How can I convert a string to an object or class

Question

I would like to read a file representing a class, and convert it to an object or a class (object preferred). Other postings suggest using javax.tools.JavaCompiler to convert from a string but then say that this is not always available (posting on 1 Jan 09). If this is still not universally available is there another way to do this? If this is not available, are there any examples of how it should be done?
My understanding from what I've read is to read the file into a String then compile the String using javax.tools.JavaCompiler, which is an Interface.
thanks

Answer 1

skidmarks wrote:
What i would like to do is to take a Java file representing a class and compile it at runtime. However, the comment about a JDK being available at runtime makes this unattractive.So, you want to compile .java files, but you don't want to have to use a compiler?
The next guess would to be to create a .jar file and reference it at runtime. Here's the scenario:Eh? How is that even remotely equivalent?
1. People using the 'system' will have a varied knowledge of Java.
2. My hope was to require that anyone using the program would only need to create a Java Class file,You mean a Java source file. You have said that YOU want to create the .class file. If they are creating the .class file, then all you need to do is load it with a ClassLoader and start using it.
You might try clarifying your requirements a bit.
In either case, the Class Files would look like:
public class Name {
int field1;
float field2;
} With all the field types being simple Java Primitives.What is the point of this? What are you ultimately trying to accomplish, that can be served by user-defined groups of primitives, with no complex object graphs and no user-defined methods?
Depending on what you're really getting at, using scripting features via beanshell, groovy, or javascript might be an approach to consider, or using Scala to produce a domain-specific language (although I suspect that last may be overkill, and beyond your current skill level).
If this is so, is there any way to create a .jar file at runtime? Do I have to exec("jar") or is there another way.A .jar file is just a .zip file with a manifest. Look at the java.util.jar package. But note that creating a .jar file has nothing to do with the rest of what you're asking about.