从现有的Java程序编译并创建新的Java程序的实例

Question

I am writing a java program in eclipse to extract forms from lotusnotes db. Whenever I get a form I need to create a .java file containng a class with same name as of form. Then I have to compile this new .java class which gives me .class file & hence I can create an instance of that new class. I need to know whether this approach of creating,compiling & instantiating a new class is possible from a single existing java program.

My pseudocode goes below

import java.util.Iterator;
import de.bea.domingo.*;
import java.util.List;
import java.io.*;
public class LotusNotesDBExtraction
{
public static void main(String[] args) throws DNotesException,IOException
{
    DNotesFactory factory = DNotesFactory.getInstance();
    DSession session = factory.getSession();
    DDatabase database = session.getDatabase("", "employee.nsf");
    List formlist=database.getForms();
    //System.out.println("Number of forms are :"+formlist.size());
    for(int i=0;i<formlist.size();i++)
    {
        DForm formn=(DForm)(formlist.get(i));
        DForm formname= database.getForm(formn.getName());

        **//Creating a class in a file
        FileWriter outputfile = new FileWriter("D:\\Lotusnotesformfiles\\"+formn.getName()+".java",true);
        BufferedWriter out = new BufferedWriter(outputfile);
        out.write("public class "+formn.getName()+" {");
        out.newLine();
        out.flush();**

        try
        {
             **//Compile the class here**   
                            Process p1 = Runtime.getRuntime().exec("cmd javac \"D:\\Lotusnotesformfiles\\"+formn.getName()+".java\"");   
            System.out.println("compiled");
         }   
          catch(IOException x)
        {
            x.printStackTrace();
        }
                **//instantiate the new class here**
}
}

But I am not able to get .class file for the new class. Can I instantiate the new class in the same program?? I was stuck at this point. Can any please help me

Answer 1

您应该能够使用Reflection API进行很多（如果不是全部）操作，它允许您在运行时修改类，检查类的内容，甚至动态加载类（例如，在编译后）。