Runtime error using the Eclipse Abstract Syntax Tree

问题

I'm trying to use AST parser in a non-plugin environment. The code compiles, but I get the following runtime error:

Exception in thread "main" java.lang.NoClassDefFoundError: org/eclipse/core/resources/IResource at org.eclipse.jdt.core.dom.ASTParser.(ASTParser.java:189) at org.eclipse.jdt.core.dom.ASTParser.newParser(ASTParser.java: 118)

Here is the code I'm running:

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.jdt.core.dom.*;

public class TestAST
{

private void runTest()
{
    String helloStr ="\n"+
    "public class HelloWorld {\n"+
    "\n"+
    "   private String name=\"\"\n\n"+
    "   /**\n"+
    "    * \n"+
    "    */\n"+
    "    public void sayHello() {\n"+
    "    System.out.println(\"Hello \"+name+\"!\");\n"+
    "    }\n"+
    "\n"+
    "}";

    ASTParser parser = ASTParser.newParser(AST.JLS3); 
    parser.setKind(ASTParser.K_COMPILATION_UNIT);
    parser.setSource(helloStr.toCharArray());
    parser.setResolveBindings(true);
    ASTNode tree = parser.createAST(null);
    tree.toString();

}

public static void main(String args[])
{
    TestAST ast = new TestAST();
    ast.runTest();
}
}

Does anyone know why this is happening?

Thanks in advance,

Shirley

回答1:

The IResource class is not on your classpath when you start the application.

If you're not using Eclipse (or some other tool) to manage the dependencies, you're going to have to track down every jar file that the Abstract Syntax Tree classes require and manually include them on your classpath. I'm not sure exactly how many this might be, but Eclipse is made up of many dozens of plugins, and manually working out the build dependencies will be a chore.

Edit: To add IResorce to the classpath, the particular jar file you're looking for will be called something like org.eclipse.core.resources_3.5.0.v20090512.jar, depending on your version of Eclipse. But I don't think it will be the only one you'll need...

回答2:

I recently ran into a similar issue and I slowly stepped through fixing one dependency at a time and here is the list of required dependencies that I came up with. I hope this saves some time for people who try to do this same task:

List (which matches picture below):

ContentType (org.eclipse.core.contenttype)
Jobs (org.eclipse.core.jobs)
Resources (org.eclipse.core.resources)
Runtime (org.eclipse.core.runtime)
Equinox Common (org.eclipse.equinox.common)
Equinox Preferences (org.eclipse.equinox.preferences)
JDT (org.eclipse.jdt)
JDT Core (org.eclipse.jdt.core)
OSGI (org.eclipse.osgi)
OSGI Services (org.eclipse.osgi.services)
OSGI Util (org.eclipse.osgi.util)

All these JARs will likely already be contained in your Eclipse plugins directory and you can find and add them to the build path by adding them as external JARs.

回答3:

I had the same problem. I solved adding the jars into the required dependencies of the the plugin.xml. You can find it in the tab Dependencies of the plugin.xml file.

来源：https://stackoverflow.com/questions/1903930/runtime-error-using-the-eclipse-abstract-syntax-tree

标签

java

eclipse-jdt