本文整理了Java中com.apollographql.apollo.api.internal.Optional.absent()方法的一些代码示例，展示了Optional.absent()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。Optional.absent()方法的具体详情如下：
包路径：com.apollographql.apollo.api.internal.Optional
类名称：Optional
方法名：absent

Optional.absent介绍

[英]Returns an Optional instance with no contained reference.

Comparison to java.util.Optional: this method is equivalent to Java 8's Optional.empty.
[中]返回不包含引用的可选实例。
与java的比较。util。可选：此方法相当于Java8的可选方法。空的

代码示例

代码示例来源：origin: apollographql/apollo-android

@Override
public <V> Optional<V> transform(Function<? super T, V> function) {
 checkNotNull(function);
 return Optional.absent();
}

代码示例来源：origin: apollographql/apollo-android

/**
 * If {@code nullableReference} is non-null, returns an {@code Optional} instance containing that reference; otherwise
 * returns {@link Optional#absent}.
 *
 * <p><b>Comparison to {@code java.util.Optional}:</b> this method is equivalent to Java 8's {@code
 * Optional.ofNullable}.
 */
public static <T> Optional<T> fromNullable(@Nullable T nullableReference) {
 return (nullableReference == null)
   ? Optional.<T>absent()
   : new Present<T>(nullableReference);
}

代码示例来源：origin: apollographql/apollo-android

@Override public Optional<T> apply(Action<T> action) {
 checkNotNull(action);
 return Optional.absent();
}

代码示例来源：origin: apollographql/apollo-android

@Override public <V> Optional<V> map(Function<? super T, V> function) {
 checkNotNull(function);
 return Optional.absent();
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testMapAbssentFunctionReturnsNull() {
 assertEquals(Optional.absent(),
   Optional.absent().map(
     new Function<Object, Object>() {
      @Override public Object apply(Object input) {
       return null;
      }
     }));
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testFlatMapAbsent() {
 assertEquals(Optional.absent(), Optional.absent().flatMap(new Function<Object, Optional<String>>() {
  @NotNull @Override public Optional<String> apply(@NotNull Object o) {
   return Optional.of(o.toString());
  }
 }));
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testTransformAbssentFunctionReturnsNull() {
 assertEquals(Optional.absent(),
   Optional.absent().transform(
     new Function<Object, Object>() {
      @Override public Object apply(Object input) {
       return null;
      }
     }));
}

代码示例来源：origin: apollographql/apollo-android

@Test
 public void testFlatMapAbssentFunctionReturnsNull() {
  assertEquals(Optional.absent(), Optional.absent().flatMap(new Function<Object, Optional<Object>>() {
   @NotNull @Override public Optional<Object> apply(@NotNull Object o) {
    return null;
   }
  }));
 }
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testAsSetAbsent() {
 assertTrue("Returned set should be empty", Optional.absent().asSet().isEmpty());
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testTransformAbsent() {
 assertEquals(Optional.absent(), Optional.absent().transform(Functions.identity()));
 assertEquals(Optional.absent(), Optional.absent().transform(Functions.toStringFunction()));
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testMapAbsent() {
 assertEquals(Optional.absent(), Optional.absent().map(Functions.identity()));
 assertEquals(Optional.absent(), Optional.absent().map(Functions.toStringFunction()));
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testEqualsAndHashCodeAbsent() {
 assertEquals(Optional.<String>absent(), Optional.<Integer>absent());
 assertEquals(Optional.absent().hashCode(), Optional.absent().hashCode());
 assertThat(Optional.absent().hashCode())
   .isNotEqualTo(Optional.of(0).hashCode());
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testAsSetAbsentIsImmutable() {
 Set<Object> absentAsSet = Optional.absent().asSet();
 try {
  absentAsSet.add("foo");
  fail();
 } catch (UnsupportedOperationException ignore) {
 }
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testFromNullableNull() {
 // not promised by spec, but easier to test
 assertSame(Optional.absent(), Optional.fromNullable(null));
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testGetAbsent() {
 Optional<String> optional = Optional.absent();
 try {
  optional.get();
  fail();
 } catch (IllegalStateException ignore) {
 }
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testAbsent() {
 Optional<String> optionalName = Optional.absent();
 assertFalse(optionalName.isPresent());
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testOrTAbsent() {
 assertEquals("default", Optional.absent().or("default"));
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testToStringAbsent() {
 assertEquals("Optional.absent()", Optional.absent().toString());
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testOrOptionalAbsent() {
 assertEquals(Optional.of("fallback"), Optional.absent().or(Optional.of("fallback")));
}

代码示例来源：origin: apollographql/apollo-android

@Test
public void testEqualsAndHashCodePresent() {
 assertEquals(Optional.of("training"), Optional.of("training"));
 assertFalse(Optional.of("a").equals(Optional.of("b")));
 assertFalse(Optional.of("a").equals(Optional.absent()));
 assertEquals(Optional.of("training").hashCode(), Optional.of("training").hashCode());
}