【笔记】Eclipse and Java for Total Beginners—012
Lesson 12 – Create checkOut, checkIn Methods
- Create test for checkOut, checkIn methods
- Write checkout method
- Introduce if / then / else syntax
- Introduce boolean method
- Write checkIn method
1. testCheckOut Method
Test both the checkOut and checkIn methods
- Check Out a book
- Check Out second book
- Check in a book
- Check in second book
- assert statements after each method call
2. checkOut Method Design
- Enter Person object into person field of Book
- Use setPerson(Person) method
- What if book is already checked out? Will not allow this.
- Need to test for this in checkOut method
- Method might succeed or fial, depending on situation.
- Should we tell the calling method whether it succeeded of failed ? yes.
3. checkOut Method Pseudo Code
- Check that this book is not already checked out.
- If it is not checked out, set the person field in the book to this person and let calling method know it worked.
- Otherwise, Let calling method know it didn’t work.
4. checkOut Method Signature
- Will return a boolean (true or false) to indicate success.
- In pseudo code, we had this book and this person – which book and person?
- Book and Person will be method parameters – checkOut (Book b, Person P)
- public boolean checkOut(Book b, Person p)
1
package
org.totalbeginner.tutorial;
2
3
import
java.util.ArrayList;
4
5
import
org.omg.CORBA.PUBLIC_MEMBER;
6
import
org.totoalbeginner.tutorial.Person;
7
8
import
junit.framework.TestCase;
9
10
public
class
MyLibraryTest
extends
TestCase {
11
private
Book b1;
12
private
Book b2;
13
private
Person p1;
14
private
Person p2;
15
private
MyLibrary ml;
16
17
public
void
testMyLibrary() {
18
MyLibrary ml
=
new
MyLibrary(
"
Test
"
);
19
20
assertEquals(
"
Test
"
, ml.name);
21
22
assertTrue(ml.books
instanceof
ArrayList);
23
assertTrue(ml.people
instanceof
ArrayList);
24
25
26
}
27
28
public
void
setup(){
29
b1
=
new
Book(
"
Book1
"
);
30
b2
=
new
Book(
"
Book2
"
);
31
32
p1
=
new
Person();
33
p2
=
new
Person();
34
p1.setName(
"
Fred
"
);
35
p2.setName(
"
Sue
"
);
36
37
ml
=
new
MyLibrary(
"
Test
"
);
38
}
39
40
public
void
testAddBook(){
41
//
create test objects
42
setup();
43
44
//
test initial size is 0
45
assertEquals(
0
,ml.getBooks().size());
46
47
ml.addBook(b1);
48
ml.addBook(b2);
49
50
assertEquals(
2
, ml.getBooks().size());
51
assertEquals(
0
, ml.getBooks().indexOf(b1));
52
assertEquals(
1
,ml.getBooks().indexOf(b2));
53
54
ml.removeBook(b1);
55
assertEquals(
1
, ml.getBooks().size());
56
assertEquals(
0
, ml.getBooks().indexOf(b2));
57
58
ml.removeBook(b2);
59
assertEquals(
0
, ml.getBooks().size());
60
61
public
void
testCheckOut() {
62
//
set up objects
63
setup();
64
65
ml.addBook(b1);
66
ml.addBook(b2);
67
ml.addPerson(p1);
68
ml.addPerson(p2);
69
70
assertTrun(
"
Book did not check out correctly
"
,
71
ml.checkOut(b1,p1));
72
73
assertEquals(
"
Fred
"
,b1.getPerson().getName());
74
75
assertFalse(
"
Book was already checked out
"
,
76
ml.checkOut(b1,p2));
77
78
assertTrue(
"
Book check in failed
"
, ml.checkIn(b1));
79
80
assertFalse(
"
Book was already checked in
"
, ml.checkIn(b1));
81
82
assertFalse(
"
Book was never checked out
"
, ml.checkIn(b2));
83
84
85
86
87
}
88
}
89
90
}
1
package
org.totalbeginner.tutorial;
2
3
import
java.util.ArrayList;
4
5
import
org.totoalbeginner.tutorial.Person;
6
7
public
class
MyLibrary {
8
9
String name;
10
public
String getName() {
11
return
name;
12
}
13
14
public
ArrayList
<
Person
>
getPeople() {
15
return
people;
16
}
17
18
public
ArrayList
<
Book
>
getBooks() {
19
return
books;
20
}
21
22
ArrayList
<
Person
>
people;
23
ArrayList
<
Book
>
books;
24
25
public
MyLibrary(String name) {
26
this
.name
=
name;
27
books
=
new
ArrayList
<
Book
>
();
28
people
=
new
ArrayList
<
Person
>
();
29
30
}
31
32
public
void
addBook(Book b1) {
33
this
.books.add(b1);
34
35
}
36
37
public
void
removeBook(Book b1) {
38
this
.books.remove(b1);
39
40
}
41
42
public
void
addPerson(Person p1){
43
this
.people.add(p1);
44
}
45
46
public
void
removePerson(Person p1){
47
this
.people.remove(p1);
48
}
49
50
public
boolean
checkOut(Book b1, Person p2) {
51
if
(b1.getPerson()
==
null
) {
52
b1.setPerson(p1);
53
return
true
;
54
}
55
else
{
56
return
false
;
57
}
58
}
59
60
public
boolean
checkIn(Book b1) {
61
if
(bl.getPerson()
!=
null
) {
62
b1.setPerson(
null
);
63
return
true
;
64
}
65
else
{
66
return
false
;
67
}
68
}
69
}