JavaNoobPig

@Component
@Qualifier("bubble")
public class BubbleSortAlgorithm implements SortAlgorithm{
	public int[] sort(int[] numbers) {
		// Logic for Bubble Sort
		return numbers;
	}
}

JavaNoobPig

@Component
public class BinarySearchImpl {
	
	@Autowired
	@Qualifier("bubble")
	private SortAlgorithm sortAlgorithm;

	public int binarySearch(int [] numbers,int numberToSearchFor) {
		int[] sortedNumbers = sortAlgorithm.sort(numbers);
		System.out.println(sortAlgorithm);

JavaNoobPig

@SpringBootApplication  
public class SpringIn5StepsApplication {

	public static void main(String[] args) {		
		ApplicationContext applicationContext =
				SpringApplication.run(SpringIn5StepsApplication.class, args);
		
		BinarySearchImpl binarySearch = applicationContext.getBean(BinarySearchImpl.class);
		BinarySearchImpl binarySearch1 = applicationContext.getBean(BinarySearchImpl.class);
		

JavaNoobPig

@Component
@Scope("prototype")
public class BinarySearchImpl {
	
	@Autowired
	@Qualifier("bubble")
	private SortAlgorithm sortAlgorithm;

	public int binarySearch(int [] numbers,int numberToSearchFor) {
		int[] sortedNumbers = sortAlgorithm.sort(numbers);

JavaNoobPig

public class Test2DimArrayEx1 {

	public static void main(String[] args) {
	int [][] data= new int[2][3];
	
	data[0][0]=1;
	data[0][1]=2;
	data[0][2]=3;

	data[1][0]=4;

JavaNoobPig

public class TestVarArgsEx1 {
	public void sum(int... data) {
		int total = 0;

		for (int i = 0; i < data.length; i++) {
			total = total + data[i];
		}
		System.out.println("total=" + total);
	}

JavaNoobPig

public class TestStringEx1 {
	public static void main(String[] args) {
		String name = "John";
		System.out.println("John+1+2="+name+1+2);
		
		String name2="abcdefgh";
		System.out.println(name2.length());         //顯示字元長度
		System.out.println(name2.charAt(4));        //呼叫出由0開始的第4個字元
		System.out.println(name2.substring(4, 6));  //呼叫出4~6不包含6的字串
		System.out.println(name2.replaceAll("ab", "gg")); //將含有ab的字元取代為gg

JavaNoobPig

public class TestStringEx2 {
	public static void main(String[] args) {
		String name1 = "abc";
		boolean flag1=name1.matches("[a-z]");
		//後面沒有數字指定個數，即表示指定一個，但是abc為三個字母
		System.out.println("flag1="+flag1);
		
		boolean flag2=name1.matches("[a-z]{3}");
		//於a-z中包含3個字元
		System.out.println("flag2="+flag2);

JavaNoobPig

public class TestWrapperClassEx1 {

	public static void main(String[] args) {
		String message = "12345";
		System.out.println("message+1="+message+1);
		
		int num1 = Integer.parseInt(message);
		System.out.println("num1+1="+(num1+1));//有括號，執行數字運算
		System.out.println("num1+1="+num1+1);//沒括號，不執行數字運算
		

JavaNoobPig

public class TestWrapperClassEx2 {   

	public static void main(String[] args) {
	String value1 = args[0];  //假設args[0]帶450
	Integer i1=new Integer(value1);
	//Integer i2=8
	
	int number=i1;
	//int number=i1.value(); 等同上一行
	System.out.println("number開根號="+Math.sqrt(number));