Preparación para la certificación Java SE 17 Developer

Understanding Java Technology and environment

• Describe Java Technology and the Java development 

• Identify key features of the Java language 

• Describe the Java Development Kit (JDK) and the Java Runtime Environment (JRE) 

• Describe the components of object-oriented programming 

• Describe the components of a basic Java program 

• Compile and execute a Java program 

Creating a Simple Java Program

• Create an executable Java program with a main class 

• Identify the conventions to be followed in a Java program 

• Use single-line and multi-line comments in Java programs 

• Use Java reserved words 

• Compile and run a Java program from the command line 

• Create and import packages 

• Import other Java packages to make them accessible in your code 

• Describe the java.lang package 

Java Platform Module System

• Describe the Modular JDK 

• Declare modules and enable access between modules 

• Describe how a modular project is compiled and run 

Migration to a Modular Application

• Migrate the application developed using a Java version prior to SE 9 to SE 11 

• Top-down and bottom-up migration 

• Splitting a Java SE 8 application into modules for migration 

• Use jdeps to determine dependencies and identify ways to address the cyclic dependencies 

Working with Java Data Types

• Declare and initialize variables including a variable using final 

• Cast a value from one data type to another including automatic and manual promotion 

• Declare and initialize a String variable 

Working with Java Operators

• Use basic arithmetic operators to manipulate data including +, -, *, /, and % 

• Use the increment and decrement operators 

• Use relational operators including ==, !=, >, >=, <, and <= 

• Use arithmetic assignment operators 

• Use conditional operators including &&, ||, and ? 

• Describe the operator precedence and use of parenthesis 

Using Decision Statements

• Use the decision making statement (if-then and if-then-else) 

• Use the switch statement 

• Compare how == differs between primitives and objects 

• Compare two String objects by using the compareTo and equals methods 

Using Looping Statements

• Describe looping statements 

• Use a for loop including an enhanced for loop 

• Use a while loop 

• Use a do-while loop 

• Compare and contrast the for, while, and do-while loops 

• Develop code that uses break and continue statements 

Arrays and ArrayLists

• Use a one-dimensional array 

• Create and manipulate an ArrayList 

• Traverse the elements of an ArrayList by using iterators and loops including the enhanced for loop 

• Compare an array and an ArrayList 

Describing and Using Objects and Classes

• Declare and instantiate Java objects 

• Explain object's lifecycles (including creation, dereferencing by reassignment, and garbage collection) 

• Define the structure of a Java class 

• Read or write to object fields 

Creating and Using Methods

• Create methods and constructors with arguments and return values 

• Create and invoke overloaded methods 

• Apply the static keyword to methods and fields 

Applying Encapsulation

• Apply access modifiers 

• Apply encapsulation principles to a class 

Reusing Implementations Through Inheritance

• Create and use subclasses and superclasses 

• Create and extend abstract classes 

• Enable polymorphism by overriding methods 

• Utilize polymorphism to cast and call methods, differentiating object type versus reference type 

• Distinguish overloading, overriding, and hiding 

Exception Handling and Assertions

• Describe the advantages of Exception handling and differentiate among checked, unchecked exceptions, and Errors 

• Create try-catch blocks and determine how exceptions alter program flow 

• Create and invoke a method that throws an exception 

• Use the try-with-resources construct 

• Create and use custom exception classes 

• Test invariants by using assertions 

Java Nested Classes and Enumerations

• Create and use inner, nested and anonymous classes 

• Create and use final classes 

• Create and use enumerations 

Java Interfaces

• Create and use interfaces with default methods 

• Create and use interfaces with private methods 

• Functional Interface and Lambda Expressions 

• Define and write functional interfaces 

• Create and use lambda expressions including statement lambdas, local-variable for lambda parameters 

Built-in Functional Interfaces

• Use interfaces from the java.util.function package 

• Use core functional interfaces including Predicate, Consumer, Function and Supplier 

• Use primitive and binary variations of base interfaces of java.util.function package 

Java Stream API

• Describe the Stream interface and pipelines 

• Use lambda expressions and method references 

Lambda Operations on Streams

• Extract stream data using map, peek and flatMap methods 

• Search stream data using search findFirst, findAny, anyMatch, allMatch and noneMatch methods 

• Use the Optional class 

• Perform calculations using count, max, min, average and sum stream operations 

• Sort a collection using lambda expressions 

• Use Collectors with streams, including the groupingBy and partitioningBy operations 

Parallel Streams

• Develop code that uses parallel streams 

• Implement decomposition and reduction with streams 

Java Collections Framework and Generics

• Use wrapper classes, autoboxing and autounboxing 

• Create and use generic classes, methods with diamond notation and wildcards 

• Describe the Collections Framework and use key collection interfaces 

• Use Comparator and Comparable interfaces 

• Create and use convenience methods for collections 

Java I/O API (Fundamentals and NIO2)

• Read data from and write console and file data using I/O Streams 

• Use I/O Streams to read and write files 

• Read and write objects by using serialization 

• Use the Path interface to operate on file and directory paths 

• Use the Files class to check, delete, copy or move a file or directory 

• Use the Stream API with Files 

Database Applications with JDBC

• Connect to databases using JDBC URLs and DriverManager 

• Use PreparedStatement to perform CRUD operations 

• Use PreparedStatement and CallableStatement APIs to perform database operations 

Java Annotations

• Describe the purpose of annotations and typical usage patterns 

• Apply annotations to classes and methods 

• Describe commonly used annotations in the JDK 

• Declare custom annotations 

Localization in Java

• Use the Locale class 

• Use resource bundles 

• Format messages, dates, and numbers with Java 

Java Concurrency and Multithreading

• Create worker threads using Runnable, Callable and use an ExecutorService to concurrently execute tasks 

• Use java.util.concurrent collections and classes including CyclicBarrier and CopyOnWriteArrayList 

• Write thread-safe code 

• Identify threading problems such as deadlocks and livelocks