Java.io Package in Java Last Updated : 23 Jul, 2025 Suggest changes Share Like Article Like Report Java.io Package in JavaThis package provides for system input and output through data streams, serialization and the file system. Unless otherwise noted, passing a null argument to a constructor or method in any class or interface in this package will cause a NullPointerException to be thrown. Following are the important classes in Java.io package: BufferedInputStreamBufferedOutputStreamBufferedReaderBufferedWriterByteArrayInputStreamByteArrayOutputStreamCharArrayReaderCharArrayWriter – Set1 Set2ConsoleDataInputStream – Set1 Set2DataOutputStreamFileFileDescriptorFileInputStreamFileOutputStreamFilePermissionFileReader and FileWriterFilterInputStreamFilterOutputStreamFilterReaderFilterWriterInputStreamInputStreamReaderLineNumberInputStreamLineNumberReaderObjectInputStream – Set1 Set2ObjectInputStream.GetFieldObjectOutputStream – Set 1 Set2ObjectOutputStream.PutFieldObjectStreamClassObjectStreamFieldOutputStreamOutputStreamWriterPipedInputStreamPipedOutputStreamPipedReaderPipedWriterPrintStream – Set1 Set2PrintWriter – Set1 Set2PushbackInputStreamPushbackReaderRandomAccessFile- Set1 Set2 Set3ReaderSequenceInputStreamSerializablePermissionStreamTokenizer – Set1 Set2StringBufferInputStreamStringReaderStringWriterWriterZipInputStream class in JavaZipEntry class in JavaJarEntry class in JavaZipOutputStream class in JavaZip.InflaterInputStream class in JavaZip.DeflaterInputStream class in JavaZip.DeflaterOutputStream class in Java K kartik Follow 0 Article Tags : Java Java-I/O Java-Packages Explore Java BasicsIntroduction to Java3 min readJava Programming Basics9 min readJava Methods6 min readAccess Modifiers in Java4 min readArrays in Java7 min readJava Strings8 min readRegular Expressions in Java3 min readOOP & InterfacesClasses and Objects in Java9 min readAccess Modifiers in Java4 min readJava Constructors4 min readJava OOP(Object Oriented Programming) Concepts10 min readJava Packages7 min readJava Interface7 min readCollectionsCollections in Java12 min readCollections Class in Java13 min readCollection Interface in Java4 min readIterator in Java5 min readJava Comparator Interface6 min readException HandlingJava Exception Handling6 min readJava Try Catch Block4 min readJava final, finally and finalize4 min readChained Exceptions in Java3 min readNull Pointer Exception in Java5 min readException Handling with Method Overriding in Java4 min readJava AdvancedJava Multithreading Tutorial3 min readSynchronization in Java10 min readFile Handling in Java4 min readJava Method References9 min readJava 8 Stream Tutorial7 min readJava Networking6 min readJDBC Tutorial5 min readJava Memory Management4 min readGarbage Collection in Java6 min readMemory Leaks in Java3 min readPractice JavaJava Interview Questions and Answers15+ min readJava Programs - Java Programming Examples7 min readJava Exercises - Basic to Advanced Java Practice Programs with Solutions5 min readJava Quiz1 min readJava Project Ideas For Beginners and Advanced15+ min read My Profile ${profileImgHtml} My Profile Edit Profile My Courses Join Community Transactions Logout Like