private void listBeans(JsonGenerator jg, ObjectName qry, String attribute,
      HttpServletResponse response)
  throws IOException {
    LOG.debug("Listing beans for "+qry);
    Set<ObjectName> names = null;
    names = mBeanServer.queryNames(qry, null);

    jg.writeArrayFieldStart("beans");
    Iterator<ObjectName> it = names.iterator();
    while (it.hasNext()) {
      ObjectName oname = it.next();
      MBeanInfo minfo;
      String code = "";
      Object attributeinfo = null;
      try {
        minfo = mBeanServer.getMBeanInfo(oname);
        code = minfo.getClassName();
        String prs = "";
        try {
          if ("org.apache.commons.modeler.BaseModelMBean".equals(code)) {
            prs = "modelerType";
            code = (String) mBeanServer.getAttribute(oname, prs);
          }
          if (attribute!=null) {
            prs = attribute;
            attributeinfo = mBeanServer.getAttribute(oname, prs);
          }
        } catch (AttributeNotFoundException e) {
          // If the modelerType attribute was not found, the class name is used
          // instead.
          LOG.error("getting attribute " + prs + " of " + oname
              + " threw an exception", e);
        } catch (MBeanException e) {
          // The code inside the attribute getter threw an exception so log it,
          // and fall back on the class name
          LOG.error("getting attribute " + prs + " of " + oname
              + " threw an exception", e);
        } catch (RuntimeException e) {
          // For some reason even with an MBeanException available to them
          // Runtime exceptions can still find their way through, so treat them
          // the same as MBeanException
          LOG.error("getting attribute " + prs + " of " + oname
              + " threw an exception", e);
        } catch ( ReflectionException e ) {
          // This happens when the code inside the JMX bean (setter?? from the
          // java docs) threw an exception, so log it and fall back on the
          // class name
          LOG.error("getting attribute " + prs + " of " + oname
              + " threw an exception", e);
        }
      } catch (InstanceNotFoundException e) {
        //Ignored for some reason the bean was not found so don't output it
        continue;
      } catch ( IntrospectionException e ) {
        // This is an internal error, something odd happened with reflection so
        // log it and don't output the bean.
        LOG.error("Problem while trying to process JMX query: " + qry
            + " with MBean " + oname, e);
        continue;
      } catch ( ReflectionException e ) {
        // This happens when the code inside the JMX bean threw an exception, so
        // log it and don't output the bean.
        LOG.error("Problem while trying to process JMX query: " + qry
            + " with MBean " + oname, e);
        continue;
      }

      jg.writeStartObject();
      jg.writeStringField("name", oname.toString());

      jg.writeStringField("modelerType", code);
      if ((attribute != null) && (attributeinfo == null)) {
        jg.writeStringField("result", "ERROR");
        jg.writeStringField("message", "No attribute with name " + attribute
            + " was found.");
        jg.writeEndObject();
        jg.writeEndArray();
        jg.close();
        response.setStatus(HttpServletResponse.SC_NOT_FOUND);
        return;
      }

      if (attribute != null) {
        writeAttribute(jg, attribute, attributeinfo);
      } else {
        MBeanAttributeInfo attrs[] = minfo.getAttributes();
        for (int i = 0; i < attrs.length; i++) {
          writeAttribute(jg, oname, attrs[i]);
        }
      }
      jg.writeEndObject();
    }
    jg.writeEndArray();
  }
Process a GET request for the specified resource.

@param request
         The servlet request we are processing
@param response
         The servlet response we are creating
common/src/java/org/apache/hive/http/JMXJsonServlet.java