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Start your free trialdlpuxdzztg
8,243 PointsI'm there!...almost...
So i'm trying to run the final challenge for 'Java Objects' (With everything un-commented and my title and description inserted), when I run my program...this error pops up:
Starting forum example...
java.lang.NullPointerException
at Forum.addPost(Forum.java:14)
at Example.main(Example.java:13)
at JavaTester.run(JavaTester.java:183)
at JavaTester.main(JavaTester.java:43)
Help is appreciated!
Also, my entire code:
public class ForumPost {
private User mAuthor;
private String mTitle;
private String mDescription;
public User getAuthor() {
return mAuthor;
}
public String getTitle() {
return mTitle;
}
public String getDescription() {
return mDescription;
}
public ForumPost(User author, String title, String Description) {
}
}
public class User {
private String mFirstName;
private String mLastName;
public User(String firstName, String lastName) {
mFirstName = firstName;
mLastName = lastName;
}
public String getFirstName() {
return mFirstName;
}
public String getLastName() {
return mLastName;
}
}
public class Forum {
private String mTopic;
public Forum(String topic) {
mTopic = topic;
}
public String getTopic() {
return mTopic;
}
public void addPost(ForumPost post) {
System.out.printf("New post from %s %s about %s.\n",
post.getAuthor().getFirstName(),
post.getAuthor().getLastName(),
post.getTitle());
}
}
public class Example {
public static void main(String[] args) {
System.out.println("Starting forum example...");
if (args.length < 2) {
System.out.println("first and last name are required. eg: java Example Craig Dennis");
}
Forum forum = new Forum("Java");
// Take the first two elements passed args
User author = new User(args[0], args[1]);
// Add the author, title and description
ForumPost post = new ForumPost(author, "I did it!", "Whoooo!");
forum.addPost(post);
}
}
1 Answer
Kourosh Raeen
23,733 PointsHi Diego - Your ForumPost constructor's body is empty. You need to initialize the member fields in there.
dlpuxdzztg
8,243 Pointsdlpuxdzztg
8,243 PointsAh! I knew there was something up with that constructor...Thanks alot! :)