Code challenge is confusing me

Question

I cannot figure out exactly what he's trying to get us to do. It almost seems like he wants us to do the same things as the gifs but in order to create the findById type function it seems that you need to have something to loop through like how we had that gifRespository in the class. But we don't have an option or way to really create it.

com/teamtreehouse/contactmgr/controller/ContactController.java

package com.teamtreehouse.contactmgr.controller;

import com.teamtreehouse.contactmgr.model.Contact;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.ui.ModelMap;

@Controller
public class ContactController {
    @RequestMapping("/")
    public String home() {
      return "index";
    }

    @RequestMapping("/contact")
    public String contact(ModelMap modelMap) {
      Contact c = new Contact();
      modelMap.put("contact",c);
      return "contact_detail";
    }
}

com/teamtreehouse/contactmgr/model/Contact.java

package com.teamtreehouse.contactmgr.model;

public class Contact {
  private int id;
  private String firstName;
  private String lastName;
  private String email;

  public Contact() {}

  public Contact(int id, String firstName, String lastName, String email) {
    this.id = id;
    this.firstName = firstName;
    this.lastName = lastName;
    this.email = email;
  }

  public int getId() {
    return id;  
  }

  public String getFirstName() {
    return firstName;  
  }

  public String getLastName() {
    return lastName;  
  }

  public String getEmail() {
    return email;  
  }

  public void setId(int id) {
    this.id = id;  
  }

  public void setFirstName(String firstName) {
    this.firstName = firstName;  
  }

  public void setLastName(String lastName) {
    this.lastName = lastName;  
  }

  public void setEmail(String email) {
    this.email = email;
  }
}

Answer 1 · 2016-02-02T23:14:04Z

February 2, 2016 11:14pm

Hello, I was confused on this one as well when I first took it, it's actually a lot simpler than what I thought it was, the first thing we want to do is add in the variable as a path variable, both in the constructor and the mapping request,

so it'd be something like

@RequestMapping("/contact/{id}")

Then be sure to add the path variable into the argument for the method using the PathVariable Object that we've previously used.

Then all that we are doing is passing in the value id into the parameters for the method, you still have to pass in the other string values that the constructor in your Conctact expects, but you may call them whatever you would like.

Everything else looks good.

Answer 2 · 2018-01-09T17:56:49Z

January 9, 2018 5:56pm

This one worked for me:

package com.teamtreehouse.contactmgr.controller;

import com.teamtreehouse.contactmgr.model.Contact;

import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.ui.ModelMap;

@Controller public class ContactController { @RequestMapping("/") public String home() { return "index"; }

@RequestMapping("/contact") public String contactController(ModelMap modelMap) { Contact contact = new Contact(12, "one", "two", "three@four"); modelMap.put("contact", contact); return "contact_detail"; }

}

Answer 3 · 2016-02-15T22:12:52Z

February 15, 2016 10:12pm

What's wrong with this, i really don't get it !?

@RequestMapping("/contact/{id}")
public String contactDetail(@PathVariable int id, ModelMap modelMap) {
     Contact c = new Contact(12, "Max","Musterman","musterman@email.com");
     modelMap.put("contact", c);
     return "contact_detail";
 }

Answer 4 · 2016-02-16T06:35:27Z

February 16, 2016 6:35am

Hi Rob,

At last you've decided to provide some English language clarity

(replace hard coded '12' with int variable),

which pointed me (and hopefully Jens) towards this code:

@RequestMapping("/contact/{id}")
public String contactDetail(@PathVariable int id, ModelMap modelMap) {
     Contact c = new Contact(id, "Max","Musterman","musterman@email.com");
     modelMap.put("contact", c);
     return "contact_detail";
 }

Answer 5 · 2016-02-11T06:14:23Z

February 11, 2016 6:14am

Hi Justin I understand that this is confusing, I'll see if I can explain better. Our contact item takes about 4 paraetets, one being an int and 3 being a string. So to pass the variable that we mapped into the constructor would look something like.

Contact contact = new Contact(id, "","","")

Changing the strings to whatever value that we want all that this challenge expects is to use the int value that we mapped when we create a new contCt object,

The course is new so we won't see a lot of questions about this but just keep doing what you're doing and we'll help you work out anything else needed.

Answer 6 · 2016-02-06T04:42:32Z

February 6, 2016 4:42am

Rob's answer totally confused me...

Adding the suggested @Request line by itself just gives 3 compiler errors.

I try to google the following statement and don't get any relevant code samples:

"then once we have these two set up we can pass in the PathVariable (which we should be calling id) into the constructor. "

Just reading this statement over and over I get no hint at all

as to what type of code is needed to answer the challenge question.

So I went back to the video and at time index 02:43 there is some code like:

@PathVariable String name

...so maybe transposing "id" for name, means using something like:

@PathVariable String id

So I tried this:

    @RequestMapping("/contact/{id}")
    public String contact(@PathVariable String  id, ModelMap modelMap) {

    }

And it came up with a compiler error about missing return

so I changed the code to this:

    @RequestMapping("/contact/{id}")
    public String contact(@PathVariable String  id, ModelMap modelMap) {
    return "contactID"; 
    }

this gives the Bummer:

Bummer! Are you sure that you returned the correct view name?

Have no idea what "view name" it wants, so stopped there.

Answer 7 · 2016-02-11T02:52:09Z

February 11, 2016 2:52am

Hi Rob,

It sounds like you are saying I'm on the right track (which is encouraging), but

"pass the id into the parameter in the constructor for contact, as well as the strings that it takes."

..sounds to me like:

Οἱ δὲ Φοίνιϰες οὗτοι οἱ σὺν Κάδμῳ ἀπιϰόμενοι.. ἐσήγαγον διδασϰάλια ἐς τοὺς ῞Ελληνας ϰαὶ δὴ ϰαὶ γράμματα, οὐϰ ἐόντα πρὶν ῞Ελλησι ὡς ἐμοὶ δοϰέειν, πρῶτα μὲν τοῖσι ϰαὶ ἅπαντες χρέωνται Φοίνιϰες· μετὰ δὲ χρόνου προβαίνοντος ἅμα τῇ ϕωνῇ μετέβαλον ϰαὶ τὸν ϱυϑμὸν τῶν γραμμάτων. Περιοίϰεον δέ σϕεας τὰ πολλὰ τῶν χώρων τοῦτον τὸν χρόνον ῾Ελλήνων ῎Ιωνες· οἳ παραλαβόντες διδαχῇ παρὰ τῶν Φοινίϰων τὰ γράμματα, μεταρρυϑμίσαντές σϕεων ὀλίγα ἐχρέωντο, χρεώμενοι δὲ ἐϕάτισαν, ὥσπερ ϰαὶ τὸ δίϰαιον ἔϕερε ἐσαγαγόντων Φοινίϰων ἐς τὴν ῾Ελλάδα, ϕοινιϰήια ϰεϰλῆσϑαι.

That is - it's all Greek to me what you are saying (and your answer doesn't really explain the "view name" error I got).

So right now I'm researching the Thymeleaf documentation and any samples I can find scattered through the internet to see if I can find enough samples to detect the pattern of what is going on with the code.

But googling for "Spring Thymeleaf example" brings up 73,700 results --it could be a while to get through all of them...

By the way this is the only forum thread for this URI challenge

https://teamtreehouse.com/community/code-challenge:11292

...in the "7922" ("Modeling, Storing, and Presenting Data") forum section for this course:

https://teamtreehouse.com/community/stage:7922

Also..it's interesting that I don't see any Treehouse forum threads for the challenges in the final section of the course "Using the MVC Architecture" when I look under all forum threads for Spring Basics:

https://teamtreehouse.com/community/syllabus:1992

That says to me either:

1.) The final section is so much easier then the ("Modeling, Storing, and Presenting Data") forum section

that no questions need be asked (unlikely),

OR

2.) Not a whole lot of people (except the very smartest who don't need to ask questions) have gotten past the Modeling, Storing, and Presenting Data challenges (and most are therefore probably "stuck" in that middle section of challenges).

In the final "Using the MVC Architecture" section, there are three "Fix" challenges --I got through the first one, but I'm stuck on the last two (they are cumulative and sequential in building one set of code atop another).

So I'm also hoping (long term) that once enough people become "unstuck" on the M.S.P.D. challenges it will break any "logjam" potentially restricting questions on the last two challenges for the course.

Personally I don't like to throw up too many threads at once - especially for courses that deal with subject matter that has never been part of a treehouse course before (Thymeleaf views).

A google search for "treehouse thymeleaf" shows that at least 3 people have gotten "achievements" for completing the course:

CJ Marchione, Saleh Jarad, and kouroshraeen

Maybe one of them will stop by to share their insights...

Answer 8 · 2016-02-16T10:12:57Z

February 16, 2016 10:12am

no not working, is there a special connotation to it, like {} ? by the way this line was missing: import org.springframework.web.bind.annotation.PathVariable; but still doesn't work.....

Answer 9 · 2017-10-16T16:12:39Z

October 16, 2017 4:12pm

@RequestMapping("/contact/{id}") public String contact(@PathVariable int id, ModelMap modelMap) { Contact c = new Contact(id ,"","",""); modelMap.put("contact",c); return "contact_detail"; }

Welcome to the Treehouse Community

Looking to learn something new?

missgeekbunny

missgeekbunny

Code challenge is confusing me

9 Answers

Rob Bridges

Rob Bridges

missgeekbunny

missgeekbunny

Rob Bridges

Rob Bridges

missgeekbunny

missgeekbunny

missgeekbunny

missgeekbunny

Justan Human

Justan Human

Rob Bridges

Rob Bridges

Vladimir Hisamutdinovs

Vladimir Hisamutdinovs

Unsubscribed User

Unsubscribed User

Rob Bridges

Rob Bridges

james white

james white

Unsubscribed User

Unsubscribed User

Rob Bridges

Rob Bridges

james white

james white

Rob Bridges

Rob Bridges

james white

james white

Unsubscribed User

Unsubscribed User

Unsubscribed User

Unsubscribed User

Robert eRS

Robert eRS