Question

Define a class named Document that contains an instance variable of type String named text that stores any textual content for the document. Create a method named toString that returns the text field and also include a method to set this value.

Next, define a class for Email that is derived from Document and includes instance variables for the sender, recipient, and title of an email message. Implement appropriate set and get methods. The body of the email message should be stored in the inherited variable text. Redefine the toString method to concatenate all text fields.

Similarly, define a class for File that is derived from Document and includes an instance variable for the pathname. The textual contents of the file should be stored in the inherited variable text. Redefine the toString method to concatenate all text fields.

Finally, define a class DocumentTest that creates several sample objects of type Email and File in the main method. Test your objects by passing them to the following subroutine that returns true if the object contains the specified keyword in the text property. public static boolean ContainsKeyword(Document docObject, String keyword) { if (docObject.toString().indexOf(keyword,0) >= 0) return true ; return false ;

Answer 1

DocumentTest.java

import org.junit.Test;
import static org.junit.Assert.*;

public class DocumentTest {
  
    @Test
    public void canCreateDocumentObject() {
        Document document = new Document();
        assertNotNull(document);
    }
  
    @Test
    public void aDocumentHasTextContent() {
        Document document = new Document();
        document.setText("This is the text of the document");
        assertEquals("Text is", "This is the text of the document", document.toString());
    }
  
    @Test
    public void aDocumentCanLookIfAKeywordIsPresent() {
        Document document = new Document();
        document.setText("This is the text of the document");
        assertTrue(Document.ContainsKeyword(document, "of the document"));
      
        Email email = new Email();
        email.setText("I am starting a new job");
        assertFalse(Document.ContainsKeyword(email, "of the document"));
        assertTrue(Document.ContainsKeyword(email, "I am"));
      
        File file = new File();
        file.setText("");
        assertTrue(Document.ContainsKeyword(file, ""));
    }
}

Document.java

public class Document {
  
    private String text;
  
    public Document() {
      
    }
  
    public Document(String text) {
        this.text = text;
    }
  
    public void setText(String text) {
        this.text = text;
    }

    public String getText() {
        return text;
    }
  
    public static boolean ContainsKeyword(Document docObject, String keyword) {
        if(docObject.toString().indexOf(keyword, 0) >= 0 ) {
            return true;
        }
        return false;
    }
  
    @Override
    public String toString() {
        return text;
    }

    @Override
    public int hashCode() {
        int hash = 7;
        hash = 67 * hash + Objects.hashCode(this.text);
        return hash;
    }

    @Override
    public boolean equals(Object obj) {
        if(this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        final Document other = (Document) obj;
        if (!Objects.equals(this.text, other.text)) {
            return false;
        }
        return true;
    }
  
}

Email.java

public class Email extends Document {
    private String sender;
    private String recipient;
    private String title;

    public Email() {
        super();
    }

    public void setSender(String sender) {
        this.sender = sender;
    }

    public String getSender() {
        return sender;
    }

    public void setRecipient(String abchotmailcom) {
        this.recipient = abchotmailcom;
    }

    public String getRecipient() {
        return recipient;
    }

    public void setTitle(String starting_New_Job) {
        this.title = starting_New_Job;
    }

    public String getTitle() {
        return title;
    }
  
    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder();
        builder.append("Sender: ").append(getSender()).append("\n");
        builder.append("Recipient: ").append(getRecipient()).append("\n");
        builder.append("Title: ").append(getTitle()).append("\n");
        builder.append("Body: ").append(super.toString());
        return builder.toString();
    }
  
}

File.java

public class File extends Document {
    private String pathname;
  
    public File() {      
    }

    public void setPathname(String pathname) {
        this.pathname = pathname;
    }

    public String getPathname() {
        return pathname;
    }
  
    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder();
        builder.append("Path: ").append(getPathname()).append("\n");
        builder.append("Contents: ").append(super.toString());
        return builder.toString();
    }
}