问让Javac来接我的班

EN

import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.util.Arrays;
import java.util.Locale;
import java.util.logging.Logger;
import javax.tools.Diagnostic;
import javax.tools.DiagnosticCollector;
import javax.tools.JavaCompiler;
import javax.tools.DiagnosticCollector;
import javax.tools.JavaCompiler;    
import javax.tools.JavaCompiler.CompilationTask;
import javax.tools.JavaFileObject;
import javax.tools.SimpleJavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;

/**
* A test class to test dynamic compilation API.
*
*/
public class CompilerAPITest {
    static final Logger logger = Logger.getLogger(CompilerAPITest.class.getName()) ;

    public void doCompilation (){
        File[] files = {new File("/home/guestu/GeneratedClass.java")};

        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();

        StandardJavaFileManager stdFileManager = compiler.getStandardFileManager(null, Locale.getDefault(), null);
        /* Prepare a list of compilation units (java source code file objects) to input to  compilation task*/
        Iterable<? extends JavaFileObject> compilationUnits = stdFileManager.getJavaFileObjects(files);

        /*Create a diagnostic controller, which holds the compilation problems*/
        DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<>();
        /*Create a compilation task from compiler by passing in the required input objects prepared above*/
        CompilationTask compilerTask = compiler.getTask(null, stdFileManager, diagnostics, null, null, compilationUnits) ;

        boolean status = compilerTask.call();
        if (!status){//If compilation error occurs
            /*Iterate through each compilation problem and print it*/
            for (Diagnostic diagnostic : diagnostics.getDiagnostics()){
                System.out.format("Error on line %d in %s", diagnostic.getLineNumber(), diagnostic);
            } 
    }
    try {
       stdFileManager.close() ;//Close the file manager
    } catch (IOException e) {
 }

//Here is Helloworld.java
public class Helloworld extends GeneratedClass{
    public static void main(String[] args){
        System.out.println("Hello");

    }

}

//And here is GeneratedClass.java
package com.sun.tools.javac.parser;

import com.sun.tools.javac.tree.JCTree;
import com.sun.tools.javac.code.Flags;
import com.sun.tools.javac.tree.TreeMaker;
import com.sun.tools.javac.tree.JCTree.JCAnnotation;
import com.sun.tools.javac.tree.JCTree.JCClassDecl;
import com.sun.tools.javac.tree.JCTree.JCCompilationUnit;
import com.sun.tools.javac.tree.JCTree.JCExpression;
import com.sun.tools.javac.tree.JCTree.JCModifiers;
import com.sun.tools.javac.tree.JCTree.JCTypeParameter;
import com.sun.tools.javac.util.List;
import com.sun.tools.javac.util.ListBuffer;
import com.sun.tools.javac.util.Name;
import com.sun.tools.javac.util.Names;

/* This class programmatically produces the superclass "GeneratedClass" with signature public class GeneratedClass{} */

public class GeneratedClass {
    TreeMaker maker;
    Names names;
    public GeneratedClass(ParserFactory fac) {
        maker = fac. F;
        names = fac.names;
    }

    public JCCompilationUnit getTree() {
        ListBuffer<JCTree> defs = new ListBuffer<JCTree>();
        defs.append(makeClassDecl());
        return maker.TopLevel(List.<JCAnnotation>nil(), null, defs.toList());
    }

    /* This is a class decalaration node for public class GeneratedClass{}*/
    protected JCClassDecl makeClassDecl() {
        JCModifiers mods = maker.Modifiers(Flags.PUBLIC);
        Name name = names.fromString("GeneratedClass");
        return maker.ClassDef(mods, name, List.<JCTypeParameter>nil(), null, List.<JCExpression>nil(), List.<JCTree>nil());
    }
}