@CheckReturnValue @ParametersAreNonnullByDefault

Package com.google.common.base

Basic utility libraries and interfaces.

This package is a part of the open-source Guava library.

Contents

The classes in this package that are most commonly useful are:

String utilities

• Ascii
• CaseFormat
• CharMatcher
• Splitter
• Strings

Function types

• Converter
• Equivalence

Other

• Enums
• MoreObjects
• Preconditions
• StandardSystemProperty
• Stopwatch
• Throwables
• Verify

The rest

This package also contains some classes with niche use cases (e.g., Utf8 and Defaults), as well as a number of classes that have been superseded by additions to the JDK.

Interface Summary

Interface	Description
FinalizableReference	Implemented by references that have code to run after garbage collection of their referents.
Function<F extends @Nullable Object,T extends @Nullable Object>	Legacy version of java.util.function.Function.
Predicate<T extends @Nullable Object>	Legacy version of java.util.function.Predicate.
Supplier<T extends @Nullable Object>	Legacy version of java.util.function.Supplier.

Class Summary

Class	Description
Ascii	Static methods pertaining to ASCII characters (those in the range of values 0x00 through 0x7F), and to strings containing such characters.
CharMatcher	Determines a true or false value for any Java char value, just as Predicate does for any Object.
Charsets	Contains constant definitions for the six standard Charset instances, which are guaranteed to be supported by all Java platform implementations.
Converter<A,B>	A function from A to B with an associated reverse function from B to A; used for converting back and forth between different representations of the same information.
Defaults	This class provides default values for all Java types, as defined by the JLS.
Enums	Utility methods for working with Enum instances.
Equivalence<T>	A strategy for determining whether two instances are considered equivalent, and for computing hash codes in a manner consistent with that equivalence.
Equivalence.Wrapper<T extends @Nullable Object>	Wraps an object so that Equivalence.Wrapper.equals(Object) and Equivalence.Wrapper.hashCode() delegate to an Equivalence.
FinalizablePhantomReference<T>	Phantom reference with a finalizeReferent() method which a background thread invokes after the garbage collector reclaims the referent.
FinalizableReferenceQueue	A reference queue with an associated background thread that dequeues references and invokes FinalizableReference.finalizeReferent() on them.
FinalizableSoftReference<T>	Soft reference with a finalizeReferent() method which a background thread invokes after the garbage collector reclaims the referent.
FinalizableWeakReference<T>	Weak reference with a finalizeReferent() method which a background thread invokes after the garbage collector reclaims the referent.
Functions	Static utility methods pertaining to com.google.common.base.Function instances; see that class for information about migrating to java.util.function.
Joiner	An object which joins pieces of text (specified as an array, Iterable, varargs or even a Map) with a separator.
Joiner.MapJoiner	An object that joins map entries in the same manner as Joiner joins iterables and arrays.
MoreObjects	Helper functions that operate on any Object, and are not already provided in Objects.
MoreObjects.ToStringHelper	Support class for MoreObjects.toStringHelper(java.lang.Object).
Objects	Helper functions that can operate on any Object.
Optional<T>	An immutable object that may contain a non-null reference to another object.
Preconditions	Static convenience methods that help a method or constructor check whether it was invoked correctly (that is, whether its preconditions were met).
Predicates	Static utility methods pertaining to Predicate instances.
Splitter	Extracts non-overlapping substrings from an input string, typically by recognizing appearances of a separator sequence.
Splitter.MapSplitter	An object that splits strings into maps as Splitter splits iterables and lists.
Stopwatch	An object that accurately measures elapsed time: the measured duration between two successive readings of "now" in the same process.
Strings	Static utility methods pertaining to String or CharSequence instances.
Suppliers	Useful suppliers.
Throwables	Static utility methods pertaining to instances of Throwable.
Ticker	A time source; returns a time value representing the number of nanoseconds elapsed since some fixed but arbitrary point in time.
Utf8	Low-level, high-performance utility methods related to the UTF-8 character encoding.
Verify	Static convenience methods that serve the same purpose as Java language assertions, except that they are always enabled.

Enum Summary

Enum	Description
CaseFormat	Utility class for converting between various ASCII case formats.
StandardSystemProperty	Represents a standard system property.

Exception Summary

Exception	Description
VerifyException	Exception thrown upon the failure of a verification check, including those performed by the convenience methods of the Verify class.