Java 8 Features

 

Java 8 Features

Oracle released a new version of Java as Java 8 in March 18, 2014. It was a revolutionary release of the Java for software development platform. It includes various upgrades to the Java programming, JVM, Tools and libraries.

Java 8 Programming Language Enhancements

Java 8 provides following features for Java Programming:

  • Lambda expressions,
  • Method references,
  • Functional interfaces,
  • Stream API,
  • Default methods,
  • Base64 Encode Decode,
  • Static methods in interface,
  • Optional class,
  • Collectors class,
  • ForEach() method,
  • Nashorn JavaScript Engine,
  • Parallel Array Sorting,
  • Type and Repating Annotations,
  • IO Enhancements,
  • Concurrency Enhancements,
  • JDBC Enhancements etc.

Lambda Expressions

Lambda expression helps us to write our code in functional style. It provides a clear and concise way to implement SAM interface(Single Abstract Method) by using an expression. It is very useful in collection library in which it helps to iterate, filter and extract data.


Method References

Java 8 Method reference is used to refer method of functional interface . It is compact and easy form of lambda expression. Each time when you are using lambda expression to just referring a method, you can replace your lambda expression with method reference.

Functional Interface

An Interface that contains only one abstract method is known as functional interface. It can have any number of default and static methods. It can also declare methods of object class.

Functional interfaces are also known as Single Abstract Method Interfaces (SAM Interfaces).

Optional

Java introduced a new class Optional in Java 8. It is a public final class which is used to deal with NullPointerException in Java application. We must import java.util package to use this class. It provides methods to check the presence of value for particular variable.

forEach

Java provides a new method forEach() to iterate the elements. It is defined in Iterable and Stream interfaces.

It is a default method defined in the Iterable interface. Collection classes which extends Iterable interface can use forEach() method to iterate elements.

This method takes a single parameter which is a functional interface. So, you can pass lambda expression as an argument.

Date/Time API

Java has introduced a new Date and Time API since Java 8. The java.time package contains Java 8 Date and Time classes.


Default Methods

Java provides a facility to create default methods inside the interface. Methods which are defined inside the interface and tagged with default keyword are known as default methods. These methods are non-abstract methods and can have method body.

Nashorn JavaScript Engine

Nashorn is a JavaScript engine. It is used to execute JavaScript code dynamically at JVM (Java Virtual Machine). Java provides a command-line tool jjs which is used to execute JavaScript code.

You can execute JavaScript code by two ways:

  1. Using jjs command-line tool, and
  2. By embedding into Java source code.

StringJoiner

Java added a new final class StringJoiner in java.util package. It is used to construct a sequence of characters separated by a delimiter. Now, you can create string by passing delimiters like comma(,), hyphen(-) etc.

Collectors

Collectors is a final class that extends Object class. It provides reduction operations, such as accumulating elements into collections, summarizing elements according to various criteria etc.

Stream API

Java 8 java.util.stream package consists of classes, interfaces and an enum to allow functional-style operations on the elements. It performs lazy computation. So, it executes only when it requires.

Stream Filter

Java stream provides a method filter() to filter stream elements on the basis of given predicate. Suppose, you want to get only even elements of your list, you can do this easily with the help of filter() method.


Java Base64 Encoding and Decoding

Java provides a class Base64 to deal with encryption and decryption. You need to import java.util.Base64 class in your source file to use its methods.

This class provides three different encoders and decoders to encrypt information at each level.

Java Parallel Array Sorting

Java provides a new additional feature in Arrays class which is used to sort array elements parallelly. The parallelSort() method has added to java.util.Arrays class that uses the JSR 166 Fork/Join parallelism common pool to provide sorting of arrays. It is an overloaded method.

Java 8 Security Enhancements

1) The Java Secure Socket Extension(JSSE) provider enables the protocols Transport Layer Security (TLS) 1.1 and TLS 1.2 by default on the client side.

2) A improved method AccessController.doPrivileged has been added which enables code to assert a subset of its privileges, without preventing the full traversal of the stack to check for other permissions.

3) Advanced Encryption Standard (AES) and Password-Based Encryption (PBE) algorithms, such as PBEWithSHA256AndAES_128 and PBEWithSHA512AndAES_256 has been added to the SunJCE provider.

4) Java Secure Socket Extension (SunJSSE) has enabled Server Name Indication (SNI) extension for client applications by default in JDK 7 and JDK 8 supports the SNI extension for server applications. The SNI extension is a feature that extends the SSL/TLS protocols to indicate what server name the client is attempting to connect to during handshaking.

5) The SunJSSE is enhanced to support Authenticated Encryption with Associated Data (AEAD) algorithms. The Java Cryptography Extension (SunJCE) provider is enhanced to support AES/GCM/NoPadding cipher implementation as well as Galois/Counter Mode (GCM) algorithm parameters.

6) A new command flag -importpassword is added to the keytool utility. It is used to accept a password and store it securely as a secret key. Classes such as java.security.DomainLoadStoreParameter andjava.security.PKCS12Attribute is added to support DKS keystore type.

7) In JDK 8, the cryptographic algorithms have been enhanced with the SHA-224 variant of the SHA-2 family of message-digest implementations.

8) Enhanced support for NSA Suite B Cryptography which includes:

  • OID registration for NSA Suite B cryptography algorithms
  • Support for 2048-bit DSA key pair generation and additional signature algorithms for 2048-bit DSA keys such as SHA224withDSA and SHA256withDSA.
  • Lifting of the keysize restriction from 1024 to 2048 for Diffie-Hellman (DH) algorithm.

9) SecureRandom class provides the generation of cryptographically strong random numbers which is used for private or public keys, ciphers and signed messages. The getInstanceStrong() method was introduced in JDK 8, which returns an instance of the strongest SecureRandom. It should be used when you need to create RSA private and public key. SecureRandom includes following other changes:

  • Two new implementations has introduced for UNIX platforms, which provide blocking and non-blocking behavior.

10) A new PKIXRevocationChecker class is included which checks the revocation status of certificates with the PKIX algorithm. It supports best effort checking, end-entity certificate checking, and mechanism-specific options.

11) The Public Key Cryptography Standards 11 (PKCS) has been expanded to include 64-bit supports for Windows.

12) Two new rcache types are added to Kerberos 5. Type none means no rcache at all, and type dfl means the DFL style file-based rcache. Also, the acceptor requested subkey is now supported. They are configured using the sun.security.krb5.rcache and sun.security.krb5.acceptor.subkey system properties.

13) In JDK 8, Kerberos 5 protocol transition and constrained delegation are supported within the same realm.

14) Java 8 has disabled weak encryption by default. The DES-related Kerberos 5 encryption types are not supported by default. These encryption types can be enabled by adding allow_weak_crypto=true in the krb5.conf file.

15) You can set server name to null to denote an unbound server. It means a client can request for the service using any server name. After a context is established, the server can retrieve the name as a negotiated property with the key name SASL.BOUND_SERVER_NAME.

16) Java Native Interface (JNI) bridge to native Java Generic Security Service (JGSS) is now supported on Mac OS X. You can set system property sun.security.jgss.native to true to enable it.

17) A new system property, jdk.tls.ephemeralDHKeySize is defined to customize the ephemeral DH key sizes. The minimum acceptable DH key size is 1024 bits, except for exportable cipher suites or legacy mode (jdk.tls.ephemeralDHKeySize=legacy).

18) Java Secure Socket Extension (JSSE) provider honors the client's cipher suite preference by default. However, the behavior can be changed to respect the server's cipher suite preference by calling SSLParameters.setUseCipherSuitesOrder(true) over the server.

Java 8 Tools Enhancements

1) A jjs command is introduced, which invokes the Nashorn engine either in interactive shell mode, or to interpret script files.

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