【笔记】Eclipse and Java for Total Beginners—006

Lesson 06 – Using Test-First Development in Eclipse

• Use test-first approach to write the Person toString() method
• Method overriding
• Field Hiding

1. toString() method

• inherited from Object class
• returns a String representation of the object
• normally create for every class

2. Test-driven development

• Think about what the method should do.
• Write a test case that will test this method.
• Write the new method.
• Test the new method.
• when it passes.. we’re done!

3. Test-driven development benefits

• Forced to create detailed specifications before coding.
• Test method serves as specification, documentation, and as unit test.
• When method passes the test, method is complete and correct.

package org.totalbeginner.tutorial;

 import org.totoalbeginner.tutorial.Person;

 import junit.framework.TestCase;

 public class PersonTest extends TestCase {

    public void testPerson() {
        Person p1 = new Person();
        assertEquals("unknown name", p1.getName());
        assertEquals(3, p1.getMaximumBooks());
    }

    public void testSetName() {
        Person p2 = new Person();
        p2.setName("Fred");
        assertEquals("Fred", p2.getName());
    }

    public void testSetMaximumBooks() {
        Person p3 = new Person();
        p3.setMaximumBooks(10);
        assertEquals(10, p3.getMaximumBooks());
    }
    
    public void testToString() {
        Person p4 = new Person();
        p4.setName("Fred Flintstone");
        p4.setMaximumBooks(7);
        String testString = "Fred Flintstone (7 books)";
        assertEquals(testString, p4.toString());
    }

}

package org.totoalbeginner.tutorial;

 public class Person {
    
    // fields
    private String name;    // name of the person
    private int maximumBooks;    // most books the person can check out
    
    // constructors
    public Person() {
        name = "unknown name";
        maximumBooks = 3;
    }
    
    // methods
    public String getName() {
        return name;
    }
    
    public void setName(String anyName) {
        name = anyName;    
    }

    public int getMaximumBooks() {
        return maximumBooks;
    }

    public void setMaximumBooks(int maximumBooks) {
        this.maximumBooks = maximumBooks;
    }
    
    public String toString() {
        return this.getName() + " (" + getMaximumBooks()
        + " books)";
    }

}