Home - Yash-777/LearnJava GitHub Wiki

WinSCP-5 and PuTTYZip files

WinSCP is a popular SFTP client and FTP client for Microsoft Windows!, Configuration Storage Import/Export WinSCP.ini.

PuTTY is a free (MIT-licensed) Windows Telnet and SSH client. PuTTY Session Configuration. Tools > Preferences... > Integration - Applications > ...

The Applications Integration Page (Preferences Dialog)

TortoiseSVN

TortoiseSVN is a really easy to use Revision control / version control / source control software for Windows. It is based on Apache™ Subversion (SVN)®; TortoiseSVN provides a nice and easy user interface for Subversion.

Native memory means the memory area outside normal JVM heap, but still within the total user space memory spared by OS for JVM process (for example on 32-bit Windows it is by default 2 GB). This space is reserved by JVM to store some internal data, such as Permanent Generation / Method Area etc.

Direct memory means you use native memory by means of java.nio.DirectByteBuffer.

Native heap means you use native memory by means of unsafe.allocateMemory or simply do a malloc in your JNI code.

Off-heap is the same as native memory.

File Upload

java.nio « Since: 1.4
    BufferOverflowException extends RuntimeException
    BufferUnderflowException extends RuntimeException

Class loading Example:

class AAA {
    static {
        System.out.println("Static A");
    }
    {
        System.out.println("Instance A");
    }
    AAA() { // Default Call to super(); Constructor
        System.out.println("Instance Constructor A");
    }
    void fun1() {
        System.out.println("A fun");
    }
}
class BBB extends AAA {
    static {
        System.out.println("Static B");
    }
    {
        System.out.println("Instance B");
    }
    BBB() { // Default Call to super(); Constructor
        System.out.println("Instance Constructor B");
    }
    @Override
    void fun1() {
        System.out.println("B fun");
    }
}
class Test {
    public static void main(String[] args) {
        AAA a = new BBB();
        a.fun1();
    }
}
/*
Static A
Static B
Instance A
Instance Constructor A
Instance B
Instance Constructor B
B fun
*/

Complete J2EE Notes:

site

Jar, Zip file Actions:

Jarcomp is a comparison tool for Jar files and Zip files. It's free and cross-platform.

If you have two jar files or two zip files, it will show you what the differences are in the contents. It shows which files have been added, which have been removed, and which are present in both archives. If a file is found in both, it will tell you whether the file has grown bigger or been reduced in size, or if it's the same size in both. If it's the same size, an md5 checksum can be made for both files to see whether they're really the same contents or just the same size.

It can be useful to compare different versions of the same archive, for example to check that no files were accidentally added or forgotten, and that all the changes to the files are the ones intended.

Screenshot from a Linux system showing a comparison of two jars

comparison of two jars

Java Decompiler

  • JD-GUI, a standalone graphical utility that displays Java sources from CLASS files.

Java Decompiler

  • Luyten « An Open Source Java Decompiler Gui

Accounts:

Account

PrimeFaces User Interface. PrimeNG is a collection of rich UI components for Angular .

Online HTML page editors using css, javascript and HTML elements.

Online UML Diagram Tool:

Untitled Diagram. UML sample for editing form github.

Text Compare

Check text uniqueness, compare two texts and show the difference between them in user-friendly view.

  • CopyLeaks
    You can now compare two text documents by using the online text compare application. The content that you want to compare can be in different formats, and you get to see the highlighted difference in results within seconds. Now you can know what exactly has been poorly paraphrased, or worse copied between two texts. With our text comparison tool, you can easily check for similarities between two different files.

  • Text Compare!
    Text Compare! is an online diff tool that can find the difference between two text documents. Just paste and compare.

  • Diff Checker is an online diff tool to compare text differences between two text files.

XML, JSON, SQL, HTML Formatter and Validators online:

I-net Crystal-Clear Reports (formerly known as i-net Crystal-Clear) is a Java-based cross-platform reporting application providing a report designer and a server component to create reports in numerous output formats like PDF, HTML, PS, RTF, XLS, TXT, CSV, SVG, XML, as well as being viewable in a Java applet or Swing component.

PDF Content Comparer Intuitive, intelligent comparison of your PDFs. test online comparison, Priceless Tesla online, offline gui licenseagreement

Your PDFs contain actual content, not just text or images. i-net PDFC intelligently compares the content in your files. Any differences are shown in a visually gorgeous display, akin to holding up two pieces of paper to the light.

, a free online file comparison tool.

DiffNow(TM) lets you compare text files, documents, binary files, and archives up to 2048KB in size. You can either upload the files you wish to compare or enter their URLs.

How To Do Almost Anything with PDF

DocTranslator

JAVA OBFUSCATOR - By Reverse-engineer we can get source of bytecode to avoid we go for Obfuscator

Java bytecode obfuscator and shrinker that improves your software deployment by prohibiting unwanted access to your source code and drastically shrinking the processed Jar files at the same time.

Protect Your Java Code — Through Obfuscators And Beyond

  • Name Obfuscation Name obfuscation is the process of replacing the identifiers you have carefully chosen to your company's coding standards, such as com.mycompany.TradeSystem.Security.checkFingerprint(), with meaningless sequences of characters, e.g. a.a0(). (Of course, a name obfuscator must process the entire application to ensure consistency of name changes across all classes and jars.)

An Internet search for "Java obfuscator" would return way too many results. For your convenience, I have reduced the list to a handful of actively maintained products, both commercial and free.

Product License Price
yGuard Freeware -
Allatori Proprietary $
Dash-O-Pro Proprietary $$$?
Stringer Proprietary $
Zelix Klassmaster Proprietary $
ProGuard Open Source -

Stack-Post Best Java obfuscator?

In a class-based object-oriented language, in general, state is carried by instances, methods are carried by classes, and inheritance is only of structure and behavior.

Method signature: It consists of method name and parameter list (number/type/order of the parameters). methodName(parametersList y). An instance method in a subclass with the same signature and return type as an instance method in the super-class overrides the super-class's method.

Java OOP concepts
Class  - Collection of a common features of a group of object [static/instance Fields, blocks and Methods]
Object - Instance of a class (instance fields)
Abstraction - Process of hiding complex info and providing required info like API, Marker Interfaces ...
Encapsulation(Security) - Class Binding up with data members(fields) and member functions.
Inheritance  (Reusability by placing common code in single class)
 1. Multilevel - {A -> B -> C} 2. Multiple - Diamond problem {A <- (B) -> C} [Java not supports] 3. Cyclic {A <-> B} [Java not supports]
 * Is-A   Relation - Class A extends B
 * Hash-A Relation - Class A { B obj = new B(); } - (Composition/Aggregation)
Polymorphism (Flexibility) 1. Compile-Time Overloading    2. Runtime Overriding  [Greek - "many forms"]


int[] arr = {1,2,3}; int arrLength = arr.length;   // Fixed length of sequential blocks to hold same data type
String str = "Yash"; int strLength = str.length(); // Immutable Object value can't be changed.

List<?> collections = new ArrayList<String>(); int collectionGroupSize = collections.size();
Map<?, ?> mapEntry = new HashMap<String, String>();
Set<?> keySet = mapEntry.keySet(); // Set of Key's
Set<?> entrySet = mapEntry.entrySet(); // Set of Entries [Key, Value]

// Immutable Objects once created they can't be modified. final class Integer/String/Employee
Integer val = Integer.valueOf("100"); String str2 = String.valueOf(100); // Immutable classes
final class Employee { // All Wrapper classes, java.util.UUID, java.io.File ...
    private final String empName; // Field as Final(values can be assigned only once) Only getter functions.
    public Employee(String name) { this.empName = name; }
}

Native Java Code for Hashtable.h, Hashtable.cpp SQL API.

You can check your current JDK and JRE versions on your command prompt respectively,

  • JDK javac -version [C:\Program Files\Java\jdk1.8.0_121\bin] o/p: javac 1.8.0_121
  • JRE java -version [C:\Program Files\Java\jdk1.8.0_121\bin] o/P: java version "1.8.0_102"

JAVA_HOME - Must be set to JDK otherwise maven projects leads to compilation error. [ERROR] No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK? C:\Softwares\OpenJDK\, 7-zip

Fatal error compiling: invalid target release: JRE and JDK must be of same version 1.8.0.XXX

Disable TLS 1.0 and 1.1security-libs/javax.net.ssl: TLS 1.0 and 1.1 are versions of the TLS protocol that are no longer considered secure and have been superseded by more secure and modern versions (TLS 1.2 and 1.3).

⚠️ **GitHub.com Fallback** ⚠️