Java Technologies. Lecture N. Valdas Rapševičius. Vilnius University Faculty of Mathematics and Informatics

Transcription

1 Java Technologies Lecture N Valdas Rapševičius Vilnius University Faculty of Mathematics and Informatics Valdas Rapševičius. Java Technologies 1

2 Session Outline Meet Duke! Java Platform JCP, JSR Java versions SE 7 SE 8 SE 9 Course Overview Lectures Hands-on Evaluation References Hands-on setup and instructions Valdas Rapševičius. Java Technologies 2

3 Java, JDK Java is generic, imperative, object-oriented, reflective programming language Java Technology refers to a set of several computer software products and specifications from Sun Microsystems (which has since merged with Oracle Corporation, 2010), that together provide a system for developing application software and deploying it in a cross-platform computing environment. Always changing history JDK J2SE (since 1.2, JSR since 1.4) Java SE (since 6) Open Source? Sun announced in JavaOne 2006 that Java would become free and open source software Sun released the Java HotSpot virtual machine and compiler as free software under the GNU General Public License on November 13, 2006, with a promise that the rest of the JDK Sun released the source code of the Class library under GPL on May 8, 2007, except some limited parts that were licensed by Sun from 3rd parties who did not want their code to be released under a free software and open-source license. Sun's goal is to replace the parts that remain proprietary and closed-source with alternative implementations and make the class library completely free and open source. See Valdas Rapševičius. Java Technologies 3

4 Quiz 01 You and Java: 1. Know Java exists 2. + University course only 3. + Took part in at least one project 4. + First choice for any project 5. + Use it daily for studies/work Valdas Rapševičius. Java Technologies 4

5 Java Platform 1. Java 2, Standard Edition (J2SE) is designed for desktop computers. Most often it runs on top of OS X, Linux, Solaris, or Microsoft Windows 2. Java 2, Enterprise Edition (J2EE) is a comprehensive platform for multi-user, enterprise-wide applications. It is based on J2SE and adds APIs for server-side computing. 3. Java 2, Micro Edition (J2ME) is a set of technologies and specifications developed for small devices like pagers, mobile phones, and set-top boxes. J2ME uses subsets of J2SE components, such as smaller virtual machines and leaner APIs Valdas Rapševičius. Java Technologies 5

6 Java Platform Valdas Rapševičius. Java Technologies 6

7 Java SE Valdas Rapševičius. Java Technologies 7

8 Java Community Process (JCP) Specifications for J2SE, J2EE, and J2ME are developed under the Java Community Process (JCP) A specification begins with a Java Specification Request (JSR). An expert group consisting of representatives from interested companies is formed to create the specification The JSR then passes through various stages in the JCP before it is finished. Every JSR is assigned a number. See for everything Sandbox: Valdas Rapševičius. Java Technologies 8

9 Java SE 7 (since 2011) JVM support for dynamic languages Compressed 64-bit pointers Project Coin: Strings in switch Automatic resource management in try-statement Improved type inference for generic instance creation Simplified varargs method declaration Binary integer literals Allowing underscores in numeric literals Catching multiple exception types and re-throwing exceptions with improved type checking Concurrency utilities under JSR-166 New I/O Library-level support for Elliptic curve cryptography algorithms XRender pipeline for Java 2D (for modern GPUs) New platform APIs for the graphics features Enhanced libraries for new network protocols (SCTP and SDP) Upstream updates to XML and Unicode Valdas Rapševičius. Java Technologies 9

10 Java SE 8 (since 2014) New functionality JSR 308: Annotations on types JSR 310: Date and Time API JSR 335: Lambda expressions Updated functionality JSR 114: JDBC Rowsets JSR 160: JMX Remote API JSR 173: Streaming API for XML JSR 199: Java Compiler API JSR 206: Java API for XML Processing JSR 221: JDBC 4.0 JSR 269: Pluggable Annotation-Processing AP Valdas Rapševičius. Java Technologies 10

11 Java SE 9: What to expect? EA release from: Features Modular source code (Project Jigsaw) Lightweight JSON API HTTP 2 Client Process API updates Improved Lock Contention Java Shell (Read-Eval-Print Loop) Schedule 2017/02/09 All Tests Run 2017/02/16 Zero Bug Bounce 2017/03/16 Rampdown Phase /07/06 Final Release Candidate 2017/07/27 General Availability Valdas Rapševičius. Java Technologies 11

12 Quiz 02 Which Java version are you familiar with? 1. Java 6 2. Java 7 3. Java 8 4. Java 9 5. Groovy 6. Scala 7. None or idek Valdas Rapševičius. Java Technologies 12

13 Course Contents / Primary 1. Language basics 2. Essential classes and methods 3. Functional programming 4. Design patterns 5. JVM 6. Persistence Valdas Rapševičius. Java Technologies 13

14 Course Contents / Secondary 1. Development and configuration tools (Ant, Maven, Gradle) 2. GUI (AWT, Swing) 3. XML (Parsing, XSL, XSD) 4. Enterprise Application Servers (Managed Beans) 5. Networking (Sockets, RMI) 6. Web (Servlet, JSP) 7. Component Web (JSF, others) 8. Web services (SOAP, REST) 9. Polyglot programming primer (Groovy, Scala, Clojure) Valdas Rapševičius. Java Technologies 14

15 Course organization Lecture + demos (PBL?) Tuesdays, 16:00 17:30 Hands-on consultation Tuesdays, 18:00 19:30 Other consultation, questions valdas.rapsevicius@mif.vu.lt Baltupiai, room 325 (weekdays 10am to 3pm) VMA Announcements (+ ) Tasks, Instructions Evaluation Valdas Rapševičius. Java Technologies 15

16 Hands-on Tasks Task packages: Feb - Mar: environment setup, first hands-on project Mar - Apr: essential classes and methods Apr - May: persistence API, concurrency, networking All tasks must be submitted before the end of second month (1 package = 2 months) Instructions (see next slides, demo) Valdas Rapševičius. Java Technologies 16

17 Evaluation Tasks 1 task bundle = 2 points Max 6 points from hands-on tasks Exam allowed only if first 2 hands-on tasks completed! Plagiarism check before exam! Exam Score can be reduced or rejected! 1 exam task bundle No instructions 2 hours programming Max 4 points Valdas Rapševičius. Java Technologies 17

18 Results for years 2014, 2015, Valdas Rapševičius. Java Technologies 18

19 #1 Online Java SE Downloads Java SE Tutorial Java EE Tutorial Java SE API documentation Java EE API documentation The Java Virtual Machine Specification OpenJDK Valdas Rapševičius. Java Technologies 19

20 #1 Books Joshua Bloch. Effective Java (2nd Edition) Java 8 in Action. Lambdas, streams, and functional-style programming Benjamin J Evans, Martijn Verburg. The Well-Grounded Java Developer: Vital techniques of Java 7 and polyglot programming Charlie Hunt, Binu John. Java Performance Erich Gamma, et al. Design Patterns: Elements of Reusable Object-Oriented Software (Addison-Wesley Professional Computing Series) Mark Cade, Simon Roberts. Sun Certified Enterprise Architecture for J2EE Technology Study Guide Valdas Rapševičius. Java Technologies 20

21 Quiz 03 Are you familiar with? 1. Apache Ant 2. Apache Ivy 3. Apache Maven 4. Gradle From Valdas Rapševičius. Java Technologies 21

22 Hands-on: Setup Manual Install Java SE 1.8 JDK Git VCS Apache Maven Any editor, i.e. notepad, vim, Recommended Eclipse Install m2e plugin Netbeans IntelliJ Valdas Rapševičius. Java Technologies 22

23 Quiz 04 Which IDE will you use for the course (if any)? 1. Netbeans 2. Eclipse 3. IntelliJ 4. Vim (or other text editor) and CLI 5. Undecided Valdas Rapševičius. Java Technologies 23

24 Hands-on: Instructions Download package $ git co Options Console Change to unpacked dir $ cd tasks01 Build and test $ mvn test Create/edit code at $ vim src/main/java $ vim src/main/resources (optional) Test again until you get SUCCESS! IDE Open project in IDE, create/edit code, test project Once done pack code files and $ mvn package $ ls target/task sources.jar Checkout Compile tests Run tests Check code Package Submit code Valdas Rapševičius. Java Technologies 24

25 Maven project structure./pom.xml./src # Do not put your code here!./src/test./src/test/java./src/test/java/lt/mif/./src/test/resources # Put your code here!./src/main./src/main/java./src/main/java/lt/mif/./src/main/resources // Project configuration // Source code folder // Test files // Test Java files // Test Java packages, files // Other test files // Source code files // Source code Java files // Source Java packages, files // Other source files # This is temporary folder, removed by mvn clean./target // Build products./target/test-classes // Compiled test class files./target/classes // Compiled source class files./target/{project}-{version}-sources.jar // Source bundle to submit! Valdas Rapševičius. Java Technologies 25

26 Maven Project Lifecycle Valdas Rapševičius. Java Technologies 26

27 Maven cheat list Compile, run tests and checks $ mvn clean test Compile, run tests, checks and package $ mvn clean package Compile code only $ mvn compile Compile tests only $ mvn test-compile Compile, run checks only $ mvn -DskipTests test Package, skip checks and tests $ mvn -DskipTests -Dcheckstyle.skip=true package Compile, run single test file $mvn -Dtest=lt.vu.mif.jate.tasks.task01.StringUtilityTest test Remove all build products $ mvn clean Valdas Rapševičius. Java Technologies 27

28 JUnit Unit testing Unit testing with JUnit To write a test with Method to check the expected result of the code execution versus the actual result Use Eclipse, Netbeans or the org.junit.runner.junitcore class to run the test. Example: import org.junit.test; import static org.junit.assert.*; public class MyUnitTest { public void testconcatenate() { SomeClass c = new SomeClass(); String result = c.concatstrings("one", "two"); assertequals("onetwo", result); } Valdas Rapševičius. Java Technologies 28

29 JUnit: org.junit.assert static void static void static void static void static void static void static void static <T> void static void static void static void assertarrayequals(byte[] expecteds, byte[] actuals) Asserts that two byte arrays are equal. assertequals(java.lang.object expected, java.lang.object actual) Asserts that two objects are equal. assertfalse(boolean condition) Asserts that a condition is false. assertnotnull(java.lang.object object) Asserts that an object isn't null. assertnotsame(java.lang.object unexpected, java.lang.object actual) Asserts that two objects do not refer to the same object. assertnull(java.lang.object object) Asserts that an object is null. assertsame(java.lang.object expected, java.lang.object actual) Asserts that two objects refer to the same object. assertthat(java.lang.string reason, T actual, org.hamcrest.matcher<t> matcher) Asserts that actual satisfies the condition specified by matcher. asserttrue(boolean condition) Asserts that a condition is true. fail() Fails a test with no message. fail(java.lang.string message) Fails a test with the given message Valdas Rapševičius. Java Technologies 29

30 Session Conclusions Java language and technology is (still) a hype! Course content and pace depends on you Exam is tough get well prepared Do the tasks by yourself Use techniques from lecture Use practise hours for questions, exercises Valdas Rapševičius. Java Technologies 30