ONE_MINUTE)
public void putIfAbsent_insert(Cache<Integer, Integer> cache, CacheContext context,
  VarExpiration<Integer, Integer> expireAfterVar) {
 Integer key = context.absentKey();
 Integer value = context.absentValue();
 assertThat(expireAfterVar.putIfAbsent(key, value, Duration.ofMinutes(2L)), is(true));
 assertThat(cache.getIfPresent(key), is(value));
 assertThat(expireAfterVar.getExpiresAfter(key), is(Optional.of(Duration.ofMinutes(2L))));
 context.ticker().advance(90, TimeUnit.SECONDS);
 cache.cleanUp();
 assertThat(cache.estimatedSize(), is(1L));
}

代码示例来源：origin: ben-manes/caffeine

@CheckNoWriter @CheckNoStats
@CacheSpec(removalListener = { Listener.DEFAULT, Listener.REJECTING })
@Test(dataProvider = "caches", expectedExceptions = NullPointerException.class)
public void getIfPresent_nullKey(Cache<Integer, Integer> cache, CacheContext context) {
 cache.getIfPresent(null);
}

代码示例来源：origin: ben-manes/caffeine

@Test(dataProvider = "caches")
@CacheSpec(implementation = Implementation.Caffeine, population = Population.FULL,
  expiry = CacheExpiry.WRITE, expiryTime = Expire.ONE_MINUTE)
public void putIfAbsent_present(Cache<Integer, Integer> cache, CacheContext context,
  VarExpiration<Integer, Integer> expireAfterVar) {
 Integer key = context.firstKey();
 Integer value = context.absentValue();
 assertThat(expireAfterVar.putIfAbsent(key, value, Duration.ofMinutes(2L)), is(false));
 assertThat(cache.getIfPresent(key), is(context.original().get(key)));
 assertThat(expireAfterVar.getExpiresAfter(key), is(Optional.of(Duration.ofMinutes(1L))));
 context.ticker().advance(90, TimeUnit.SECONDS);
 cache.cleanUp();
 assertThat(cache.estimatedSize(), is(0L));
}

代码示例来源：origin: ben-manes/caffeine

@Test(dataProvider = "caches")
@CacheSpec(implementation = Implementation.Caffeine, population = Population.FULL,
  expiry = CacheExpiry.WRITE, expiryTime = Expire.ONE_MINUTE)
public void put_insert(Cache<Integer, Integer> cache, CacheContext context,
  VarExpiration<Integer, Integer> expireAfterVar) {
 Integer key = context.absentKey();
 Integer value = context.absentValue();
 expireAfterVar.put(key, value, Duration.ofMinutes(2L));
 assertThat(cache.getIfPresent(key), is(value));
 assertThat(expireAfterVar.getExpiresAfter(key), is(Optional.of(Duration.ofMinutes(2L))));
 context.ticker().advance(90, TimeUnit.SECONDS);
 cache.cleanUp();
 assertThat(cache.estimatedSize(), is(1L));
}

代码示例来源：origin: ben-manes/caffeine

@Test(dataProvider = "caches")
@CacheSpec(implementation = Implementation.Caffeine, population = Population.FULL,
  expiry = CacheExpiry.WRITE, expiryTime = Expire.ONE_MINUTE)
public void put_replace(Cache<Integer, Integer> cache, CacheContext context,
  VarExpiration<Integer, Integer> expireAfterVar) {
 Integer key = context.firstKey();
 Integer value = context.absentValue();
 expireAfterVar.put(key, value, Duration.ofMinutes(2L));
 assertThat(cache.getIfPresent(key), is(value));
 assertThat(expireAfterVar.getExpiresAfter(key), is(Optional.of(Duration.ofMinutes(2L))));
 context.ticker().advance(90, TimeUnit.SECONDS);
 cache.cleanUp();
 assertThat(cache.estimatedSize(), is(1L));
}

代码示例来源：origin: ben-manes/caffeine

@Test(dataProvider = "caches")
@CacheSpec(removalListener = { Listener.DEFAULT, Listener.REJECTING })
public void put_insert(Cache<Integer, Integer> cache, CacheContext context) {
 cache.put(context.absentKey(), context.absentValue());
 assertThat(cache.estimatedSize(), is(context.initialSize() + 1));
 assertThat(cache.getIfPresent(context.absentKey()), is(context.absentValue()));
}

代码示例来源：origin: ben-manes/caffeine

@CheckNoWriter
@Test(dataProvider = "caches")
@CacheSpec(population = { Population.SINGLETON, Population.PARTIAL, Population.FULL })
public void put_replace_sameValue(Cache<Integer, Integer> cache, CacheContext context) {
 for (Integer key : context.firstMiddleLastKeys()) {
  Integer value = context.original().get(key);
  cache.put(key, value);
  assertThat(cache.getIfPresent(key), is(value));
 }
 assertThat(cache.estimatedSize(), is(context.initialSize()));
 int count = context.firstMiddleLastKeys().size();
 if (context.isGuava() || context.isAsync()) {
  assertThat(cache, hasRemovalNotifications(context, count, RemovalCause.REPLACED));
 }
}

代码示例来源：origin: ben-manes/caffeine

@CheckNoWriter
@Test(dataProvider = "caches")
@CacheSpec(removalListener = { Listener.DEFAULT, Listener.REJECTING })
public void getIfPresent_absent(Cache<Integer, Integer> cache, CacheContext context) {
 assertThat(cache.getIfPresent(context.absentKey()), is(nullValue()));
 assertThat(context, both(hasMissCount(1)).and(hasHitCount(0)));
 assertThat(context, both(hasLoadSuccessCount(0)).and(hasLoadFailureCount(0)));
}

代码示例来源：origin: ben-manes/caffeine

@Test(dataProvider = "caches")
@CacheSpec(population = { Population.SINGLETON, Population.PARTIAL, Population.FULL })
public void put_replace_differentValue(Cache<Integer, Integer> cache, CacheContext context) {
 for (Integer key : context.firstMiddleLastKeys()) {
  cache.put(key, context.absentValue());
  assertThat(cache.getIfPresent(key), is(context.absentValue()));
  verifyWriter(context, (verifier, writer) -> {
   verifier.wrote(key, context.absentValue());
  });
 }
 assertThat(cache.estimatedSize(), is(context.initialSize()));
 int count = context.firstMiddleLastKeys().size();
 assertThat(cache, hasRemovalNotifications(context, count, RemovalCause.REPLACED));
}

代码示例来源：origin: ben-manes/caffeine

@CacheSpec(implementation = Implementation.Caffeine,
  population = Population.FULL, expiry = CacheExpiry.MOCKITO)
@Test(dataProvider = "caches", expectedExceptions = ExpirationException.class)
public void getIfPresent_expiryFails(Cache<Integer, Integer> cache, CacheContext context) {
 try {
  context.ticker().advance(1, TimeUnit.HOURS);
  when(context.expiry().expireAfterRead(any(), any(), anyLong(), anyLong()))
    .thenThrow(ExpirationException.class);
  cache.getIfPresent(context.firstKey());
 } finally {
  context.ticker().advance(-1, TimeUnit.HOURS);
  assertThat(cache.asMap(), equalTo(context.original()));
 }
}

代码示例来源：origin: ben-manes/caffeine

@Test(dataProvider = "caches")
@CacheSpec(removalListener = { Listener.DEFAULT, Listener.REJECTING })
public void put_insert(AsyncCache<Integer, Integer> cache, CacheContext context) {
 CompletableFuture<Integer> value = CompletableFuture.completedFuture(context.absentValue());
 cache.put(context.absentKey(), value);
 assertThat(cache.synchronous().estimatedSize(), is(context.initialSize() + 1));
 assertThat(context, both(hasMissCount(0)).and(hasHitCount(0)));
 assertThat(context, both(hasLoadSuccessCount(1)).and(hasLoadFailureCount(0)));
 assertThat(cache.synchronous().getIfPresent(context.absentKey()), is(context.absentValue()));
}