Trouble with copy method, equals method and null data in Java
Question
Hello everyone I was wondering you guys might be able to give me a little bit of help with some Java issues I'm having. I'm working on a project that involves several classes that track different aspects of an airport, the issues I'm having are revolving around the pilot class. My issues are with the following according to my test:
- Fail in TestPrelab2. Name field is null after running setName and getName with null data. Make sure mutator sets name to empty string on null data. Make sure accessor isn't incorrectly returning null values.
- Fail in TestPrelab2. The equals method returned true when name is different but license is the same in two different objects.
- My copy method is also failing, but I'm not getting any explanation as to why.
I've tried solving all of these according to how my textbook explains it, but I haven't had very much luck. The tests for the project don't contain any useful information either unfortunately. Thank you for any input and advice you may have.
/**
* Pilot.java
**/
//Imports below
/**
* Class to store information about airplane pilots.
*
* @author Nicholas Thomas
* @version 04/4/2018
*/
public class Pilot
{
//Instance variables below
private String name;
private String license;
/** No-arg constructor for pilot class.
* No parameter constructor for objects of class Pilot.
*/
public Pilot()
{
name = "";
license = "";
}
/** Constructor for pilot class using name and license.
* Pilot Constructor
*
* @param name A parameter
* @param license A parameter
*/
public Pilot(String name, String license)
{
this.name = name;
this.license = license;
}
/** Mutator to modify the name field.
* Method setName
*
* @param name A parameter
*/
public void setName(String name)
{
this.name = name;
name = "";
}
/** Mutator to modify the license field.
* Method setLicense
*
* @param license A parameter
*/
public void setLicense(String license)
{
this.license = license;
license = "";
}
/** Accessor for the name instance.
* Method getName
*
* @return The return value
*/
public String getName()
{
return name;
}
/** Accessor for the license instance.
* Method getLicense
*
* @return The return value
*/
public String getLicense()
{
return license;
}
/** Method to copy.
* Method copy
*
* @return The return value
*/
public Pilot copy()
{
Pilot p1 = new Pilot(name, license);
Pilot p2;
p2 = p1.copy();
return p2;
}
/** Method to convert to string.
* Method toString
*
* @return The return value
*/
public String toString()
{
String p1 = "Name: " + name + " - "
+ "License: " + license;
return p1;
}
/** Method to determine if something equals something.
* Method equals
*
* @param pilot A parameter
* @return The return value
*/
public boolean equals(Pilot pilot)
{
return true;
}
}
I'm not sure if it will help any, but here's the code for the test I'm running.
/**
* TestPrelab2.java
*/
import static org.junit.Assert.fail;
import org.junit.Test;
import org.junit.Rule;
import org.junit.rules.Timeout;
/**
* Describe TestPrelab2 here.
*
* @author Joel Swanson
* @version 03.07.2014
*/
public class TestPrelab2
{
@Rule
public Timeout timeout = new Timeout(30000);
/**
* Check mutators to make sure setName and setLicense work
* properly.
*/
@Test
public void checkAccessorsMutators001()
{
checkNameAMNormal("Tom");
checkNameAMNull();
checkLicenseAMNormal("1010A");
checkLicenseAMNull();
}
/**
* Check the constructors.
*/
@Test
public void checkConstructors002()
{
checkNoArgConstructor();
checkArgConstructor("Tom", "12345-2");
checkArgConstructor("Bill", "12A345");
}
/**
* Test the copy method.
*/
@Test
public void checkCopy003()
{
checkCopy("Tom", "12345-2");
checkCopy("Bill", "12A345");
}
/**
* Test the copy method with data.
* @param testName The data to put in for name.
* @param testLicense The data to put in for ssn.
*/
public void checkCopy(String testName, String testLicense)
{
String fb = "";
Pilot pilot1 = new Pilot(testName, testLicense);
Pilot pilot2 = pilot1.copy();
if (pilot2 == null)
{
fb += "Fail in TestPrelab2.\n";
fb += "The copy method returned a null value.\n";
fail(fb);
}
else if (pilot1 == pilot2)
{
fb += "Fail in TestPrelab2.\n";
fb += "The copy method returned the actual pilot object\n"
+ "instead of making and returning a copy of the object.\n";
fail(fb);
}
else if (!pilot1.getName().equals(pilot2.getName()))
{
fb += "Fail in TestPrelab2.\n";
fb += "The copy method returned a pilot object with a name\n";
fb += "that is different than the original pilot object.\n";
fail(fb);
}
else if (!pilot1.getLicense().equals(pilot2.getLicense()))
{
fb += "Fail in TestPrelab2.\n";
fb += "The copy method returned a pilot object with a license\n";
fb += "that is different than the original pilot object.\n";
fail(fb);
}
}
/**
* Check the toString method.
*/
@Test
public void checkToString004()
{
String fb = "";
Pilot pilot = new Pilot("Alice", "112233");
String data = pilot.toString();
if (data == null)
{
fb += "Fail in TestPrelab2.\n";
fb += "The toString method returned a null value.\n";
fail(fb);
}
else if (data.contains("\n") || data.contains("\t"))
{
fb += "Fail in TestPrelab2.\n";
fb += "The toString method returned incorrect data.\n";
fb += "The value from toString should not contain tab"
+ " or newline characters.\n";
fail(fb);
}
else if (!data.equals("Name: Alice - License: 112233"))
{
fb += "Fail in TestPrelab2.\n";
fb += "The toString method returned incorrect data.\n";
fb += "Expected: Name: Alice - License: 112233\n";
fb += "Your value: " + data + "\n";
fb += "Careful with spacing.\n";
fail(fb);
}
pilot = new Pilot("Tommy", "555555");
data = pilot.toString();
if (data == null)
{
fb += "Fail in TestPrelab2.\n";
fb += "The toString method returned a null value.\n";
fail(fb);
}
else if (data.contains("\\n") || data.contains("\\t"))
{
fb += "Fail in TestPrelab2.\n";
fb += "The toString method returned incorrect data.\n";
fb += "The value from toString should not contain tab"
+ " or newline characters";
fail(fb);
}
else if (!data.equals("Name: Tommy - License: 555555"))
{
fb += "Fail in TestPrelab2.\n";
fb += "The toString method returned incorrect data.\n";
fb += "Expected: Name: Tommy - License: 555555\n";
fb += "Your value: " + data + "\n";
fb += "Careful with spacing.\n";
fail(fb);
}
}
/**
* Check the equals method.
*/
@Test
public void checkEquals005()
{
String fb = "";
String aliceB = "AliceB";
String licenseB = "112233B";
Pilot pilot1 = new Pilot("Alice", "112233");
Pilot pilot2 = new Pilot(aliceB.substring(0, 5),
licenseB.substring(0, 6));
if (!pilot1.equals(pilot2))
{
fb += "Fail in TestPrelab2.\n";
fb += "The equals method returned false when name and\n";
fb += "license are the same in two different objects.\n";
fb += "Make sure you are not using == to compare strings.\n";
fail(fb);
}
pilot1 = new Pilot("Alice", "112233");
pilot2 = new Pilot("Bill", licenseB.substring(0, 6));
if (pilot1.equals(pilot2))
{
fb += "Fail in TestPrelab2.\n";
fb += "The equals method returned true when name is different\n";
fb += "but license is the same in two different objects.\n";
fail(fb);
}
pilot1 = new Pilot("Alice", "112233");
pilot2 = new Pilot(aliceB.substring(0, 5), "223344");
if (pilot1.equals(pilot2))
{
fb += "Fail in TestPrelab2.\n";
fb += "The equals method returned true when name is the same\n";
fb += "but license is different in two different objects.\n";
fail(fb);
}
pilot1 = new Pilot("Alice", "112233");
pilot2 = new Pilot("Bill", "223344");
if (pilot1.equals(pilot2))
{
fb += "Fail in TestPrelab2.\n";
fb += "The equals method returned true when name is different\n";
fb += "and license is different in two different objects.\n";
fail(fb);
}
}
/**
* Check the name accessor and mutator with normal valid data.
* @param testData The name to set for testing.
*/
public void checkNameAMNormal(String testData)
{
String fb = "";
Pilot pilot = new Pilot();
pilot.setName(testData);
String setData = pilot.getName();
if (setData == null)
{
fb += "Fail in TestPrelab2.\n";
fb += "Name field is null after running setName\n";
fb += "and getName with valid data.\n";
fb += "Name accessor or mutator is incorrect.\n";
fail(fb);
}
else if (!setData.equals(testData))
{
fb += "Fail in TestPrelab2.\n";
fb += "Name field is incorrect after running\n";
fb += "setName and getName with valid data.\n";
fb += "Name accessor or mutator is incorrect.\n";
fail(fb);
}
}
/**
* Check the license accessor and mutator for proper operation.
* @param testData The license to set for testing.
*/
public void checkLicenseAMNormal(String testData)
{
String fb = "";
Pilot pilot = new Pilot();
pilot.setLicense(testData);
String setData = pilot.getLicense();
if (setData == null)
{
fb += "Fail in TestPrelab2.\n";
fb += "License field is null after running setLicense\n";
fb += "and getLicense with valid data.\n";
fb += "License accessor or mutator is incorrect.\n";
fail(fb);
}
else if (!setData.equals(testData))
{
fb += "Fail in TestPrelab2.\n";
fb += "License field is incorrect after running\n";
fb += "setLicense and getLicense with valid data.\n";
fb += "License accessor or mutator is incorrect.\n";
fail(fb);
}
}
/**
* Make sure the mutator does not allow null data.
*/
public void checkNameAMNull()
{
String fb = "";
Pilot pilot = new Pilot();
pilot.setName("ABCD");
pilot.setName(null);
String setData = pilot.getName();
if (setData == null)
{
fb += "Fail in TestPrelab2.\n";
fb += "Name field is null after running setName"
+ " and getName with null data.\n";
fb += "Make sure mutator sets name to empty"
+ " string on null data.\n";
fb += "Make sure accessor isn't incorrectly"
+ " returning null values.\n";
fail(fb);
}
else if (!setData.equals(""))
{
fb += "Fail in TestPrelab2.\n";
fb += "Name field is not empty string after running"
+ " setName and getName with null data.\n";
fb += "Make sure the mutator sets name to empty"
+ " string on null data.\n";
fb += "Make sure the accessor isn't incorrectly"
+ " returning the wrong value.\n";
fail(fb);
}
}
/**
* Make sure the mutator does not allow null data.
*/
public void checkLicenseAMNull()
{
String fb = "";
Pilot pilot = new Pilot();
pilot.setLicense("ABCD");
pilot.setLicense(null);
String setData = pilot.getLicense();
if (setData == null)
{
fb += "Fail in TestPrelab2.\n";
fb += "License field is null after running setlicense"
+ " and getLicense with null data.\n";
fb += "Make sure mutator sets license to empty"
+ " string on null data.\n";
fb += "Make sure accessor isn't incorrectly"
+ " returning null values.\n";
fail(fb);
}
else if (!setData.equals(""))
{
fb += "Fail in TestPrelab2.\n";
fb += "License field is not empty string after running"
+ " setLicense and getLicense with null data.\n";
fb += "Make sure the mutator sets license to empty"
+ " string on null data.\n";
fb += "Make sure the accessor isn't incorrectly"
+ " returning the wrong value.\n";
fail(fb);
}
}
/**
* Test argument constructor.
*
* @param name The name to test with this Pilot.
* @param license The license to test with this Pilot.
*/
public void checkArgConstructor(String name, String license)
{
String fb = "";
Pilot pilot = new Pilot(name, license);
if (!pilot.getName().equals(name))
{
fb += "Fail in TestPrelab2.\n";
fb += "Pilot argument constructor improperly set name.\n";
fail(fb);
}
if (!pilot.getLicense().equals(license))
{
fb += "Fail in TestPrelab2.\n";
fb += "Pilot argument constructor improperly set name.\n";
fail(fb);
}
}
/**
* Test the no-arg constructor. Should set the fields
* to empty strings.
*/
public void checkNoArgConstructor()
{
String fb = "";
Pilot pilot = new Pilot();
if (pilot.getName() == null)
{
fb += "Fail in TestPrelab2.\n";
fb += "Pilot no-arg constructor did not set name"
+ " field to empty string.\n";
fail(fb);
}
if (pilot.getLicense() == null)
{
fb += "Fail in TestPrelab2.\n";
fb += "Pilot no-arg constructor did not set license "
+ "field to empty string.\n";
fail(fb);
}
}
}
1 answers
solution1
1 ACCPTED 2018-04-10 01:10:51
1) Fail in TestPrelab2. Name field is null after running setName and getName with null data. Make sure mutator sets name to empty string on null data. Make sure accessor isn't incorrectly returning null values: Will be fixed by the following changes -
public Pilot(String name, String license){
setName(name);
setLicense(license);
}
public void setLicense(String license) {
this.license = (license == null) ? "" : license;
}
public void setName(String name) {
this.name = (name == null) ? "" : name;
}
2) Fail in TestPrelab2. The equals method returned true when name is different but license is the same in two different objects: Refactor always true method -
public boolean equals(Pilot pilot)
{
//return true;
return this.name.equals(pilot.getName()) && this.license.equals(pilot.getLicense());
}
3) My copy method is also failing, but I'm not getting any explanation as to why. Refactor -
public Pilot copy()
{
return new Pilot(name, license);
}
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