我是第一次为
Java课程介绍创建一个UML图.我无法弄清楚我的课程是否正确指向对方.

Guitar类应该指向测试类吗？另外,吉他课应该在考试的左边吗？任何指针都非常感谢,谢谢.

My UML diagram hosted on ImageShack
(我没有足够的ref点来插入图像)

代码如下

package guitartest;

import java.util.Scanner;

public class Guitar {

// Declare variables 
private int numberOfStrings;
private String stringName;
private boolean isTuned;
private boolean isPlaying;
private boolean isPlucking;


// Construct a guitar and set boolean fields to "false"
public Guitar(){
    this.isTuned = false;
    this.isPlaying = false;
    this.isPlucking = false;
}   // end constructor


// Prompt user to enter number of strings 
public int getNumberOfStrings() {
    Scanner sc = new Scanner(System.in);

    // Loop continues until a positive integer is entered
    do {
        System.out.println("Enter number of strings in integer format");
        while (!sc.hasNextInt()) {
            System.out.println("Error! That's not a number!");
            sc.next();
        }    // end while
        numberOfStrings = sc.nextInt();
     }    // end do-while loop
     while (numberOfStrings <= 0); 
    return numberOfStrings;
}   // end method getNumberOfStrings

// Prompt user to enter string names
public String getStringName() {
    Scanner sc = new Scanner(System.in);

    // Loop continues until all strings are named
    for (int i = 0; i < numberOfStrings; i++){
        System.out.println("Enter string name"); 
        // Error if input is not a character
        while (!sc.hasNext("[A-Za-z]")) {
            System.out.println("Error! That's not a character!");
            sc.next();
         }
        stringName = sc.next();
    }   // end for loop
    return stringName;
}   // end method getStringName

// Verifies tuning status
public boolean tuneInstrument(){
    return isTuned;
}   // end method tuneInstrument

// Tune guitar
public void setTuned(boolean isTuned) {
    this.isTuned = isTuned;
}   // end method setTuned

// Verifies instrument is playing
public boolean playInstrument(){
    return isPlaying;
}   // end method playInstrument

// 
public void startPlayingInstrument(){
    isPlaying = true;
}   // end method startPlayingInstrument

public boolean pluckInstrument(){
    return isPlucking;
}   // end method pluckInstrument

public void startPlucking(){
    isPlucking = true;
}   // end method startPlucking

// Stop instrument
public void stopInstrument(){
    isPlaying = false;
}   // end method stopInstrument

}   // end class Guitar

测试类如下：

package guitartest;

import java.util.Scanner;
// Scanner is in the java.util package

public class GuitarTest {

public static void main(String[] args) {

    // Create 10 guitar objects
    Guitar[] guitar = new Guitar[10];

    for (int i = 0; i < guitar.length; i++){
        guitar[i] = new Guitar();


    // Call methods in Guitar class
    guitar[i].getNumberOfStrings(); 
    guitar[i].getStringName();

    System.out.println("Is the guitar tuned? " + guitar[i].tuneInstrument());
    System.out.println("Guitar is being tuned. Please wait...");
    guitar[i].setTuned(true);
    System.out.println("Is the guitar tuned? " + guitar[i].tuneInstrument());

    System.out.println("Is the guitar playing? " + guitar[i].playInstrument());
    System.out.println("Please wait for guitar to play...");
    guitar[i].startPlayingInstrument();
    System.out.println("Is the guitar playing? " + guitar[i].playInstrument());

    System.out.println("Is the guitar being plucked? " + guitar[i].pluckInstrument());
    System.out.println("Please wait for guitar to be plucked...");
    guitar[i].startPlucking();
    System.out.println("The guitar is playing and being plucked. " + guitar[i].pluckInstrument());

    System.out.println("Stopping guitar from playing...");
    guitar[i].stopInstrument();
    System.out.println("Is the guitar playing? " + guitar[i].playInstrument());
    }   // end for loop

}   // end method main


}   // end class GuitarTest

最佳答案 你有一个主要问题 – 方向不应该是从吉他到吉他测试而是逆转 – 从GuitarTest到吉他(因为你在测试中使用吉他).你也忘记了GuitarTest.main的论点(显然不那么重要).

@milesma在评论中指出我最初是不正确的,我同意他的观点：

GuitarTest indeed used Guitar, but that is “Dependency” relationship.
(draw dashed line from Client to Supplier, in this example, from
GuitarTest to Guitar, which means, if Guitar changed, GuitarTest must
change); However, I don’t think use Guitar in the function body is a
dependency. (If Guitar is used as method’s parameter, return type etc,
then Dependency is guaranteed.). IMHO, there is no relationships
between.

更好地查看更正确的@milesma答案.