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Java Tutorials and Best Practices

Category: Java core

How to zip file in java

Java core

How to create a zip file in Java

In this tutorial, we show how to create a zip file from multiple files in Java. 1- ByteArrayOutputStream & ZipOutputStream Using ByteArrayOutputStream and ZipOutputStream classes provided by the JDK, you...

How to read a plain text file in Java

Java core

How to read a plain text file in Java

This tutorial shows several ways for reading plain text files in Java. The techniques we use here are totally JDK built-in and don’t depend on external libraries. 1- BufferedReader The...

How to read input from console in Java

Java core

How to read input from console in Java

This tutorial shows several ways for reading input from a console in Java. Before listing the ways, it’s worth to define System.in as it’s used by most reading ways. System.in...

How to modify XML using DOM in Java

Java core

How to modify XML using DOM in Java

Although the main purpose of XML documents is to store lightweight data for faster processing, they are still used in some small applications as a data store which requires dynamic...

How to read XML using STAX parser

Java core

How to read XML using STAX parser

STAX is yet another parser for reading and parsing XML documents in Java, it is very similar to SAX where they both parse the XML document on call and provide...

How to read XML using SAX parser

Java core

How to read XML using SAX parser

In the previous article we talked about DOM parser and provided different examples for parsing and reading elements of an XML document. SAX parser is yet another XML parser provided...

How to create XML file in Java

Java core

How to create XML file in Java

In this tutorial, we show how to create a new XML file using DOM parser provided by JDK. We’re going to create an XML called students.xml which lists students along...

How to read XML file in Java

Java core

How to read XML file in Java

In this tutorial, we show how to read and parse an XML file using DOM parser provided by JDK. If you’re interested in SAX or STAX parser, please refer to these tutorials: SAX parser, STAX...

ClassNotFoundException vs NoClassDefFoundError

Java core

ClassNotFoundException vs NoClassDefFoundError

ClassNotFoundException and NoClassDefFoundError occur when a required class is not found in the classpath at runtime. In this tutorial, we resolve the conflict between these 2 exceptions and explain the different...

How to iterate a Map in Java

Java core

How to iterate a Map in Java

This tutorial shows several ways for iterating a Map in Java. 1- Entry Set The common way for iterating a Map in Java is through entrySet() method as the following:...

How to iterate a List in Java

Java core

How to iterate a List in Java

This tutorial shows several ways for iterating a List in Java. 1- Typical For loop Using a typical For loop, you can iterate a List as the following:

2-...

ArrayList vs Vector

Java core

ArrayList vs Vector

ArrayList and Vector collections are used interchangeably for storing several items with the same type inside the memory. In this tutorial, we list the major similarities and differences between these 2...

Hashtable VS HashMap

Java core

Hashtable VS HashMap

Hashing objects like HashMap and Hashtable are mostly used for storing and caching data as a key/value pairs inside the memory. In this tutorial, we list the major similarities and...

Java – Convert File to byte[]

Java core

Java – Convert File to byte[]

This tutorial shows several ways to convert a File object to a byte[] array in Java. 1- Traditional way The traditional conversion way is through using read() method of InputStream as...

Java – Convert byte[] to File

Java core

Java – Convert byte[] to File

This tutorial shows several ways to convert a byte[] array to File in Java. 1- Traditional way The traditional way of doing the conversion is through using FileOutputStream as the...

Convert JSON to Java Object

Java core

Convert JSON to Java Object

This tutorials shows 2 ways for converting a JSON string to a Java object. 1- Gson Gson is the most popular library for converting JSON string to Java objects. With Gson, you...