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Start your free trialDamjan Vlaic
19,244 Points---JAVA---
I don't know where did i made a mistake here. Can someone help pls ;)
I've added a new class called Blog. It is initialized with a list of BlogPost objects. Create a method in the Blog class called getAllAuthors that loops over all the posts and returns a java.util.Set of all the authors, which are stored as Strings. They should be sorted alphabetically.
package com.example;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
public class BlogPost implements Comparable<BlogPost>, Serializable {
private String mAuthor;
private String mTitle;
private String mBody;
private String mCategory;
private Date mCreationDate;
public BlogPost(String author, String title, String body, String category, Date creationDate) {
mAuthor = author;
mTitle = title;
mBody = body;
mCategory = category;
mCreationDate = creationDate;
}
public int compareTo(BlogPost other) {
if (equals(other)) {
return 0;
}
return mCreationDate.compareTo(other.mCreationDate);
}
public String[] getWords() {
return mBody.split("\\s+");
}
public List<String> getExternalLinks() {
List<String> links = new ArrayList<String>();
for (String word : getWords()) {
if (word.startsWith("http")) {
links.add(word);
}
}
return links;
}
public String getAuthor() {
return mAuthor;
}
public String getTitle() {
return mTitle;
}
public String getBody() {
return mBody;
}
public String getCategory() {
return mCategory;
}
public Date getCreationDate() {
return mCreationDate;
}
}
package com.example;
import java.util.List;
import java.util.Set;
import java.util.HashSet;
import java.util.TreeSet;
public class Blog {
List<BlogPost> mPosts;
public Blog(List<BlogPost> posts) {
mPosts = posts;
}
public List<BlogPost> getPosts() {
return mPosts;
}
public Set<String> getAllAuthors() {
Set<String> allAuthors = new TreeSet<String>();
for (BlogPost blogPost : posts) {
allAuthors.addAll(blogPost.getAuthor());
}
return allAuthors;
}
}
2 Answers
Yanuar Prakoso
15,196 PointsI try the challenge and pass it. This is the code I used to pass the challenge:
package com.example;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;
public class Blog {
List<BlogPost> mPosts;
public Blog(List<BlogPost> posts) {
mPosts = posts;
}
public List<BlogPost> getPosts() {
return mPosts;
}
public Set<String> getAllAuthors() {
Set<String> allAuthors = new TreeSet<>();
for (BlogPost blogPost : mPosts) {
allAuthors.add(blogPost.getAuthor());
}
return allAuthors;
}
}
Can you tell me what kind of error you are having?
Yanuar Prakoso
15,196 PointsHi There...
The problem is in your getAllAuthor method, as shown here:
public Set<String> getAllAuthors() {
Set<String> allAuthors = new TreeSet<String>();
for (BlogPost blogPost : posts) { //<-- this should be mPost not post
allAuthors.addAll(blogPost.getAuthor());//<-- change this to: allAuthors.add(blogPost.getAuthor), do not use addAll
}
return allAuthors;
}
I hope that can help you a little
Damjan Vlaic
19,244 Pointsit still gives me an error but tnx for helping ;)
Damjan Vlaic
19,244 PointsDamjan Vlaic
19,244 Pointsahha i didn't write for loop correctly like you did, now everythins is working, tnx man ;)