ArrayList is Picking Up Last Item During Iteration.

[James Dekker]

I created a simple web service which consists of a Person class containing a List of Car classes.

Person class:

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class Person {
	private String lastName;
	private String firstName;	
	private List<Car> cars;
	
	// Getters & Setters 
}

Car class:

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class Car {
	private String year;
	private String make;
	private String model;
	
	// Getters & Setters
}

Created a different object to store my inquries.

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class ResponseOutput {
	
	private String year;
	private String make;
	private String model;
	
	// Getter and Setters
}

Here's my actual client (a Jersey based Restful Web Service):

@Path("")
public class MyWebService {

	@GET
	@Path("showPerson")
	@Produces(MediaType.APPLICATION_JSON)
	public Person getPerson {
		Person person = new Person();
		person.setFirstName = "John";
		person.setLastName = "Doe";
		
		Car car1 = new Car();
		car1.setYear("2012");
		car1.setMake("Toyota");
		car1.setModel("Corolla");
		
		Car car2 = new Car();
		car2.setYear("2011");
		car2.setMake("Ford");
		car2.setModel("Focus");
	
		List<Car> cars = new ArrayList<Car>();
		cars.add(car1);
		cars.add(car2);
		
		person.setCars(cars);
		return person;
	}
	
	@GET
	@Path("{name}")
	@Produces(MediaType.APPLICATION_JSON) 
	public ResponseOutput getCar(@PathParam("name") String name) 
	{
		ResponseOutput output = new ResponseOutput();
		Person person = getPerson();
		
		List<Car> cars = person.getCars();
		
		for (Car car : cars) {
			
			if (name.equals(car.getMake())); {
			    System.out.println("\n\tcar.getMake(): " + "\n");
				output.setMake(car.getMake());
			}			
		}
		return output;
	}
}

When I call the getPerson() method as follows:

curl -X GET http://localhost:8080/myapp/showPerson

It returns a 201 containing this JSON Object (which is what I want):

{"cars":[{"make":"Toyota","model":"Corolla","year":"2012"},{"make":"Ford","model":"Focus","year":"2011"}],"firstName":"John","lastName":"Doe"}

However, when I call the getCar method() as follows:

curl -X GET http://localhost:8080/myapp/toyota

I get the following JSON object (with the second item in the ArrayList being added!):

{ "make":"Ford", "model":"null", "year":"null" }

I wanted it to be Toyota instead of Ford.

If you can tell, I printed out the value of the car.getMake() String and inside the console / shell, it ways says this:

car.getMake(): Toyota

car.getMake(): Ford

So, it seems that its iterating through the list but adding the last item (or just next item)??

What am I possibly doing wrong? Thank you for taking the time to read this...

[Suresh Sajja]

James Dekker wrote:

     if (name.equals(car.getMake())); {
          System.out.println("\n\tcar.getMake(): " + "\n");
          output.setMake(car.getMake());
     }			
		

1. If loop is not coded correctly. semicolon is added at the end of if condition.
by doing so, if condition is evaluated and does nothing. and the next two lines are executed for all cars irrespective of if result.
2. you may have to call "name.equalsIgnoreCase(car.getMake)"

If you can tell, I printed out the value of the car.getMake() String and inside the console / shell, it ways says this:

car.getMake(): Toyota

car.getMake(): Corolla // I assume you meant Ford here

[James Dekker]

Thanks for responding, Suresh!

Yes, I meant "Ford" instead of "Corolla" and even edited my original post to reflect that.

    
 if (name.equals(car.getMake())); {
     System.out.println("\n\tcar.getMake(): " + "\n");
      output.setMake(car.getMake());
}		

1. If loop is not coded correctly. semicolon is added at the end of if condition.
by doing so, if condition is evaluated and does nothing. and the next two lines are executed for all cars irrespective of if result.

2. you may have to call "name.equalsIgnoreCase(car.getMake)"

1. Can you elaborate on this? I think Eclipse might have added this (the ";") in... This does look odd... Should the semicolon be removed?
It does seem like the conditional "if" isn't picking up or getting invoked properly because both cars are printed to the console.

2. Will try your suggestion with the "name.ignoreCase(car.getMake)"

With thanks!

[Jan Hoppmann]

James Dekker wrote:
1. Can you elaborate on this? I think Eclipse might have added this (the ";") in... This does look odd... Should the semicolon be removed?
It does seem like the conditional "if" isn't picking up or getting invoked properly because both cars are printed to the console.

In Java, a semicolon ends a statement. So your program evaluates the if, but there is nothing it does afterwards (because of the ;, which is basically an empty statement on the same line). You should remove it, yes.

[James Dekker]

Jan & Suresh,

Thank you! The semicolon was the thing that was breaking my code.

Good eyes! Can't believe I missed that.