a java exception has occurred

package java;

import java.io.File;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.HashMap;
import java.util.Map;

import freemarker.template.Configuration;
import freemarker.template.ObjectWrapper;
import freemarker.template.Template;
import freemarker.template.TemplateException;

public class user {
public static void main(String[] args) throws IOException, TemplateException {
Configuration cfg=newConfiguration();
cfg.setDirectoryForTemplateLoading(new File("templates"));
cfg.setObjectWrapper(newDefaultObjectWrapper());

Map root=new HashMap();
root.put("ha","LD");



Template t1= cfg.getTemplate("a.ftl");


Writer out=new OutputStreamWriter(System.out);
t1.process(root,out);
out.flush();
out.close();
}

private static ObjectWrapper newDefaultObjectWrapper() {
// TODO Auto-generated method stub
return null;
}

private static Configuration newConfiguration() {
// TODO Auto-generated method stub
return null;
}
}



ftl文件中：#{ha}

运行输出时，弹出a java exception has occurred