TRIGGERBLOCK

Saturday, March 12, 2016

Java : Looping (Iterator)

Looping (Iterator)

Iterator :

Collections = Lists(arraylist) , Set(HashSet -remove duplicates) , Map(similar to dictionary)

Java iterator is an interface.
belongs to collection framework
allow us to traverse the the data element without bothering implementation. Ex : User may use array ,list etc.,
Basically List and set collection provides the iterator ( ArrayList, LinkedList, and TreeSet etc)
Map implementation such as HashMap doesn’t provide Iterator directly

Using Iterator

Create an iterator
Have the loop iterate as long as hasNext( ) returns true.
Within the loop, obtain each element by calling next( ).

Array List
ArrayList<Student> s= new ArrayList<Student>();
s.add(new Student(Adam,98));
s.add(new Student(Bob,65));

for(int i=0;i<=s.size();i++)                //Noraml Loop
    System.out.println(s.get(i).name);

for(Student s_loop:s)                         //Enhanced Loop
    System.out.println(s_loop.name);

for (Iterator i=s.iterator();s.hasnext()){    //Iterator
    Student s_loop=(Student)i.next();
    System.out.println(s_loop.name);
    }

Array
Student[] s =new Student[2];
Student Adam=new Student("Adam",98);
Student Bob=new Student("Bob",67);

s[0]=Adam;
s[1]=Bob;

for(int i=0;i<=s.length-1;i++)
    System.out.println(s[i].name);


You can use Iterator Patten when you want similar implementation in both List and Array
1. ArrayList already comes ready with iterator so need to worry about that
2. We need to implement for Array or Class which uses array without changing the code.
(326pg -Design Patterns,Head First)
Or
1. Use Guava
Iterator<String> it = Iterators.forArray(array);

Examples :

1. HashMap

//Use Java 1.8
HashMap m=new HashMap();
m.put(1, "01");
m.put(2, "02");

m.forEach( (k,v) -> System.out.println("Key: " + k + ": Value: " + v));

or
Iterator entries = myMap.entrySet().iterator();
while (entries.hasNext()) {
Entry thisEntry = (Entry) entries.next();
Object key = thisEntry.getKey();
Object value = thisEntry.getValue();
// ...
}

2. Array List
ArrayList a=new ArrayList();
a.add(1);
a.add("hi");

Iterator it=a.iterator();
while(it.hasNext()){
System.out.println(it.next());
}

3.HashSet
HashSet s=new HashSet();
s.add("hi");
s.add("hi");
s.add("abc");
s.add("bye");

Iterator i=s.iterator();
while(i.hasNext())
{
System.out.println(i.next());
}

Example 2

public class CrunchifyIterateThroughList {

public static void main(String[] argv) {

List<String> crunchifyList = new ArrayList<String>();

crunchifyList.add("eBay");

crunchifyList.add("Paypal");

crunchifyList.add("Google");

crunchifyList.add("Yahoo");

// iterate via "for loop"

for (int i = 0; i < crunchifyList.size(); i++) {

System.out.println(crunchifyList.get(i));

}

// iterate via "New way to loop"

for (String temp : crunchifyList) {

System.out.println(temp);

}

// iterate via "iterator loop"

Iterator<String> crunchifyIterator = crunchifyList.iterator();

while (crunchifyIterator.hasNext()) {

System.out.println(crunchifyIterator.next());

}

// iterate via "while loop"

int i = 0;

while (i < crunchifyList.size()) {

System.out.println(crunchifyList.get(i));

i++;

}

// collection stream() util: Returns a sequential Stream with this collection as its source

crunchifyList.forEach((temp) -> {

System.out.println(temp);

});

}

Thursday, March 10, 2016

TestNg: @BeforeTest

@BeforeTest

BeforeTest execution = No of times you have defines <test name>.Below example you have used <test name> twice therefore Beforetest excutes twice

import org.testng.annotations.*;

public class testng_annotations {

    @BeforeSuite
    public void Beforesuite(){
        System.out.println("beforesuite");
    }

    @BeforeTest
    public void Beforetest(){
        System.out.println("beforetest");
    }

    @DataProvider
    public Object[][] dataprovider(){
        Object[][] obj=new Object[2][2];
        obj[0][0]=1;
        obj[1][0]=2;
        obj[0][1]=3;
        obj[1][1]=4;
        return obj;
    }

    @Test(dataProvider="dataprovider")
    public void test(int i,int y) {
            System.out.println("Data " + i+y);// execute 2nd
    }
}

Result

Wednesday, March 9, 2016

TestNg : Loop testcases logic (Reflection and ITestContext)

Loop testcases logic (Reflection and ITestContext)

Code Below :

public class BeforeMethodParametersExample {
    private Method method;
    private ITestContext context;
    private static final Object[][] DATA1 = { new Object[] { "first" },new Object[] { "second" }, };
    private int i;

    @DataProvider
    public Object[][] data1() {
        i=i+1;
        System.out.println("data provider "+1); //executes 1st
        return DATA1;//first , second
    }

    //Method java.lang.reflect.Method;   ITestContext //executes 2nd

@BeforeMethod
    public void before(Method m, ITestContext ctx) {
        method = m;
        context = ctx;
        i=i+1;
        System.out.println("Name of test is " + method.getName()+" "+i); // execute 1st
    }

    @BeforeMethod // -3rd
    public void beforeWithData(Object[] data) {
        for (Object o : data) {
            i=i+1;
            System.out.println("Data " + o+" "+i);// execute 2nd
        }
    }

    @Test(dataProvider="data1") //4th
    public void someTest(String data) {
        i=i+1;
        System.out.println("Name of test is " + method.getName()+" "+i);
        System.out.println("Suite name is " + context.getSuite().getName()+" "+i);
    }

}