rapid7/metasploit-framework

// Based on the example from http://www.java2s.com/Code/Java/JDK-6/CompilingfromMemory.htm

package javaCompile;

import java.net.URI;
import java.util.Arrays;
import java.util.List;
import java.util.ArrayList;
import java.lang.String;

import javax.tools.JavaCompiler;
import javax.tools.JavaFileObject;
import javax.tools.SimpleJavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;
import javax.tools.JavaFileObject.Kind;

public class CompileSourceInMemory {

    public static boolean CompileFromMemory(String strClass, String strCodeContent) {
        String[] classNames    = { strClass };
        String[] codeContent     = { strCodeContent };
        return CompileFromMemory(classNames, codeContent, null);
    }

    public static boolean CompileFromMemory(String[] classNames, String[] codeContent) {
        return CompileFromMemory(classNames, codeContent, null);
    }

    public static boolean CompileFromMemory(String[] classNames, String[] codeContent, String[] compOptions) {
        
        List<String> compOptList = null;
        if (compOptions != null) { compOptList = Arrays.asList(compOptions); }
        
        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();

        // Need to add a check that classNames.length == codeContent.length, else we're fubared.
        List<JavaFileObject> files = new ArrayList<JavaFileObject> () ;
        int i = 0;
        for (String codePage : codeContent) {
            files.add(new JavaSourceFromString(classNames[i], codePage));
            i++;
        }

        Iterable<? extends JavaFileObject> compilationUnits = files;
        
        JavaCompiler.CompilationTask task = compiler.getTask(null, null, null, compOptList, null, compilationUnits);
        
        boolean success = task.call();

        return success;

    }
}

class JavaSourceFromString extends SimpleJavaFileObject {
    final String code;

    JavaSourceFromString(String name, String code) {
        super(URI.create("string:///" + name.replace('.','/') + Kind.SOURCE.extension),Kind.SOURCE);
        this.code = code;
    }

    @Override
    public CharSequence getCharContent(boolean ignoreEncodingErrors) {
        return code;
    }
}