article-snippets.java

SNIPPET 1 
// Before Java 7
List<Integer> myList = new ArrayList<Integer>();
// After Java 7
List<Integer> myList = new ArrayList<>();
// Before Java 9 
return new Callable<String>() {
    @Override 
    public String call() throws Exception {
        return null;
    }
};
// After Java 9
return new Callable<>() {
    @Override
    public String call() throws Exception {
        return null;
    }
};

SNIPPET 2 
// Before Java 7
BufferedReader reader1 = null;
try {
  reader1 = new BufferedReader(new FileReader("myFile.txt"));
  System.out.println(reader2.readLine());
} catch( IOException e ){
  e.printStackTrace();
} finally{
  try{
    if( reader1 != null ){
      reader1.close()
    } 
  } catch( IOException e ){
    e.printStackTrace();
  }
}

// After Java 7
BufferedReader reader1 = new BufferedReader(new FileReader("myFile.txt"));
try (BufferedReader reader2 = reader1) {
 System.out.println(reader2.readLine());
}


// After Java 9
BufferedReader reader1 = new BufferedReader(new FileReader("myFile.txt"));
try (reader1) {
  System.out.println(reader1.readLine());
}


SNIPPET 3
// Java 7
interface Java7Interface{
	int sum=0;  // public static final int sum=0; constants
	void fun(); // public abstract void fun(); abstract method
}

// Java 8
interface Java8Interface{
	int sum=0; //constants
	void method1(); //abstract method
    default void method2(){
    	//implementation in interface itself
    }
  	default static void method3(){
      // Static method implemented in interface
    }
}

// Java 9
interface Java9Interface{
	int sum=0; //constants
	void method1(); //abstract method
    default void method2(){
    	//implementation in interface itself
    }
  	default static void method3(){
        // Static method implemented in interface
    }
  	
  	private default void privateMethod1(){
        // This method is not accessible in its implementer
    } 
    private static default void privateMethod2(){
        // This method is not accessible in its implementer
    } 
}

// Snippet 4 

var list = new ArrayList<String>(); // infers ArrayList<String>
var stream = list.stream();         // infers Stream<String>