Eclipse not compiling my Java file

[Valliy]

Can anyone tell me why my eclipse so with the experiment to compile my code..?? I always get this message :

Exception in thread "main" java.lang.Error: Unresolved compilation problems: 
The type ArrayList is not generic; it cannot be parameterized with arguments <Integer> 
Syntax error, parameterized types are only available if source level is 5.0 
The type ArrayList is not generic; it cannot be parameterized with arguments <Integer> 
Syntax error, parameterized types are only available if source level is 5.0

I am hoping that some members over there should be knowing some solutions for this.!! Please help me as soon as possible.

[Ackley]

The type ArrayList is not generic, it can not be parameterized with arguments <Integer>
Syntax error, parameterized types are only available if source level is 5.0

You should still uses Java 1.4, but according to the task and, above all, for your own well-being on Java 1.5 upgrade. I am sure that updating your application will definitely help you.!!

[pancham]

In Java 1.4, there is only untyped lists: one can poke objects of any type and must at always cast to the desired type "," where a lot of funny mistakes can occur, if not all objects in the list of the same type. So even I would like to recommend you to update your Java application. If you want some more help regarding the Eclipse for your Java Application, you can see here.

[PARRISH]

You can check the following example :

List strings = new LinkedList(); 
strings.add("Lama");
strings.add("Duck");
strings.add(new Integer(0xCAFE));

Iterator it = strings.iterator(); 
while(it.hasNext()) { 
String animal = (String)it.next(); 
System.out.println(animal); 
}

The above code will compile correctly, the duration of the loop but in a ClassCastException thrown when it.next () instead of the string-awaited returns the integer, which we have inserted last in the list. Would not it be nice if you could tell the compiler that should only contain a list of objects of a certain type, so that such errors are detected already during programming?

[RichiRich]

I would like to comment on coding given by the "PARRISH". The same code can be much more concisely written and type-safe, especially if you Generics, uses a new feature in Java 1.5. This can already be set at compile time, which types are allowed in a list, that is, the compiler will not allow inserting invalid types (known as "parameterized types"):

List<String> strings = new LinkedList<String>();
strings.add("Lama"); // ok 
strings.add("Duck"); // ok 
strings.add(new Integer(0xCAFE));

for(String animal : strings) 
{ 
Element in the list "strings" 
System.out.println(animal); 
}

The above code will not compile because of the attempt to insert an integer in the list, but you can at runtime be 100% sure that the list really just strings. The loop is also freed from Typcasts and can be transferred to another new 1.5 feature (enhanced for) written more elegant without iterator.