Java Tutorial

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Java Loops

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Java Programs

Java Basic Programs Factorial Program in Java Fibonacci Series Program in Java Prime Number Program in Java Palindrome Number Program in Java Armstrong Number Program in Java Anagram Program in Java Pattern Programs in Java Calculator Program in Java Leap Year Program in Java Addition Program in Java Number Pattern Programs in Java Star Pattern Programs in Java Package Program in Java Pyramid Program in Java Sorting Program in Java String Palindrome Program in Java Even Odd Program in Java For Loop Program in Java If Else Program in Java Switch Case Program in Java GCD Program in Java LCM Program in Java Hello Program in Java Matrix Program in Java Menu Driven Program in Java Series Program in Java Client Server Program in Java Swapping Program in Java Pig Latin Program in Java Tower of Hanoi Program in Java Recursion Program in Java Matrix Multiplication Program in Java Perfect Number Program in Java Classes and Objects in Java Example Programs String Programs in Java Array Programs in Java Constructor Program in Java Inheritance Program in Java Abstract class Program in Java Interface Program in Java Encapsulation Program in Java Polymorphism Program in Java Exception Handling Program in Java Multithreading Program in Java Thread Program in Java Collection Programs in Java ArrayList Program in Java Stack Program in Java Applet Program in Java Swing Program in Java JDBC Program in Java How to run Java program in command prompt How to run Java program in Eclipse

Java Sorting

Sorting Algorithms in Java Merge Sort in Java Quick Sort in Java Bubble Sort in Java Insertion Sort in Java Selection Sort in Java Heap Sort in Java Radix Sort in Java Topological Sort in Java Bucket Sort in Java Counting Sort in Java

Java OOPs Concepts

OOPs - Object Oriented Programming Objects and Classes in Java Java Naming Conventions Constructors in Java Java this keyword Java static keyword Inheritance in Java Aggregation in Java Java super keyword Constructor Chaining and Constructor Overloading Java Polymorphism Static and Dynamic Binding in Java Java Abstraction Abstract class in Java Interface in Java Difference between Abstract class and Interface Java final keyword Packages in Java Access Modifiers in Java Java Wrapper classes Java Numbers Java Characters Java Integer Java Boolean Java Arrays Java Command Line Arguments Java strictfp Keyword Java Math

Java Strings

Java Strings Java String Methods StringBuilder in Java StringBuffer in Java Java Regular Expressions StringBuffer vs StringBuilder String vs StringBuffer String vs StringBuilder String Manipulation in Java Java String Concatenation How to Reverse a String in Java String Array in Java How to Compare Two Strings in Java How to Concatenate Two Strings in Java Why String in Immutable in Java java.lang.NumberFormatException for Input String String Pool in Java Java Generate Random String How to take String Input in Java Java String Interview Questions

Java Exceptions

Exception Handling in Java Java try catch Java throw Java throws Difference between throw and throws Java finally Java Custom Exception Java Exception Propagation

Garbage Collection

Automatic Resource Management in Java Java Garbage Collection Java finalize() Java gc() Difference between final, finally and finalize

Multithreading

Multithreading in Java Process and Thread in Java Basic Terms in Multithreading Java Thread creation Thread Scheduler in Java Java Thread class DeadLock in Java

Java IO

Java IO Java Read File Java BufferedWriter Java InputStreamReader Java File Java Read File Line By Line Java FileOutputStream Jar File in Java

Serialization

Java Serialization Java transient

Networking

Java Network Programming Java Socket Programming Java URL Java URLConnection HttpURLConnection in Java Java InetAddress Java DatagramSocket and Java DatagramPacket

AWT

Java AWT

Swing

Swing in Java

Java Collections

Collections in Java Java List Interface ArrayList in Java LinkedList in Java Vector in Java Stack in Java ArrayList vs LinkedList in Java ArrayList vs Vector in Java Java Set Interface HashSet in Java LinkedHashSet in Java TreeSet in Java Java Queue Interface PriorityQueue in Java ArrayDeque in Java Java Map Interface HashMap in Java LinkedHashMap in Java TreeMap in Java Dictionary in Java Hashtable in Java Properties in Java Collections class in Java Java Comparable Java Comparator Comparable vs Comparator in Java

Java Generics

Generics in Java

Java Annotations

Annotations in Java

Java JDBC

Java JDBC Tutorial

Java Differences

Java vs JavaScript Python vs Java Kotlin vs Java Java vs C++ C# vs Java Static vs Non-static in Java C vs Java int vs Integer in Java Stack vs Heap in Java Java Array vs ArrayList

How to

How to run Java program How to set path in Java How to check the Java version in cmd How to install Java in Windows 10 How to run Java program in cmd How to call a method in Java How to sort an array in Java How to iterate HashMap in Java How to write Java program How to create an array in Java How to create a package in Java How to generate random numbers in Java How to input String in Java How to create thread in Java How to find length of String in Java How to sort a string in Java How to use scanner in Java How to achieve multiple inheritance in Java How to run Java program in Eclipse How to call a function in Java How to create array of objects in Java How to create custom exception in Java How to achieve abstraction in Java How to call static method in Java

Java 8 Features

Java 8 Features Lambda Expressions in Java Functional Interface in Java Streams in Java Java Base64 Encoding and Decoding Parallel Arrays Sort in Java

Java 9 Features

Java 9 Tutorial Java 9 Try With Resources Java 9 Interface Private Method

Java Servlet Tutorial

Java Servlets Tutorial

Java JSP Tutorial

Java JSP Tutorial

Hibernate Tutorial

Hibernate Tutorial

Spring Tutorial

Spring Tutorial

Spring MVC Tutorial

Spring MVC Tutorial

Jenkins Tutorial

Jenkins Tutorial

Java Math Methods

Math.abs() Math.acos() Math.addExact() Math.asin() Math.atan () Math.atan2() Math.cbrt() Math.ceil() Math.copysign() Math.cos() Math.cosh() Math.decrementExact() Math.exp() Math.expm1() Math.floor() Math.floorDiv() Math.floorMod() Math.getExponent() Math.hypot() Math.IEEEremainder() Math.incrementExact() Math.log() Math.log10() Math.log1p() Math.max() Math.min() Math.multiplyExact() Math.multiplyFull() Math.negateExact() Math.nextAfter() Math.nextDown() Math.nextUp() Math.pow() Math.random() Math.rint() Math.round() Math.scalb() Math.signum() Math.sin() Math.sinh() Math.sqrt() Math.subtractExact() Math.tan() Math.tanh() Math.toDegrees() Math.toIntExact() Math.toRadians() Math.ulp()

Java String Methods

toCharArray() copyValueOf() endsWith() equals() equalsIgnoreCase() format() getBytes() getChars() hashCode() indexOf() intern() isEmpty() join() lastIndexOf() length() replace() replaceAll() replaceFirst() split() startsWith() subSequence() substring() toLowerCase() toUpperCase() trim() valueOf()

Java Conversion

Java Convert String to int Java Convert int to String Java Convert String to long Java Convert long to String Java Convert String to float Java Convert float to String Java Convert String to double Java Convert double to String Java Convert String to Date Java Convert Date to String Java Convert String to Object Java Convert Object to String Java Convert String to char Java Convert char to String Java Convert int to long Java Convert long to int

Misc

Functional Interfaces in Java Singleton class in Java Awesome explanation of Strings in Java Object class in Java Static class in Java All the important string methods in Java String Handling Method in Java What are Array strings in Java Advantages and Disadvantages of Strings in Java Big Decimal class in Java Class definition in Java Char and String differences in Java Difference between String, StringBuffer and StringBuilder in java Replace character in string Java String Coding Interview Questions in Java What is String in Java? String isnullorempty in Java String Matches in Java Trim Method in String Java Bean class in Java Libraries in Java Arithmetic Operations on String in Java Convert Char array to string in java Check whether Java is installed or not How to calculate time difference in Java How to stop execution after a certain time in Java Jagged Array in Java Java ArraylistRemove() Time Complexity Java Swing Time Picker Zigzag Array in Java

Properties Class in Java

Properties class is associated with Java since JDK 1.0, i.e. it is a legacy class. It is the subclass of Hashtable. It is used to maintain the lists of values in which the keys, as well as values, is of String type.

Property list can contain a second property list as its default and this list is searched only if the property key is not found in the main property list.

Property class is thread-safe, i.e. multiple threads can share a single properties object without any external synchronization. This is not a generic class but some of its methods are generic.

It defines the following instance variable:

Properties defaults It holds a default property list associated with the Properties object.

Properties define these constructors:

Properties() This constructor creates a Properties object with no default values.
Properties(Properties propDefault) It generates an empty property list with the specified default value.

Method of Properties Class

Modifiers Methods Description
String getProperty(String key) It returns the value associated with the specified key in the argument. It returns null if the key is neither in the list nor in the default property list.
String getProperty(String key, String defaultProperty) It returns the value associated with the specified key in the argument. defaultProperty is returned if the key is not present in the list as well as in the default property list.
void list(PrintStream streamOut) It sends the property list to the specified output stream linked to the streamOut.
  List(PrintWriter streamOut) It sends the property list to the specified output stream linked to the streamOut.
  load(InputStream streamIn throws IOException) It reads a property list (key and element pairs) from the specified input byte stream linked to streamIn.
  load(Reader streamIn throws IOException) It reads a property list from the input stream linked to streamIn.
  loadFromXML(InputStream streamIn) It loads all the property list represented by an XML document on the specified input stream.
  putAll(Map t) This method copy all of the mapping from the specified map to the hashtable.
  store(OutputStream streamOut, String description) It writes the property list of the Properties table to the specified output stream after writing the string specified by the description parameter.
  store(Writer writer, String comments) It writes the property list of the Properties table to the specified output stream after writing the string specified as comments
  storeToXML(OutputStream out, String comment) The property list is written to the XML document specified in the argument after writing the string specified as a comment.
  storeToXML(OutputStream out, String comment, String enc) The property list and the string specified in the argument is written to XML document linked in the argument.
Enumeration<?> propertyNames() It returns an enumeration of keys that includes those keys found also in the default property list.
Object setProperty(String key, String value) It calls the Hashtable method put, or returns the previous value associated with key or returns null if no associations exist.
Set<String> stringPropertyNames() It returns a set of keys that is unmodifiable, from the property list where key-value pair is the string that includes distinct key in the default property list if an identical key has not already been found from the main property list.
Collection<Object> Values() It returns a collection view of the values contained in the map.
Object merge(Object key, Object value, BiFunction remappingFunction) It associates the specified key with the specified non-null value if the specified key is not already associated with a value or null.

Example code to illustrate getProperty() method.

 import Java.util.*; 
 class GetProperrtyDemo 
 { 
     public static void main(String arg[]) 
     { 
         Properties p = new Properties(); 
         Set sub; 
         String str; 
         p.put("A", "Java"); 
         p.put("B", "Python"); 
         p.put("C", "SQL"); 
         // checking values in table 
         sub = p.keySet(); 
         Iterator itr = sub.iterator(); 
         while(itr.hasNext()) 
         { 
             str = (String)itr.next(); 
             System.out.println("Subject associated with " + str +  " is " + p.getProperty(str)); 
         } 
         System.out.println(); 
         // looking for subject that is in list 
         str = p.getProperty("Oracle", "not found"); 
         System.out.println("The Subject " + str); 
     } 
 } 

Output:

 Subject associated with A is Java
 Subject associated with C is SQL
 Subject associated with B is Python
 The Subject not found 

Example code to illustrating list() method.

 import Java.util.*; 
 class ListDemo 
 { 
     public static void main(String arg[]) 
     { 
         Properties p = new Properties(); 
         p.put("Ankit", "Java"); 
         p.put("Sumit", "DBMS"); 
         p.put("Akash", "Bash"); 
         p.list(System.out); 
     } 
 } 

Output:

 -- listing properties --
 Ankit=Java
 Sumit=DBMS
 Akash=Bash 

Exampple code to illustrate propertyNames() method.

 import Java.util.*; 
 class PropertyNameDemo 
 { 
     public static void main(String arg[]) 
     { 
         Properties p = new Properties(); 
         String s; 
         p.put("Ankit", "Java"); 
         p.put("Sumit", "DBMS"); 
         p.put("Akash", "Bash"); 
         Enumeration name = p.propertyNames(); 
         // displaying the enumaration of elements 
         System.out.println(name.nextElement()); 
         System.out.println(name.nextElement()); 
         System.out.println(name.nextElement()); 
     } 
 }  

Output:

 Ankit
 Sumit
 Akash 

Example code to illustrate setProperty() method.

 import Java.util.*; 
 class SetPropDemo 
 { 
     public static void main(String arg[]) 
     { 
         Properties p = new Properties(); 
         p.put("Amar", "Python"); 
         p.put("Akbar", "Java"); 
         p.setProperty("Anthony", "Microservices"); 
         System.out.println(p); 
     } 
 } 

Output:

{Anthony=Microservices, Akbar=Java, Amar=Python}

Example to illustrate the load and Store method.

 import Java.io.*;
 import Java.util.*;
 class StoreLoadDemo {
 public static void main(String args[])
 throws IOException
 {
                 Properties p = new Properties();
                 BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
                 String name, number;
                 FileInputStream fin = null;
                 boolean changed = false;
 // Try to open Student database.
                 try {
                                                 fin = new FileInputStream("D:\\StudentData.dat");
                                 } 
                 catch(Exception e) 
                 {
                                 e.printStackTrace();
                 }
                 /* If student file already exists, load existing students numbers. */
                 try {
                                                 if(fin != null) {
                                                                 p.load(fin);
                                                                 fin.close();
                                                 }
                 } 
                 catch(IOException e) 
                 {
                 System.out.println("Error reading file.");
                 }
                 // Let user enter new names and numbers.
                 do 
                 {
                 System.out.println("Enter new name" +" ('quit' to stop): ");
                 name = br.readLine();
                 if(name.equals("quit")) continue;
                 System.out.println("Enter number: ");
                 number = br.readLine();
                 p.put(name, number);
                 changed = true;
                 } 
                 while(!name.equals("quit"));
                 // If Student data has changed, save it.
                 if(changed) 
                 {
                 FileOutputStream fout = new FileOutputStream("D:\\StudentData.dat");
                 p.store(fout, "Student Database");
                 fout.close();
                 }
                 // Look up numbers given a name.
                 do {
                 System.out.println("Enter name to find" +" ('quit' to quit): ");
                 name = br.readLine();
                 if(name.equals("quit")) continue;
                 number = (String) p.get(name);
                 System.out.println(number);
                 } 
                 while(!name.equals("quit"));
  }
 } 

Output:

 Enter new name ('quit' to stop): 
 Ankit
 Enter number: 
 9013777664
 Enter new name ('quit' to stop): 
 Ashish
 Enter number: 
 1245799453
 Enter new name ('quit' to stop): 
 quit
 Enter name to find ('quit' to quit): 
 Ankit
 9013777664
 Enter name to find ('quit' to quit): 
 quit 



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