Appendable – Can append to instances of this type; implicitly supported by a Go slice.

AutoCloseable – Can be closed by try with resources; no direct Go equivalent.

CharSequence – A sequence of characters (such as a String or StringBuilder); no direct Go equivalent.

Cloneable – Implements Object.clone(); no direct Go equivalent.

Comparable<T> – Can support a compareTo() method; no direct Go equivalent; many types are implicitly comparable.

Iterable<T> – Can be iterated; some Go types: array, slice, map, channel.

Readable – Can read characters into a buffer; io.Reader for UTF-8.

Runnable – Can be run as a thread body; in Go, any function can be run as a goroutine.

Boolean – Boolean wrapper; not needed on Go collections.

Byte – Byte wrapper; not needed on Go collections.

Character – Char wrapper; not needed on Go collections.

Class<T> – A runtime view of a class; a feature for reflection; Go has a reflection package.

ClassLoader – Loads/manages classes at runtime; not needed in Go, no runtime classes.

Double – Double wrapper; not needed on Go collections.

Enum<E extends Enum<E>> – Base type of all enum types; not needed in Go (int is the base of most Go enums).

Float – Float wrapper; not needed on Go collections.

Integer – Int wrapper; not needed on Go collections.

Long – Long wrapper; not needed on Go collections.

Math – A class with a set of math utilities; Go has a similar math package.

Module – A runtime view of a module; no direct Go equivalent.

Number – A superclass of numeric wrapper types; no direct Go equivalent.

Object – A superclass of all object types; no direct Go equivalent; interface{} is closest.

Package – A runtime view of a package; no direct Go equivalent.

Process – A runtime view of an external program; a Go exec package has similar.

ProcessBuilder – A helper to run an external program; a Go exec package has similar.

Record (new) – A structure like class; Go has the struct type.

Runtime – Utilities to manage a running program; Go has a runtime package.

RuntimePermission – Means to control access to a function in classes; Go has no equivalent.

SecurityManager – Means to control access to a function in classes; Go has no equivalent.

Short – Short wrapper; not needed on Go collections.

StackTraceElement – Describes a call stack element; Go has a similar struct type.

StackWalker – Crawls a stack; no direct Go equivalent; one can be written.

StrictMath – Like a Math class with more rules on how the algorithms work; no direct Go equivalent.

String – A string type; Go has a string type and strings, strconv, and fmt packages.

StringBuffer, StringBuilder – A mutable string type; Go has a strings.Builder type.

System – Utilities to manage a running program; Go has runtime, time, and io packages.

Thread – An operating system thread; no direct Go equivalent; go has goroutines.

ThreadGroup – A collection of related threads; no direct Go equivalent.

ThreadLocal<T> – A variable with thread-dependent values; no direct Go equivalent; can be made.

Throwable – A type that can be thrown; Go has panics.

Void – No Go equivalent; Go functions can return nothing (vs. void).

math.BigInteger – Indefinite precision integer; Go has a math.Int type.

math.BigDecimal – Indefinite precision decimal float value; Go has math.Float (but it is binary, not decimal).

PrintStream err – STDERR – Go os.Stderr

InputStream in – STDIN – Go os.Stdin

PrintStream out – STDOUT – Go os.Stdout

arraycopy(…) – Copy an array; Go operator: array[:] and copy(..) function

clearProperty(String key) – Empty system property

console() – Get access to the OS console

currentTimeMillis() – Get the current Epoch time; Go time.Now()

exit(…) – See the Runtime class; Go os.Exit(...)

gc() – See the Runtime class; Go runtime.GC()

getenv() – Get all Environment values; Go os.Environ()

getenv(…) – Get a single Environment value

getLogger(…) – Get a named logger ; Go log package

getProperties() – Get all properties

getProperty(…) – Get a named property

getSecurityManager() – Get a JVM security manager

identityHashCode(Object x) – Get an object’s identity; in Go, use the &x operator

lineSeparator() – Get an OS line separator (e.g., NL, CR+NL)

load(…), loadLibrary(…) – See the Runtime class

nanoTime() – Get elapsed time in nanoseconds; Go time package

runFinalization() – See the Runtime class

setErr(…) – Change STDERR

setIn(…) – Change STDIN

setOut(…) – Change STDOUT

setProperties(Properties props) – Set many system properties

setProperty(String key, String value) – Set the system property

setSecurityManager(…) – Set a JVM security manager

addShutdownHook(…) – Run a thread at the exit of JVM; no direct Go equivalent; Go can trap OS signals; Go can trap panics.

availableProcessors() – Get CPU (core) count; Go runtime.NumCPU().

exec(...) – Family of methods to launch external process; Go exec.Cmd.

exit(…) – Exit the JVM with cleanup; no Go equivalent; Go can approx. by using os.Exit().

freeMemory() – Get free memory available to JVM; Go runtime.MemStats.

gc() – Run a garbage collection; Go runtime.GC ().

getRuntime() – Get this class’s singleton; no Go equivalent.

halt(…) – Exit JVM with no cleanup; Go os.Exit(...).

load(…), loadLibrary​(…) – Load a foreign code library; no Go equivalent.

maxMemory()– Get maximum memory available to JVM; Go runtime.MemStats.

removeShutdownHook(…) – Remove the exit hook; no Go equivalent.

runFinalization() – Force Object finalization; no Go equivalent.

totalMemory() – Get memory used by JVM; Go runtime.MemStats.

version() – Get the JVM version; Go runtime.version().

Closeable – Can be closed. Used by try with resources; no direct Go equivalent.

DataInput – Data can be read as a stream of binary encoded values. Some Go encoding libraries provide a similar function.

DataOutput – Data can be written as a stream of binary encoded values. Some Go encoding libraries provide a similar function.

Externalizable – Data can be read/written to a stream using non-standard encoding; no direct Go equivalent.

FileFilter – Select directory paths matching a filter callback; no direct Go equivalent.

FilenameFilter – Select file names matching a filter callback; no direct Go equivalent.

Flushable – Can flush (persist buffered data); some Go io package interfaces provide this operation.

ObjectInput – Can read Java serialized objects (superset of DataInput); no direct Go equivalent.

ObjectOutput – Can write Java serialized objects (superset of DataOutput); no direct Go equivalent.

Serializable – Declares a type as serializable by the default encoding; no direct Go equivalent.

Class Summary

BufferedInputStream – Input stream (on bytes) with buffer; the Go bufio package provides similar support.

BufferedOutputStream – Output stream (on bytes) with buffer; the Go bufio package provides similar support.

BufferedReader – Input writer (on characters) with buffer; the Go bufio package provides similar support.

BufferedWriter – Output writer (on characters) with buffer; the Go bufio package provides similar support.

ByteArrayInputStream – Read from byte[]; the Go io package provides similar support.

ByteArrayOutputStream – Write on byte[]; the Go io package provides similar support.

CharArrayReader – Write on char[]; the Go io package provides similar support.

CharArrayWriter – Write on char[]; the Go io package provides similar support.

Console – Abstraction of STDIN, STDOUT, and STDERR; the Go io package provides similar support.

DataInputStream – Read a stream of binary encoded values; some Go encoding libraries provide a similar function.

DataOutputStream – Write a stream of binary encoded values; some Go encoding libraries provide a similar function.

File – Access to a file (or directory); Go io and os packages provide similar support.

FileDescriptor – Access to host OS files; Go io and os packages provide similar support.

FileInputStream – Read bytes from a file; Go io and os packages provide similar support.

FileOutputStream – Write bytes to a file; Go io and os packages provide similar support.

FilePermission – Access file permissions; Go io and os packages provide similar support.

FileReader – Read characters from a file; Go io and os packages provide similar support.

FileWriter – Write characters to a file; Go io and os packages provide similar support.

InputStream – Read bytes; Go io and os packages provide similar support.

InputStreamReader – Convert byte input to character input; Go io and os packages provide similar support.

ObjectInputStream – Read serialized objects; no direct Go equivalent.

ObjectOutputStream – Write serialized objects; no direct Go equivalent.

OutputStream – Write bytes; Go io and os packages provide similar support.

OutputStreamWriter – Convert characters to bytes.

PrintStream – Formatted byte output; Go fmt, io, and os packages provide similar support.

PrintWriter – Formatted character output; Go fmt, io, and os packages provide similar support.

RandomAccessFile – A file that supports seeking; Go io and os packages provide similar support.

Reader – Read characters; Go fmt, io, and os packages provide similar support.

SequenceInputStream – Concatenate input streams; Go io and os packages provide similar support.

StreamTokenizer – Tokenize stream input; Go fmt, io, and os packages provide similar support.

StringReader – Read characters from a string; Go fmt, io, and os packages provide similar support.

Writer – Write characters; Go io and os packages provide similar support.

AttributedCharacterIterator – Bidirectional iteration over attributed text sequences; no direct Go equivalent.

CharacterIterator – Bidirectional iteration over text sequences; no direct Go equivalent; utf8 and utf16 packages have some function.

Annotation – Annotation-like text attributes.

AttributedString – String with annotations.

Bidi – Provides bidirectional traversal rules.

BreakIterator – Iterates to different types of breaks (word, line, etc.).

ChoiceFormat – Helps to format messages with varying counts and plurals.

CollationElementIterator – Walks across characters in under locale rules.

CollationKey – Key for locale-based collation.

Collator – Base class for locale-based collation.

CompactNumberFormat – Decimal format that makes numbers smaller.

DateFormat – Formats dates and times; Go has a time package for a similar function.

DecimalFormat – Formats decimal numbers.

Format – Base class for various Format classes.

MessageFormat – Formats messages with substitutions.

Normalizer – Normalizes Unicode text to assist with collation.

NumberFormat – Base class for number formatters.

RuleBasedCollator – Rules table driver collator.

SimpleDateFormat – Date format with configurable structures for dates and times; Go has a time package for a similar function.

StringCharacterIterator – Iterates over characters in a string.

ChronoLocalDate – A Date in some Chronology

ChronoLocalDateTime<D extends ChronoLocalDate> – A Date Time (timestamp) in some Chronology

Chronology – A calendar system (say Gregorian)

ChronoPeriod – A time period

ChronoZonedDateTime<D extends ChronoLocalDate>> – A time zoned Date Time (timestamp) in some Chronology

Era – A bounded range in some Chronology (e.g., BCE)

Temporal – Of Time; following for manipulating dates and times

TemporalAccessor

TemporalAdjuster

TemporalAmount

TemporalField

TemporalQuery<R>

TemporalUnit

Clock – Access to dates and times

Duration – A span of time; Go has a Duration type

Instant – A moment in time

LocalDate – A date in the local time zone

LocalDateTime – A date and time (aka timestamp) in the local time zone

LocalTime – A time in the local time zone

MonthDay – A day in a month

OffsetDateTime – A date and time (aka timestamp) offset from UTC

OffsetTime – A time offset from UTC

Period – A duration in calendar units

Year – A duration in years

YearMonth – An instant at month resolution

ZonedDateTime – A DateTime in a time zone

DateTimeFormatter – Formats a Date Time

DateTimeFormatterBuilder – Makes a formatter

AbstractChronology – Base for Chronologies (calendar system)

HijrahChronology, HijrahDate, IsoChronology

JapaneseChronology, JapaneseDate, JapaneseEra

MinguoChronology, MinguoDate

ThaiBuddhistChronology, ThaiBuddhistDate

Collection<E> – Iterate able collection of type E.

Comparator<T> – Compare two comparable objects of type T.

Deque<E> – Double-ended queue of type E; the Go slice is close.

Enumeration<E> – Supports forward iteration over a collection of type E.

EventListener – Formalize the type of an event listener (call back).

Formattable – Can be formatted.

Iterator<E> – Supports bidirectional iteration over a collection of type E.

List<E> – Indexable collection of type E; the Go slice is close.

Map<K,​V>, Map.Entry<K,​V> – Associative collection of type V with key K; the Go map is close.

Queue<E> – A queue (FIFO) of type E; the Go slice is close.

Set<E> – A set of type K; the Go map is close.

SortedMap<K,​V> – Map with sorted keys.

SortedSet<E> – Set with sorted elements.

AbstractCollection<E> – The following are base implementations of the type.

AbstractList<E>

AbstractMap<K,​V>

AbstractQueue<E>

AbstractSequentialList<E>

AbstractSet<E>

ArrayDeque<E> – Deque on an array.

ArrayList<E> – List on an array; Go has a slice type.

Arrays – Helpers for array access.

Base64.Decoder – Decode Base64 strings; Go has a base64 package.

Base64.Encoder – Encode Base64 strings; Go has a base64 package.

BitSet – Set of bits; Go has a bits package.

Calendar – A calendar; Go has a time package.

Collections – Helpers for collections.

Currency – A currency.

Date – A date; Go has a time package.

Dictionary<K,​V> – A basic map type; Go has a map type.

EnumMap<K extends Enum<K>,​V>

EnumSet<E extends Enum<E>>

EventListenerProxy<T extends EventListener>

EventObject

Formatter

GregorianCalendar – Western calendar.

HashMap<K,​V> – Default map type; Go has a map type.

HashSet<E> – Default set type.

Hashtable<K,​V> – Thread-safe HashMap.

IdentityHashMap<K,​V> – Map with Object identities as keys; Go has a map[uintptr] type.

LinkedHashMap<K,​V> – Map iterated in addition order.

LinkedHashSet<E> – Set iterated in addition order.

LinkedList<E> – List backed by a linked list.

Locale – Define locale-sensitive settings and behavior.

Objects – Helps for all reference types.

Optional<T> – A null-safe wrapper.

PriorityQueue<E> – List sorted by priority.

Properties – A key/value collection with a persistent form.

Scanner – Reads formatted input; Go fmt package.

SimpleTimeZone – A time zone implementation.

Stack<E> – List processed in LIFO order.

StringJoiner – String helper.

StringTokenizer – Simple string parser; Go fmt package.

Timer – Drive events (callbacks) at intervals.

TimerTask – Drive events (callbacks) at intervals.

TimeZone – Base for time zones.

TreeMap<K,​V> – Map sorted by keys.

TreeSet<E> – Set sorted by keys.

UUID – UUID type; available from third parties.

Vector<E> – Thread-safe ArrayList.

WeakHashMap<K,​V> – Map that does not prevent GC of keys.

Interface Summary

BlockingDeque<E> – Deque with multiple consumer threads.

BlockingQueue<E> – Queue with multiple consumer threads.

Callable<V> – A thread can call asynchronously.

ConcurrentMap<K,​V> – Thread-safe high concurrency map.

ConcurrentNavigableMap<K,​V> – Thread-safe high concurrency map.

Executor – Manager of multiple threads.

ExecutorService – Manages multiple threads.

Flow.Processor<T,​R> – Reactive programming flow processor.

Flow.Publisher<T> – Reactive programming flow publisher.

Flow.Subscriber<T> – Reactive programming flow subscriber.

Flow.Subscription – Reactive programming flow subscription.

Future<V> – Asynchronous task that can complete in the future.

Condition – Externalized Condition with lock; Go sync.Cond.

Lock – Lock access to critical section; Go sync.Mutex.

ReadWriteLock – Multiple read, single write Lock.

AbstractExecutorService

ArrayBlockingQueue<E>

CompletableFuture<T>

ConcurrentHashMap<K,​V>

ConcurrentLinkedDeque<E>

ConcurrentLinkedQueue<E>

ConcurrentSkipListMap<K,​V>

ConcurrentSkipListSet<E>

CopyOnWriteArrayList<E>

CopyOnWriteArraySet<E>

CountDownLatch – Wait for count; Go sync.WaitGroup is similar.

CyclicBarrier – Allows multiple threads to reach synchronization points.

DelayQueue<E extends Delayed> – Queue of Delayed (enable at certain time).

Exchanger<V> – Allows threads to swap items.

Executors – Creates managers of multiple threads.

ForkJoinPool – Divide and conquer in multiple threads.

Future<V> – Asynchronous task that can complete in the future.

LinkedBlockingDeque<E>

LinkedBlockingQueue<E>

LinkedTransferQueue<E>

Phaser – Thread synchronization; enhanced CyclicBarrier or CountDownLatch.

PriorityBlockingQueue<E>

ScheduledThreadPoolExecutor

Semaphore – Basic controlled access to critical sessions; Go has a lock package.

SynchronousQueue<E>

ThreadPoolExecutor

AtomicBoolean – Atomic allows safe read-modify-write cycles across threads; Go has an async package.

AtomicInteger – Go has an async package.

AtomicIntegerArray

AtomicIntegerFieldUpdater<T>

AtomicLong – Go has an async package.

AtomicLongArray

AtomicLongFieldUpdater<T>

AtomicMarkableReference<V>

AtomicReference<V> – Go has an async package.

AtomicReferenceArray<E>

AtomicReferenceFieldUpdater<T,​V>

AtomicStampedReference<V>

DoubleAccumulator – Accumulators/adders support safe read-modify-write cycles across threads.

DoubleAdder – Go has an async package.

LongAccumulator – Go has an async package.

LongAdder– Go has an async package.

LockSupport – Locking helpers.

ReentrantLock – Lock implementation.

ReentrantReadWriteLock