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Using AST to parse my code with eclipse 3.2 [message #235877]

Thu, 14 September 2006 01:39

Eclipse User

Originally posted by: diegobt.gmail.com

Hi All:
I want to use Eclipses ASTParser to parse a .java and generate an AST to
print it.
After reading this
http://www-128.ibm.com/developerworks/opensource/library/os- ast/?ca=dgr-lnxw97ASTParser

I tried to get this snippet to do it.

File file = new File("ClassA.java");
BufferedReader in = new BufferedReader(new FileReader(file));
StringBuffer buffer = new StringBuffer();
String line = null;
while (null != (line = in.readLine())) {
buffer.append("\t" + line);
buffer.append("\n");
}

ASTParser parser = ASTParser.newParser(AST.JLS2);
parser.setKind(ASTParser.K_COMPILATION_UNIT);
String text = buffer.toString();
parser.setSource(text.toCharArray());
CompilationUnit node = (CompilationUnit) parser.createAST(null);
ASTVisitor visitor = new ASTPrintVisitor();
node.accept(visitor);

But I get this:

Exception in thread "main" java.lang.NoClassDefFoundError:
org/eclipse/core/runtime/Plugin
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at
java.security.SecureClassLoader.defineClass(SecureClassLoade r.java:124)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268 )
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319 )
at
org.eclipse.jdt.core.dom.ASTParser.initializeDefaults(ASTPar ser.java:230)
at org.eclipse.jdt.core.dom.ASTParser.<init>(ASTParser.java:212)
at org.eclipse.jdt.core.dom.ASTParser.newParser(ASTParser.java: 112)
at ASTPrint.main(ASTPrint.java:18)

I've been debugging it but cant figure out what to do. Perhaps someone
could help me out.
Thanks in advance!
/diego

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Re: Using AST to parse my code with eclipse 3.2 [message #235887 is a reply to message #235877]

Thu, 14 September 2006 08:37

Philippe Mulet

Messages: 229
Registered: July 2009

Senior Member

This error means you are running your code outside an instance of
running Eclipse (this is why the plugin layer isn't initialized).

This being said, since 3.2M6, we allow creating DOM ASTs outside Eclipse
with some limitation (no binding). Please check
https://bugs.eclipse.org/bugs/show_bug.cgi?id=87852 and see if you
deviate from the scenario supported there.

Diego Tiscornia wrote:
> Hi All:
> I want to use Eclipses ASTParser to parse a .java and generate an AST to
> print it.
> After reading this
> http://www-128.ibm.com/developerworks/opensource/library/os- ast/?ca=dgr-lnxw97ASTParser
>
>
> I tried to get this snippet to do it.
> File file = new File("ClassA.java");
> BufferedReader in = new BufferedReader(new FileReader(file));
> StringBuffer buffer = new StringBuffer();
> String line = null;
> while (null != (line = in.readLine())) {
> buffer.append("\t" + line);
> buffer.append("\n");
> }
>
> ASTParser parser = ASTParser.newParser(AST.JLS2);
> parser.setKind(ASTParser.K_COMPILATION_UNIT);
> String text = buffer.toString();
> parser.setSource(text.toCharArray());
> CompilationUnit node = (CompilationUnit) parser.createAST(null);
> ASTVisitor visitor = new ASTPrintVisitor();
> node.accept(visitor);
>
> But I get this:
> Exception in thread "main" java.lang.NoClassDefFoundError:
> org/eclipse/core/runtime/Plugin
> at java.lang.ClassLoader.defineClass1(Native Method)
> at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
> at
> java.security.SecureClassLoader.defineClass(SecureClassLoade r.java:124)
> at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
> at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
> at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
> at java.security.AccessController.doPrivileged(Native Method)
> at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
> at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
> at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268 )
> at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
> at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319 )
> at
> org.eclipse.jdt.core.dom.ASTParser.initializeDefaults(ASTPar ser.java:230)
> at org.eclipse.jdt.core.dom.ASTParser.<init>(ASTParser.java:212)
> at org.eclipse.jdt.core.dom.ASTParser.newParser(ASTParser.java: 112)
> at ASTPrint.main(ASTPrint.java:18)
>
> I've been debugging it but cant figure out what to do. Perhaps someone
> could help me out.
> Thanks in advance!
> /diego
>

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