Code of Java Interview Question - http://www.lightblue.asia/java-interview-questions

java8-lambda.java

//Example 1: new Runnable 
Runnable run = new Runnable() {
	public void run() {
	    System.out.println("run me!");
	}
};
// one line lambda
Runnable run = () -> System.out.println("run me!");

// Exmaple 2: Iterate Map
Set keySet = map.keySet();
for (String s : keySet) {
	System.out.print(s + ":" + map.get(s));
}
// one line lambda
map.forEach((k, v) -> System.out.print(k + ":" + v));

java8-stream.java

List list = new ArrayList();
list.add("1");
list.add("2");
list.add("3");
list.add("5");
list.add("4");
list.stream().filter(s -> Integer.valueOf(s) < 3).forEach(s -> System.out.print(s));

singleton.java

public class MySingleton{  
    private static  MySingleton uniqueInstance;  
    private MySingleton(){} // 使用Private以確保mySingleton 只能透過 API:getInstance() 產生Instance
    public static synchronized  MySingleton getInstance() { 
        if(uniqueInstance == null ) {uniqueInstance = new mySingleton();}  
        return uniqueInstance;  
    }  
} 

test.java

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