getting IllegalArgumentException when trying to create key for entity

Question

I'm working on Google App Engine and I'm stuck at a point. I'm trying to create a key for my entity. Here is the code: ``` Element child = (Element) itr.next(); String name = ""; if(child.getQualifiedName().equals("name")){ name += child.getText(); } Key drugKey = KeyFactory.createKey("DrugTarget", name); ``` I'm 100% sure that child.getText() doesn't return null. I tested it already. I have another piece of code that creating Key works perfectly. Both seem similar to each other. ``` String drug = req.getParameter("drugname"); Key drugKey = KeyFactory.createKey("DrugTarget", drug); ``` I really did'nt understand why it gives error. First piece of code is belonged to a Java Class and I call this class in a Java Servlet Class. The second one is belonged to a Java Servlet Class. But I think the problem is different. Could you please help? Thanks. Edited Part: ``` if(child.getQualifiedName().equals("name")){ if(child.getText() != null){ name = child.getText(); } else{ name = "asd"; } } ``…

Accepted Answer

The error message said:

```
Uncaught exception from servlet
java.lang.IllegalArgumentException: name cannot be null or empty
```

And your actual code:

```
String name = "";
if(child.getQualifiedName().equals("name")){
  name += child.getText();
}
Key drugKey = KeyFactory.createKey("DrugTarget", name);
```

So in the if statement the `child.getQualifiedName().equals("name")` expression is false, and the 'name' String variable is still an empty String (`String name = ""`). And that is what the error message said: cannot be an empty String at `Key drugKey = KeyFactory.createKey("DrugTarget", name);` as parameter.

EDIT: Try out this:

```
Element child = (Element) itr.next();
String name = "defaultName";
if(child.getQualifiedName().equals("name")){
  name = child.getText();
}
Key drugKey = KeyFactory.createKey("DrugTarget", name);
```

The problem isn't that the `child.getText()` return with null or not, the problem is the expression at your if statement will be `false`, so the `name += child.getText();` is unreachable and the `name` still an empty String.

```
if(child.getQualifiedName().equals("name")){
      name += child.getText();
}
```

getting IllegalArgumentException when trying to create key for entity

Solution

Problem