Recently, more and more people are looking on the Internet for information on how to edit PDF files and whether it is possible to do it at all.
The fact is that very often a situation arises when a person downloads a file with some text and does not see that it is in the format.
He needs to edit the text inside this file or take a part of it. But it is impossible to do this in conventional programs that allow you to simply view PDF.
Yes, some editors, such as those, suggest the ability to simply copy a test from PDF files by pressing the Ctrl + C and Ctrl + V key combinations, but when you paste information into a full-fledged one, it is greatly distorted.
There is a way out of this situation, and not even one.
As for what program can edit PDF files, the most popular of them are FineReader and the same Microsoft Word.
FineReader
Microsoft Word
Surprisingly, Microsoft Word 2013 and 2016 allow you to open PDF documents without any manual conversions - everything happens automatically!
You can get new versions of the most famous text editor on the official Microsoft website - https://products.office.com/ru-ru/home?WT.mc_id=oan_winnav_office.
This option allows you to purchase a licensed version.
But even without this, on the Internet, you can find a huge number of pirated versions with the same functionality.
In any case, to edit a document that is in PDF format, you need to do the following:
- Click the "File" button in the top menu.
- Select the "Open" command in the drop-down menu (highlighted in a red frame in Figure 8). After that, using the "Browse" button (highlighted in green), select the desired file in PDF format.
- After that, the program will display a message stating that it will slightly change the content of the document. This implies that the recognized document may not fully match the original.
But we have no choice, so we press the "OK" button, wait a little and get a finished document, ready for editing.
Online
In fact, you don't need to download or even buy any special software to convert PDF to Word.
Even with a simple Google search, you can find dozens of such sites.
At the same time, the algorithm for using such services is always the same and consists in simply downloading the desired file and pressing one button.
For example, consider the interface of the first service in the above list pdf2doc.com.
After we have followed the corresponding link, it is necessary to select the direction of conversion.
In this case, we will select "PDF to Doc", which, in fact, we were looking for (highlighted in red in Figure 10).
As expected, there is a corresponding button for uploading files, which is highlighted in blue in the same image.
The conversion is very fast and the converted file appears immediately in the list. We just have to click the "Download" button (highlighted in red in Figure 13).
It is done!
Another non-standard way to convert from PDF to Word can be seen in the video below.
How to Convert PDF to Word Document (No Programs)
Video tutorial on how to convert document from PDF to Word.
Key point: Java program is executed from the main method in the class.
Let's start with a simple Java program that displays the message “ Welcome to Java!". (The word "console" is an old computer term that refers to a device for inputting and displaying text on a computer. Console input means receiving input from the keyboard, and console output means displaying output on a monitor. In NetBeans, output is shown in a special window:
Outside of the IDE, console programs (i.e. without a graphical interface) are run on the command line. About the command line in the next section "".
Source code of the program
Public class Welcome (public static void main (String args) (// Show the message Welcome to Java! System.out.println ("Welcome to Java!");))
Line 1 defines the class. Every Java program must have at least one class. Each class has a name. It is assumed that class names begin with a capital letter. In this example, the class is named Welcome.
Line 2 defines the method main... The program starts execution from the method main... Method main is the entry point where the program starts execution.
A method is a construct that contains instructions. Method main in this program contains instructions System.out.println... The instruction displays the line “ Welcome to Java!». String is a programming term for a sequence of characters. The string must be enclosed in double quotes. Every instruction in Java ends with a semicolon ( ; ), which serves statement separator.
Reserved words, or as they are also called keywords, have a definite meaning to the compiler, and they cannot be used for other purposes in a program. For example, when the compiler sees the word class, he realizes that the word after class is the name of the class. Other reserved words in this program are public, static and void.
Line 3 is a comment, which documents the actions of the program and its structure. Comments help programmers communicate and understand the program. They are not programming instructions and are thus ignored by the compiler. In Java, comments are preceded by two slashes on the line ( // ), which is called - comment line... Comments can be placed between /* and */ on one or more lines, these lines are called block of comments or paragraph of comments... When the compiler sees // , then on this line it ignores all the text after // ... When he sees /* , it scans the next */ and ignores any text between /* and */ .
Some examples of comments:
// This program shows Welcome to Java! / * This program shows Welcome to Java! * / / * This program shows Welcome to Java! * /
A pair of curly braces in a program forms block, which groups the components of a program. In Java, every block starts with an opening curly brace ( {) and ends with a closing curly brace. ( } ). Each class has class block which groups the data and methods of a class. Similarly, each method has method block which groups instructions in a method. Blocks can be nested, this means that one block can be placed inside another, as shown in the following code:
Prompt: any opening curly brace must match a closing one. Whenever you type an opening curly brace, immediately type the closing curly brace to prevent errors caused by missing braces. Most Java IDEs automatically insert a closing curly brace for each opening.
Attention: Java source code is case sensitive. It would be wrong, for example, to replace in the program main on Main.
You are familiar with several special characters in the program (for example, { } , // , ; ). They are used in almost every program. The table summarizes their use:
| Symbol | Name | Description |
|---|---|---|
| {} | Opening and closing curly brace | Indicates a block for enclosing instructions. |
| () | Opening and closing parenthesis | Used with methods. |
| Opening and closing square brackets | Designates an array. | |
| // | Double slash | Preceded by a comment. |
| " " | Opening and closing quotes | Surrounds a string (i.e. a sequence of characters). |
| ; | Semicolon | Indicates the end of an instruction. |
The most common mistakes you will make while learning to program are syntax errors. Like any programming language, Java has its own syntax, and you need to write code that follows the syntax rules. If your program breaks a rule, such as missing a semicolon, missing curly brace, missing quote, or misspelled word, the Java compiler will report syntax errors.
Note: you might be wondering why the method main this is how it is defined and why is used to display the message in the console System.out.println (...)... For now, just take it for granted. In the chapters that follow, all your questions will be answered.
The program prints one message at the beginning. Now that you have a grasp of the program, it is easy to distribute it to display more messages. For example, you can rewrite your program to display three messages:
Public class WelcomeWithThreeMessages (public static void main (String args) (System.out.println ("Coding is fun!"); System.out.println ("Basics first"); System.out.println ("Problem Driven"); ))
As you know, Java is one of the most popular programming languages in the world and knowledge of it will significantly increase your importance as a programmer. So you've decided to start writing in this language. You will need to install the JDK in order to write and run Java programs. JDK is a set of software developed by Oracle that contains a compiler (javac), a runtime environment (Java Runtime Environment), a standard language library, examples and documentation. After reading this article, you will learn how to install and configure the JDK on your system, what a development environment is, and what IDEs exist for Java. Also you will write your first Java program.
Installing the Java Development Kit
- Go to the Oracle website and download the JDK for your platform.
- Once downloaded, extract the resulting archive and run the extracted application.
- During the installation process, select the "Development Tool" option and click "Next".
- After a while, the installation will complete.
So you've installed the Java Development Kit, but that's not all. You need to configure it for your system.
JDK setup using Windows example
- Go to the folder% ProgramFiles% \ Java \% version of the jdk% \ bin you installed, click on the properties of any file in this folder and copy the path to it.
- Go to the properties of your computer, open the "Advanced" tab, click "Environment Variables ...". In the window that opens, create a new variable, name it Path, paste the previously copied path into its value.
- Now comes the most important thing. Open a command prompt and type javac to make sure the JRE is installed and configured. If you get a list of arguments to the javac command, then congratulations, you have successfully installed and configured everything you need to use Java!
After installing the JDK and JRE, it doesn't hurt to install one of the IDEs on your computer.
Installing the IDE
First, let's figure out what it is IDE.
IDE(Integrated Development Environment) is a set of software tools used by programmers to develop software. The IDE makes it easy to write, run, debug, and test your code.
For writing complex programs, it is advisable to use an IDE. We will look at the most popular ones.
Notebook
Yes, and you can write code in notepad! For development, you just need to install the JDK and specify the path to it. Write the code in notepad, compile using the command line. However, for developing complex programs, this is not the best option due to the lack of any additional features present in advanced IDEs.
NetBeans
NetBeans is the choice of professional Java developers. It has unique features and tools that will allow you to make your program cross-platform and your code readable. NetBeans supports not only Java, but other programming languages for desktop and web development as well. It is completely free, you can download it from the official website. Here are just some of its features:
- code formatting;
- installation of third-party libraries;
- simple graphical interface;
- and many many others…
Eclipse
Eclipse, like Netbeans, is one of the more popular IDEs. It provides an impressive, intuitive interface and a powerful development environment that allows you to comfortably develop Java applications. You can download Eclipse for free from the official site. Advantages:
- the ability to format the code the way you like;
- support for splitting code into modules;
- ease of use of the same code in different projects;
- drag and drop;
- viewing the contents of libraries;
- user-friendly interface.
IntelliJ IDEA
IntelliJ IDEA is a well-known IDE for Java, written, oddly enough, in Java. Equipped with unique tools and allows you to navigate the program without any problems. Finding errors and debugging code has never been easier with IntelliJ IDEA.
JCreator
JCreator is the most advanced and fastest Java IDE written in C ++.
Writing our first program
So, you have installed and configured the JDK, JRE and IDE for Java. What's the next step? Of course, write a program to make sure everything works and you're ready to learn the language. You will become familiar with the basic structure of Java code and create your first program! It is worth noting that before learning Java, you should familiarize yourself with at least the simplest principles of object-oriented programming.
The structure of a Java program can be represented as follows:
Java program structure
The source code file contains several classes - these are parts of the program that have certain functions. It is good practice to split your program into multiple source files, each with a different purpose. Classes contain methods - actions that objects of a given class can perform. The method contains commands with which you can get the desired result.
Before you start creating a program, you need to create a project, and in it a file that will contain your code. Let's consider creating a project in the Eclipse IDE, but the process is not very different in other IDEs. Select "File" at the top, then hover over "New", in the menu that opens, select "Java Project". In the window that appears, enter the name of the project and other settings you need (if you are not sure what to do, then you can just leave everything as it is) and click "Next". Done, you have created a project! All that remains is to create a class in it, in which you will write your first program. Right click on your project (it should appear on the right) and choose New → Class. Give the new class a name (first in this example) and click Finish.
Let's start writing your first program. Traditionally, this is a program that displays "Hello, world!"
Public class first (public static void main (String args) (System.out.println ("Hello, world!");))
Let us analyze in parts what we have written:
- public is an access modifier that determines from which part of the program our class can be used. In your example, public is all the code;
- class is a keyword indicating that you are declaring a class and not anything else;
- first is the name of your class. Parentheses define the beginning and end of the class code;
- public static void main (String args) - declaration of a public static method (that is, which can be called without creating a class object). The method in the example does not return anything and takes an array of strings as arguments. The only command in this method prints the message "Hello, world!" To the console. Note, instead of println, you can write print, the only difference is that in the case of println, an additional line feed character will be displayed.
Okay, you've written your first program. Now you need to start it. To do this, just click the white arrow in the green circle on the top panel (when you hover over it, “Run” should be highlighted). After clicking, the console will open at the bottom, in which you will see the message “Hello, world”! Congratulations, you've written your first Java program and are ready to dive into the fascinating world of Java!
There are many in Java, and sometimes it is difficult to decide on their choice. It also happens that a user downloads a program that does not support the required programming language, after which he has to look for another. In this article, we will present a number of working programs, as well as select tutorials for Java programming. Of course, we will not be able to present all the programs, because there are quite a few of them. However, you can still see the most popular and interesting ones here.
Programs: Java programming language
In this list, we will present several programs to help you deal with this situation.
A powerful working environment for creating cross-platform programs in Java and other popular languages. It is free, the big plus is that it is compatible with Linux.
IntelliJ IDEA
The freeware program created by JetBrains has 2 versions for different types of development:
Ultimate - serves to develop web applications and programming for the phone, as well as software for the enterprise. It is paid but has a free trial period.
Community- created for programming in Java, Groovy, Scala, as well as for Android applications. We need to download it. To do this, just take a few simple steps:
- Let's go to the official JetBrains website.
- Let's go to the Tools section.
- We choose the IntelliJ IDEA program.
- Click the Download button.
- We download the program for our operating system.
Java Programming Tutorials
There are many programs and games for teaching programming languages, some of which we will now consider.
Let's start, perhaps, with the most interesting for the majority, namely: games for learning programming languages.
CodinGame
An excellent site where you have to write your own artificial intelligence using any programming languages. You have to solve interesting and funny puzzles, along the way you will learn.
Code hunt
In this game, you are a code hunter. Supports only 2 languages - Java and C #. In the game you have to go through 14 levels, each of which has its own tasks.
A popular platform for younger ages and students, with which you can compete with your friends to write code in some programming languages such as Java, CoffeeScript, JavaScript, Lua, Python. Clans and even the plot, interaction with players - all this will draw you into an exciting learning.
Robocode
From the name of the game, it is clear that in it you will have to create your own robots in the Java language, and then release your creations onto the battlefield.
Codewars
If you do not want to create robots, but compete with friends, solving real problems, then this game is undoubtedly for you.
Resources for learning Java
There are also sites where you can learn programming languages for free and solve problems there. Several sites will now be discussed.
Coursera
On this resource you will find many courses on programming languages, there is Russian localization. The site is free, however there is additional content that you have to pay for. So, for example, you can view material from the world's leading universities for free and complete practical assignments that do not require third-party verification. But if the work will be checked by other people or a teacher, then you will have to fork out from $ 49 (3200 rubles) per month.
A resource similar to Coursera (with the same fee), however, 49 $ (3200 rubles) you are not charged for checking assignments, but for obtaining a certificate for completing courses. And the rest of the materials will be available to you free of charge.
"Intuit"
This time, this is a domestic site where you can take courses for free or from 500 rubles per month for the services of a tutor and get good knowledge that can help you in life. If you want to study for free, you can do it yourself, and if you want to have a personal tutor, you will have to fork out for a small amount.
Let's summarize
There are many more sites, programs, or games that can help you learn to program or can be used as a work environment. But it is not at all necessary to describe and know all programs for programming in Java, it is enough just to choose for yourself one single one, to which you get used to and where it will be convenient for you to develop or learn. In the end, the choice is yours.
Having established 7 nominations, we will subjectively determine the best of the best:
Best Free IDE: NetBeans
NetBeans is the most powerful open source development environment for web, mobile and desktop applications. Works with Linux, Windows, MacOS and even Oracle Solaris.
Despite the fact that NetBeans allows you to work in multiple languages, it is considered Java-centric in the development environment. It interoperates nicely with JPA, JSP, Struts, Spring and the Hibernate library.
Best Commercial IDE: IntelliJ IDEA
In truth, IntelliJ IDEA comes in two versions, one of which is completely free - the Free Community Edition. Moreover, for a novice developer, this package is enough with his head. In particular, the Android Studio IDE, which will be discussed a little later, is based on this version.
In the paid version, you get support for Spring frameworks (Spring MVC framework, Spring Security, Spring Boot, Spring Integration, etc.), Node.js, Angular React, Grails, the ability to use additional languages (javascript, typescript, coffeescript) and interact with nearly seven popular servers (Tomcat, TomEE, GlassFish, JBoss, WildFly, Weblogic, WebSphere, Geronimo, Virgo, etc.).
Most Popular IDE: Eclipse
It is almost impossible to give an exact figure, but almost any Java developer with more than 2 years of experience has come across this IDE. Eclipse has become the winner of this nomination thanks to its large community, tons of useful information and countless numbers of plugins. As with its predecessors, Eclipse supports multiple languages, but is perceived to be Java-driven.
Most versatile IDE: JDeveloper
Another product from Oracle with a lot of advantages, including support for the version control system and the Oracle cloud service, it is packed with SQL Developer, PL / SQL query processor, WebLogic Server, HTML, CSS, JavaScript, JSF, JSP, WSDL editors and a huge amount all kinds of usefulness.
Best for Android: Android Studio
It would be strange if some other IDE became the winner in this category. In addition to all the possibilities that the original IntelliJ IDEA IDE gives you, Android Studio includes many add-ons from Google, both purely visual (layouts, formats, GPU profiler) and functional (JUnit 4 and Firebase Test Lab for testing and debugging, system builds Gradle, Instant Run).
Best IDE for Learning: DrJava
This is precisely the conclusion reached by a development team called JavaPLT representing Rice University. This is not surprising, considering that DrJava is their brainchild. However, leaving jokes aside, we have to admit that DrJava is really perfect for beginners, because this IDE does not even aim to compete with the above. Its main advantage is extremely fast setup and transition to direct code writing. Consider BlueJ, JGrasp and Greenfoot as competitors on similar terms.
Most Promising IDE: MyEclipse
The welcome caption on the download page reads “The best Java EE IDE enhanced for the full stack developer”. Well, this is very immodest, not at all supported by facts, but in truth, not far from the truth. In essence, MyEclipse is Eclipse, where everything is initially “screwed on”, “finished” and expanded a little more. The developer is offered several versions, two main ones - standard and professional. Standard is just Eclipse in a new shell, and Professional contains a mobile web simulator, an image editor, a UML editor, templates, add-ons - in general, everything that will make creating a product much easier.
What do you use?
