Sunday, May 29, 2011
JUnit Beginer Tutorial
JUnit is an open source framework designed by Kent Beck, Erich Gamma for the purpose of writing and running test cases for java programs. In the case of web applications JUnit is used to test the application with out server. This framework builds a relationship between development and testing process.
If we want to test any application, In standalone, we need to call the respective method’s main() method but there are so many problems in testing the flow using main() method.
In a web application, to test the flow we need to deploy it in the server so if there is a change then again we need to restart the server. Here also facing problems while testing the application.
- Writing main method checks is convenient because all Java IDEs provide the ability to compile and run the class in the current buffer, and certainly have their place forexercising an object’s capability. There are, however, some issues with this approach that make it ineffective as a comprehensive test framework:
- There is no explicit concept of a test passing or failing. Typically, the program outputs messages simply with System.out.println; the user has to look at this and decide if it is correct.
- main has access to protected and private members and methods. While you may want to test the inner workings of a class may be desired, many tests are really about testing an object’s interface to the outside world.
- There is no mechanism to collect results in a structured fashion.
- There is no replicability. After each test run, a person has to examine and interpret the results.
The JUnit framework addresses these issues, and more
- JUnit addresses the above issues, It’s used to test an existing class. Suppose, If we have Calculation class then, we need to write CalculationTest to test the Calculation class.
- Using JUnit we can save testing time.
- In real time, in the web application development we implement JUnit test cases in the DAO classes. DAO classes can be tested with out server.
- With JUnit we can also test Struts / Spring applications but most of the time we test only DAO classes. Even some times service classes also tested using JUnit.
- Go to http://www.junit.org/ and click on the downloads link<—|
- select download source in zip format.<—|
- Extract the zip folder, you can see the documentation, and jar files for source and execution.
- Create a Java Project (Project Name : JUnitTest)
- If you are using MyEclipse, JUnit.jar will be available with IDE itself, Right click on the project—>Properties—>Java Build Path—>Libraries—>Add Libraries—>JUnit—>Next—>Finish—>OK
- If you are Eclipse, then you need to manually add library to the buildpath. , Right click on the project—>Properties—>Java Build Path—>Libraries—>Add External Libraries—>JUnit—>Next—>Finish—>OK
- Right click on the project –>New—>Source Folder—>test
- Right click in the test –>New—>JUnit Test Case
The following screenshots will guide you through the above steps.
Here is your first Debut JUnit test program.
package org.j2eedev.math;
/*
* @author Umashankar
* http://j2eedev.org
* Beginer JUnit Tutorial
* */
import org.j2eedev.calc.Calculation;
import junit.framework.TestCase;
public class MathTest extends TestCase {
private int value1;
private int value2;
public MathTest(String testName) {
super(testName);
}
protected void setUp() throws Exception {
super.setUp();
value1 = 3;
value2 = 5;
}
protected void tearDown() throws Exception {
super.tearDown();
value1 = 0;
value2 = 0;
}
public void testAdd() {
int total = 8;
int sum = Calculation.add(value1, value2);
assertEquals(sum, total);
}
public void testFailedAdd() {
int total = 9;
int sum = Calculation.add(value1, value2);
assertNotSame(sum, total);
}
public void testSub() {
int total = 0;
int sub = Calculation.sub(4, 4);
assertEquals(sub, total);
}
}
package org.j2eedev.calc;
/*
* @author Umashankar
* http://j2eedev.org
* Beginer JUnit Tutorial
* */
public class Calculation {
public static int add(int a, int b) {
return a + b;
}
public static int sub(int a, int b) {
return a - b;
}
}
Following are the different methods available with Assert. Find the one, that suites you to test the classes in the application.
static void assertArrayEquals(byte[] expecteds, byte[] actuals)
Asserts that two byte arrays are equal.
static void assertArrayEquals(char[] expecteds, char[] actuals)
Asserts that two char arrays are equal.
static void assertArrayEquals(double[] expecteds, double[] actuals, double delta)
Asserts that two double arrays are equal.
static void assertArrayEquals(float[] expecteds, float[] actuals, float delta)
Asserts that two float arrays are equal.
static void assertArrayEquals(int[] expecteds, int[] actuals)
Asserts that two int arrays are equal.
static void assertArrayEquals(long[] expecteds, long[] actuals)
Asserts that two long arrays are equal.
static void assertArrayEquals(Object[] expecteds, Object[] actuals)
Asserts that two object arrays are equal.
static void assertArrayEquals(short[] expecteds, short[] actuals)
Asserts that two short arrays are equal.
static void assertArrayEquals(String message, byte[] expecteds, byte[] actuals)
Asserts that two byte arrays are equal.
static void assertArrayEquals(String message, char[] expecteds, char[] actuals)
Asserts that two char arrays are equal.
static void assertArrayEquals(String message, double[] expecteds, double[] actuals, double delta)
Asserts that two double arrays are equal.
static void assertArrayEquals(String message, float[] expecteds, float[] actuals, float delta)
Asserts that two float arrays are equal.
static void assertArrayEquals(String message, int[] expecteds, int[] actuals)
Asserts that two int arrays are equal.
static void assertArrayEquals(String message, long[] expecteds, long[] actuals)
Asserts that two long arrays are equal.
static void assertArrayEquals(String message, Object[] expecteds, Object[] actuals)
Asserts that two object arrays are equal.
static void assertArrayEquals(String message, short[] expecteds, short[] actuals)
Asserts that two short arrays are equal.
static void assertEquals(double expected, double actual)
Deprecated. Use assertEquals(double expected, double actual, double epsilon) instead
static void assertEquals(double expected, double actual, double delta)
Asserts that two doubles or floats are equal to within a positive delta.
static void assertEquals(long expected, long actual)
Asserts that two longs are equal.
static void assertEquals(Object[] expecteds, Object[] actuals)
Deprecated. use assertArrayEquals
static void assertEquals(Object expected, Object actual)
Asserts that two objects are equal.
static void assertEquals(String message, double expected, double actual)
Deprecated. Use assertEquals(String message, double expected, double actual, double epsilon) instead
static void assertEquals(String message, double expected, double actual, double delta)
Asserts that two doubles or floats are equal to within a positive delta.
static void assertEquals(String message, long expected, long actual)
Asserts that two longs are equal.
static void assertEquals(String message, Object[] expecteds, Object[] actuals)
Deprecated. use assertArrayEquals
static void assertEquals(String message, Object expected, Object actual)
Asserts that two objects are equal.
static void assertFalse(boolean condition)
Asserts that a condition is false.
static void assertFalse(String message, boolean condition)
Asserts that a condition is false.
static void assertNotNull(Object object)
Asserts that an object isn't null.
static void assertNotNull(String message, Object object)
Asserts that an object isn't null.
static void assertNotSame(Object unexpected, Object actual)
Asserts that two objects do not refer to the same object.
static void assertNotSame(String message, Object unexpected, Object actual)
Asserts that two objects do not refer to the same object.
static void assertNull(Object object)
Asserts that an object is null.
static void assertNull(String message, Object object)
Asserts that an object is null.
static void assertSame(Object expected, Object actual)
Asserts that two objects refer to the same object.
static void assertSame(String message, Object expected, Object actual)
Asserts that two objects refer to the same object.
static <T> void
assertThat(String reason, T actual, Matcher<T> matcher)
Asserts that actual satisfies the condition specified by matcher.
static <T> void
assertThat(T actual, Matcher<T> matcher)
Asserts that actual satisfies the condition specified by matcher.
static void assertTrue(boolean condition)
Asserts that a condition is true.
static void assertTrue(String message, boolean condition)
Asserts that a condition is true.
static void fail()
Fails a test with no message.
static void fail(String message)
Fails a test with the given message.
- A test case is used to run multiple tests.
To Define a Test case:
- Implement a subclass of TestCase
- Define instance variables that store the state.
- Initialize by overriding setUp() method.
- Clean-Up after a test by overriding tearDown() method.
- Here if we run application, it will show whether the test cases have passed or not. If all test cases are passed then, it will show green indicator in the IDE. It will show red color to indicate that some or all of the test cases have failed.
+—>Name of the method must begin with "test".
11:58 AM 0
Tuesday, April 26, 2011
How to capture a key in JavaScript? key events with libraries
Any web application developer who wants to work with keyboard short cuts in need of key events defined in JavaScript. To get the key code we use onkeyup, onkeydown and onkeypress events of javascript.
onkeydown : will capture event once key is pressed down (it will not wait fot it to come up again).
onkeyup : will capture event only once the key is come up again. This will not capture events which takes the focus away on key press like tab.
onkeypress : combination of keydown and keyup. A keypress will be called when a key is down and up again i.e. a complete keypress.
Observe the code below
We can write the script as follows
var KeyID = (window.event) ? event.keyCode : e.keyCode;
alert(KeyID);
} // ]]></script>
we can capture the key code when, the document is altered. i.e. document.onkeyup
var KeyID = (window.event) ? event.keyCode : e.keyCode;
alert(KeyID);
} // ]]></script>
.keypress() doesn’t capture keys like scroll lock, print screen etc.,
<head> <title>http://j2eedev.org-----Online Tutorials</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.4.3/jquery.min.js"></script>
<script type="text/javascript"> $(document).ready(function(){
$("#textkey").keypress(function(event) {
alert(event.which);
}); }); </script>
$(document).ready(function(){ $("#textkey").keypress(function(event) { alert(event.which); }); }); </script> </head> <body>
<input id="textkey" name="test" type="text" />
</body> </html>
dojo.connect : Even this also doesn’t support keys like scroll lock, print screen and tab etc.,
var element=dojo.byId(“textkey”);
dojo.connect(element,”onkeydown”,function(e){
alert(e.which);
}); </script>
11:52 AM 0
Designing Sequence diagrams to understand perfect flow of events