Collection specific elements not generic problem

[Rahul Shilpakar]

Hello Ranchers,

I am facing an error which is giving me a problem. I google it but it couldn't help.
I am running the Eclipse Europa on Windows vista with jdk & jre 1.6.
All the things works fine except:

Problem::

Following is my code:

 public class Ba {
 
public static void main(String[] args) {

// LINE 1List[B]<String>[/B] li = new ArrayList[B]<String>[/B]();
String a = "Hello";
String b = "World";
li.add(a);
li.add(b);
}
}   

I wanted to add only String values in the List not other type of values.
But,

It gives me compilation error at LINE 1 at the point of

 [B]<String>[/B]   

.

ERROR::
Exception in thread "main" java.lang.Error: Unresolved compilation problems:
Syntax error on token "<", invalid AssignmentOperator
Syntax error on token "=", != expected
Syntax error on token "<", ( expected
Syntax error on token "(", invalid Expression

at Ba.main(Ba.java:22)


When i use plain code like

   List li = new ArrayList();
 

When i use above line code it works fine.


What shall i have to do get rid of it. Because of this my whole developed project which i already done on Windows XP platform getting messed up.

Thanks in advance.

[Jeanne Boyarsky]

Rahul,
It looks like you are compiling with an earlier version of Java. Can you confirm your project is using Java 1.4 in Eclipse?

This sounds like a tooling problem so I'll move it to our IDEs forum.

[Rahul Shilpakar]

Originally posted by Jeanne Boyarsky:
It looks like you are compiling with an earlier version of Java. Can you confirm your project is using Java 1.4 in Eclipse?

I once again checked the version of the java by firing command
java -version in command prompt
and it shows java 1.6.0_04 version

Thanks again

[Campbell Ritchie]

What you have on command prompt and what you are using in Eclipse can be two very different things. Get the properties for the project you are working in on Eclipse, that might be using Java 1.4 compatibility.

[Jeanne Boyarsky]

You might need to check in two places. The preferences for the Java project itself. And if it says "use defaults", you need to check the workspace preferences too.

[Rahul Shilpakar]

Friends sorry in advance to ask you a simple question again

How can i see which JDK version i am using in Eclipse?

As you suggested i saw the settings in the Preference menu OR in Project properties
And i found jre 1.6 only in the Library tab of the Java Build Path.

Thank you.

[Jeanne Boyarsky]

Originally posted by Rahul Shilpakar:
How can i see which JDK version i am using in Eclipse?

In the project preferences, go to the "java compiler" option. If "enable project specific settings" is checked, the version # is specified here. If the checkbox is not selected, the version # is in the workspace preferences under java --> compiler. These settings move around a bit in different versions of Eclipse - these locations are for Eclipse 3.3. They were nearby on prior versions, so you should see them in a similar location.

Note that the jar under the build path might not be the version of Java you are using. It's possible to compile against older versions of Java on a newer JVM.

[Rahul Shilpakar]

Yes, You are right Jeanne Boyarsky.

Its compiling with older version (i.e. 1.4) of the JDK.

Now, what am i suppose to do so that my Java code will get compile with latest version (i.e. 1.6) of JDK which i already installed on my mahcine ?

Thank you.

[Rahul Shilpakar]

Sorry for one incorrect information:

Earlier i mentioned that i am using Eclipse europa.
BUT, i am sorry.

I am using Eclipse 3.0 version.

[Jeanne Boyarsky]

Rahul,
I don't believe Eclipse 3.0 supports Java 5. You'll need to upgrade to a later version of Eclipse to use the Java 5 features.

[Ilja Preuss]

Originally posted by Rahul Shilpakar:

Now, what am i suppose to do so that my Java code will get compile with latest version (i.e. 1.6) of JDK which i already installed on my mahcine ?

Eclipse likely *is* already using your JDK. It is *never* using the compiler that is coming with the JDK, but uses its own one. So, to configure Eclipse to compile 1.6 code, you need to *both* point it to the right JDK *and* tell the *eclipse compiler* to act 1.6 compliant.

[Rahul Shilpakar]

originally posted by : Ilja Preuss
you need to *both* point it to the right JDK *and* tell the *eclipse compiler* to act 1.6 compliant.

how can i do that? I mean what are the steps to do that?

Thanks

[Ilja Preuss]

Originally posted by Rahul Shilpakar:


how can i do that? I mean what are the steps to do that?

Thanks

The steps that Jeanne already provided.

[Tim Holloway]

There's also one more step, and it's very important. You have to actually install the desired JVM into Eclipse. On the Window/Preferences dialog, select Java/Installed JRE's, click the "Add" button and select the directory of the JVM you want to add. You can then select it as the default JVM for the workspace or as a selected JVM for a project.

As to whether or not Eclipse actually uses that compiler for workspace compiling, there seems to be some confusion. Allegedly Eclipse has its own compiler that's gimmicked up to integrate more closely with the IDE and the JRE is actually literally that - a JRE, not a JDK: used by the debugging phase.

As far as I can remember, Eclipse 3.0 supported Java 5, but not Java 6.

[Rahul Shilpakar]

Orginally posted by Tim Holloway
As far as I can remember, Eclipse 3.0 supported Java 5, but not Java 6.

Yes, I tried all the things as said above.
And it does not support with JDK 6.Better i will change Eclipse.

Thanks all.