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Posted 09 November 2007 - 09:53 AM
Greetings from the land of perpetual Sun and Sand, did I mention the sand. I am new to Java and having difficulty with this assignment for a class. We are asked to build a program that uses locations to figure how far away an object is from another and figure which one is closer. I am enclosing the code I have so far, including the Junit tester
. I am having trouble taking the input and storing it as a string (double latitude, double longitude, "and location name") 
. The program compiles as is, and passes all the junit tests but one (distance method). That one I know has something to do with the output from the method not being called correctly in the test, or initialized in the program correctly, but can't figure out which 
.
public class Location
{
// add instance variables
private double latitude;
private double longitude;
private double distance;
private String tag;
/**
* Default constructor for objects of class Location.
*/
public Location()
{
// your code here
tag = null;
latitude = 0.0;
longitude = 0.0;
}
/**
* Second constructor for objects of class Location.
*/
public Location(double inLatitude, double inLongitude, String inTag)
{
// your code here
this.latitude = inLatitude;
this.longitude = inLongitude;
this.tag = inTag; // do not think think this is correct
}
/**
* sets the location latitude.
*
* @param inLatitude Location latitude value.
*/
public void setLatitude(double inLatitude)
{
// your code here
this.latitude = inLatitude;
}
/**
* gets the location latitude.
*
* @return double The location latitude.
*/
public double getLatitude()
{
//if (this.tag == null) //the hint sheet had a return value of 0.0 but that
doesn't make sense
{
//return 0.0;
}
//else
{
return this.latitude;
}
}
/**
* sets the location longitude.
*
* @param inLongitude Location longitude value.
*/
public void setLongitude(double inLongitude)
{
// your code here
this.longitude = inLongitude;
}
/**
* gets the location longitude.
*
* @return double The location longitude.
*/
public double getLongitude()
{
//if (longDiff == this.longitude) // same thing return value of 0.0 doesn't make sense
{
// return 0.0;
}
//else
{
return this.longitude;
}
}
/**
* sets the location tag string.
*
* @param inTag Location tag string.
*/
public void setTag(String inTag)
{
// not sure if this is right to store the value from location to a string
this.tag = inTag;
}
/**
* gets the location tag string.
*
* @return String The location tag string.
*/
public String getTag()
{
// I am not sure if this is correct fro what I need
return this.tag;
/**
* calculates the relative distance to a location.
*
* @param newLocation The location to determine distance to.
*
* @return double The relative distance to the new location.
*/
public double distance(Location newLocation)
{
double latDiff = (latitude - newLocation.latitude);
double longDiff = (longitude - newLocation.longitude);
if (latDiff == 0.0 || longDiff == 0.0)
{
return 0.0;
}
else
{
distance = Math.sqrt((latDiff * latDiff) + (longDiff * longDiff));
return this.distance;
}
}
/**
* determines which of two locations is closer.
* If the two objects passed as parameters are the same distance
* from the location, a value of 0 is returned. If the first object
* passed is closer, a value of 1 is returned. If the second object
* is closer, a value of 2 is returned.
*
* @param location1 The location of the first object.
* @param location2 The location of the second object.
*
* @return int 0 if equal distance, 1 or 2 otherwise as per description.
*/
public int closer(Location location1, Location location2)
{
// replace this line with your code
double distance1 = this.distance(location1);
double distance2 = this.distance(location2);
if (Math.abs(distance1 - distance2) <= 1E-14)
{
return 0;
}
else if (distance1 < distance2)
{
return 1;
}
else //distance2 < distance1
{
return 2;
}
}
/**
* provides String containing location information.
*
* @return String shows latitude, longitude, and tag value.
*/
public String toString()
{
// replace this line with your code
return ("The Latitude is " + this.getLatitude() + ", " +
"the longitude is " + this.getLongitude());
}
}
In the Junit tester the problem occurs when trying to check the distance method
. All the other tests pass except that one, and I can not get the program to compile.
public class LocationTest extends junit.framework.TestCase
{
/**
* Default constructor for test class LocationTest.
*/
public LocationTest()
{
// default constructor
}
/**
* Sets up the test fixture.
*
* Called before every test case method.
*/
protected void setUp()
{
// anything needed prior to each test case
}
/**
* Tears down the test fixture.
*
* Called after every test case method.
*/
protected void tearDown()
{
// anything needed after test cases complete
}
/**
* Test the default constructor.
*/
public void testConstructor()
{
Location location = new Location();
assertNotNull(location);
}
/**
* Test the second constructor.
*/
public void testConstructor2()
{
Location location1 = new Location(-33.86, 151.21, "Sydney");
assertNotNull(location1);
}
/**
* Test the setLatitude method.
*/
public void testSetLatitude()
{
Location home = new Location();
home.setLatitude(31.10);
assertEquals(31.10, home.getLatitude(), 0.01);
}
/**
* Test the getLatitude method.
*/
public void testGetLatitude()
{
Location home = new Location();
home.setLatitude(15.50);
assertEquals(15.50, home.getLatitude(), 0.01);
}
/**
* Test the SetLongitude method.
*/
public void testSetLongitude()
{
Location home = new Location();
home.setLongitude(115.50);
assertEquals(115.50, home.getLongitude(), 0.01);
}
/**
* Test the GetLongitude method.
*/
public void testGetLongitude()
{
Location home = new Location();
home.setLongitude(1.25);
assertEquals(1.25, home.getLongitude(), 0.01);
}
/**
* Test the SetTag method.
*/
public void testSetTag()
{
Location first = new Location(131.00, -26.00, "Livingston");
first.setTag("Seattle");
assertEquals("Seattle", first.getTag());
}
/**
* Test the GetTag method.
*/
public void testGetTag()
{
Location first = new Location(31.00, 26.00, "Woodville");
first.setTag("New York");
assertEquals("New York", first.getTag());
}
/**
* Test the Distance method.
*/
public void testDistance()
{
Location location1 = new Location(-33.86, 151.21, "Sydney");
Location location2 = new Location(40.42, -3.69, "Madrid");
assertEquals(171.83, this.distance); //does not recognise the variable or method distance
}
/**
* Test the Closer method.
*/
public void testCloser()
{
Location location1 = new Location(-33.86, 151.21, "Sydney");
Location location2 = new Location(40.42, -3.69, "Madrid");
Location location3 = new Location(51.51, -0.13, "London");
Location location4 = new Location(41.42, -3.69, "Madrid2");
Location location5 = new Location(39.42, -3.69, "Madrid3");
Location location6 = new Location(40.42, -2.69, "Madrid4");
Location location7 = new Location(40.42, -4.69, "Madrid5");
// test same distance (using same location)
assertEquals(0, location1.closer(location2, location2));
}
/**
* Test the ToString method.
*/
public void testToString()
{
Location location1 = new Location(-33.86, 151.21, "Sydney");
assertTrue(location1.toString().contains("151.21"));
}
}
I would really appreciate any help with this. I am about ten hours ahead here in Iraq, so if I don't respond immediately I apologize.
MultiQuote
. Any suggestions will be most helpful.
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