hbase-http/src/main/java/org/apache/hadoop/hbase/util/JSONBean.java - hbase - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package org.apache.hadoop.hbase.util;

 import java.io.Closeable;
 import java.io.IOException;
 import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
 import java.lang.management.ManagementFactory;
 import java.lang.reflect.Array;
 import java.nio.charset.StandardCharsets;
 import java.util.Iterator;
 import java.util.Set;
 import java.util.regex.Pattern;
 import javax.management.AttributeNotFoundException;
 import javax.management.InstanceNotFoundException;
 import javax.management.IntrospectionException;
 import javax.management.MBeanAttributeInfo;
 import javax.management.MBeanException;
 import javax.management.MBeanInfo;
 import javax.management.MBeanServer;
 import javax.management.MalformedObjectNameException;
 import javax.management.ObjectName;
 import javax.management.ReflectionException;
 import javax.management.RuntimeErrorException;
 import javax.management.RuntimeMBeanException;
 import javax.management.openmbean.CompositeData;
 import javax.management.openmbean.CompositeType;
 import javax.management.openmbean.TabularData;
 import org.apache.yetus.audience.InterfaceAudience;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import org.apache.hbase.thirdparty.com.google.gson.Gson;
 import org.apache.hbase.thirdparty.com.google.gson.stream.JsonWriter;

 /**
  * Utility for doing JSON and MBeans.
  */
 @InterfaceAudience.Private
 public class JSONBean {
   private static final String COMMA = ",";
   private static final String ASTERICK = "*";
   private static final Logger LOG = LoggerFactory.getLogger(JSONBean.class);
   private static final Gson GSON = GsonUtil.createGsonWithDisableHtmlEscaping().create();

   /**
    * Use dumping out mbeans as JSON.
    */
   public interface Writer extends Closeable {

     void write(String key, String value) throws IOException;

     default int write(MBeanServer mBeanServer, ObjectName qry, String attribute,
       boolean description) throws IOException {
       return write(mBeanServer, qry, attribute, description, null);
     }

     int write(MBeanServer mBeanServer, ObjectName qry, String attribute, boolean description,
       ObjectName excluded) throws IOException;

     void flush() throws IOException;
   }

   /**
    * Notice that, closing the return {@link Writer} will not close the {@code writer} passed in, you
    * still need to close the {@code writer} by yourself.
    * <p/>
    * This is because that, we can only finish the json after you call {@link Writer#close()}. So if
    * we just close the {@code writer}, you can write nothing after finished the json.
    */
   public Writer open(final PrintWriter writer) throws IOException {
     JsonWriter jsonWriter = GSON.newJsonWriter(new java.io.Writer() {

       @Override
       public void write(char[] cbuf, int off, int len) throws IOException {
         writer.write(cbuf, off, len);
       }

       @Override
       public void flush() throws IOException {
         writer.flush();
       }

       @Override
       public void close() throws IOException {
         // do nothing
       }
     });
     jsonWriter.setIndent("  ");
     jsonWriter.beginObject();
     return new Writer() {
       @Override
       public void flush() throws IOException {
         jsonWriter.flush();
       }

       @Override
       public void close() throws IOException {
         jsonWriter.endObject();
         jsonWriter.close();
       }

       @Override
       public void write(String key, String value) throws IOException {
         jsonWriter.name(key).value(value);
       }

       @Override
       public int write(MBeanServer mBeanServer, ObjectName qry, String attribute,
         boolean description, ObjectName excluded) throws IOException {
         return JSONBean.write(jsonWriter, mBeanServer, qry, attribute, description, excluded);
       }
     };
   }

   /** Returns Return non-zero if failed to find bean. 0 */
   private static int write(JsonWriter writer, MBeanServer mBeanServer, ObjectName qry,
     String attribute, boolean description, ObjectName excluded) throws IOException {
     LOG.debug("Listing beans for {}", qry);
     Set<ObjectName> names = mBeanServer.queryNames(qry, null);
     writer.name("beans").beginArray();
     Iterator<ObjectName> it = names.iterator();
     Pattern[] matchingPattern = null;
     while (it.hasNext()) {
       ObjectName oname = it.next();
       if (excluded != null && excluded.apply(oname)) {
         continue;
       }
       MBeanInfo minfo;
       String code = "";
       String descriptionStr = null;
       Object attributeinfo = null;
       try {
         minfo = mBeanServer.getMBeanInfo(oname);
         code = minfo.getClassName();
         if (description) {
           descriptionStr = minfo.getDescription();
         }
         String prs = "";
         try {
           if ("org.apache.commons.modeler.BaseModelMBean".equals(code)) {
             prs = "modelerType";
             code = (String) mBeanServer.getAttribute(oname, prs);
           }
           if (attribute != null) {
             String[] patternAttr = null;
             if (attribute.contains(ASTERICK)) {
               if (attribute.contains(COMMA)) {
                 patternAttr = attribute.split(COMMA);
               } else {
                 patternAttr = new String[1];
                 patternAttr[0] = attribute;
               }
               matchingPattern = new Pattern[patternAttr.length];
               for (int i = 0; i < patternAttr.length; i++) {
                 matchingPattern[i] = Pattern.compile(patternAttr[i]);
               }
               // nullify the attribute
               attribute = null;
             } else {
               prs = attribute;
               attributeinfo = mBeanServer.getAttribute(oname, prs);
             }
           }
         } catch (RuntimeMBeanException e) {
           // UnsupportedOperationExceptions happen in the normal course of business,
           // so no need to log them as errors all the time.
           if (e.getCause() instanceof UnsupportedOperationException) {
             if (LOG.isTraceEnabled()) {
               LOG.trace("Getting attribute " + prs + " of " + oname + " threw " + e);
             }
           } else {
             LOG.error("Getting attribute " + prs + " of " + oname + " threw an exception", e);
           }
           return 0;
         } 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 exceptionscan 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;
       }
       writer.beginObject();
       writer.name("name").value(oname.toString());
       if (description && descriptionStr != null && descriptionStr.length() > 0) {
         writer.name("description").value(descriptionStr);
       }
       writer.name("modelerType").value(code);
       if (attribute != null && attributeinfo == null) {
         writer.name("result").value("ERROR");
         writer.name("message").value("No attribute with name " + attribute + " was found.");
         writer.endObject();
         writer.endArray();
         writer.close();
         return -1;
       }

       if (attribute != null) {
         writeAttribute(writer, attribute, descriptionStr, attributeinfo);
       } else {
         MBeanAttributeInfo[] attrs = minfo.getAttributes();
         for (int i = 0; i < attrs.length; i++) {
           writeAttribute(writer, mBeanServer, oname, description, matchingPattern, attrs[i]);
         }
       }
       writer.endObject();
     }
     writer.endArray();
     return 0;
   }

   private static void writeAttribute(JsonWriter writer, MBeanServer mBeanServer, ObjectName oname,
     boolean description, Pattern pattern[], MBeanAttributeInfo attr) throws IOException {
     if (!attr.isReadable()) {
       return;
     }
     String attName = attr.getName();
     if ("modelerType".equals(attName)) {
       return;
     }
     if (attName.indexOf("=") >= 0 || attName.indexOf(" ") >= 0) {
       return;
     }

     if (pattern != null) {
       boolean matchFound = false;
       for (Pattern compile : pattern) {
         // check if we have any match
         if (compile.matcher(attName).find()) {
           matchFound = true;
           break;
         }
       }
       if (!matchFound) {
         return;
       }
     }

     String descriptionStr = description ? attr.getDescription() : null;
     Object value = null;
     try {
       value = mBeanServer.getAttribute(oname, attName);
     } catch (RuntimeMBeanException e) {
       // UnsupportedOperationExceptions happen in the normal course of business,
       // so no need to log them as errors all the time.
       if (e.getCause() instanceof UnsupportedOperationException) {
         if (LOG.isTraceEnabled()) {
           LOG.trace("Getting attribute " + attName + " of " + oname + " threw " + e);
         }
       } else {
         LOG.error("getting attribute " + attName + " of " + oname + " threw an exception", e);
       }
       return;
     } catch (RuntimeErrorException e) {
       // RuntimeErrorException happens when an unexpected failure occurs in getAttribute
       // for example https://issues.apache.org/jira/browse/DAEMON-120
       LOG.debug("getting attribute " + attName + " of " + oname + " threw an exception", e);
       return;
     } catch (AttributeNotFoundException e) {
       // Ignored the attribute was not found, which should never happen because the bean
       // just told us that it has this attribute, but if this happens just don't output
       // the attribute.
       return;
     } catch (MBeanException e) {
       // The code inside the attribute getter threw an exception so log it, and
       // skip outputting the attribute
       LOG.error("getting attribute " + attName + " of " + oname + " threw an exception", e);
       return;
     } 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 " + attName + " of " + oname + " threw an exception", e);
       return;
     } catch (ReflectionException e) {
       // This happens when the code inside the JMX bean (setter?? from the java docs)
       // threw an exception, so log it and skip outputting the attribute
       LOG.error("getting attribute " + attName + " of " + oname + " threw an exception", e);
       return;
     } catch (InstanceNotFoundException e) {
       // Ignored the mbean itself was not found, which should never happen because we
       // just accessed it (perhaps something unregistered in-between) but if this
       // happens just don't output the attribute.
       return;
     }

     writeAttribute(writer, attName, descriptionStr, value);
   }

   private static void writeAttribute(JsonWriter writer, String attName, String descriptionStr,
     Object value) throws IOException {
     if (descriptionStr != null && descriptionStr.length() > 0 && !attName.equals(descriptionStr)) {
       writer.name(attName);
       writer.beginObject();
       writer.name("description").value(descriptionStr);
       writer.name("value");
       writeObject(writer, value);
       writer.endObject();
     } else {
       writer.name(attName);
       writeObject(writer, value);
     }
   }

   private static void writeObject(JsonWriter writer, Object value) throws IOException {
     if (value == null) {
       writer.nullValue();
     } else {
       Class<?> c = value.getClass();
       if (c.isArray()) {
         writer.beginArray();
         int len = Array.getLength(value);
         for (int j = 0; j < len; j++) {
           Object item = Array.get(value, j);
           writeObject(writer, item);
         }
         writer.endArray();
       } else if (value instanceof Number) {
         Number n = (Number) value;
         if (Double.isFinite(n.doubleValue())) {
           writer.value(n);
         } else {
           writer.value(n.toString());
         }
       } else if (value instanceof Boolean) {
         Boolean b = (Boolean) value;
         writer.value(b);
       } else if (value instanceof CompositeData) {
         CompositeData cds = (CompositeData) value;
         CompositeType comp = cds.getCompositeType();
         Set<String> keys = comp.keySet();
         writer.beginObject();
         for (String key : keys) {
           writeAttribute(writer, key, null, cds.get(key));
         }
         writer.endObject();
       } else if (value instanceof TabularData) {
         TabularData tds = (TabularData) value;
         writer.beginArray();
         for (Object entry : tds.values()) {
           writeObject(writer, entry);
         }
         writer.endArray();
       } else {
         writer.value(value.toString());
       }
     }
   }

   /**
    * Dump out all registered mbeans as json on System.out.
    */
   public static void dumpAllBeans() throws IOException, MalformedObjectNameException {
     try (PrintWriter writer =
       new PrintWriter(new OutputStreamWriter(System.out, StandardCharsets.UTF_8))) {
       JSONBean dumper = new JSONBean();
       try (JSONBean.Writer jsonBeanWriter = dumper.open(writer)) {
         MBeanServer mbeanServer = ManagementFactory.getPlatformMBeanServer();
         jsonBeanWriter.write(mbeanServer, new ObjectName("*:*"), null, false);
       }
     }
   }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package org.apache.hadoop.hbase.util;

	import java.io.Closeable;
	import java.io.IOException;
	import java.io.OutputStreamWriter;
	import java.io.PrintWriter;
	import java.lang.management.ManagementFactory;
	import java.lang.reflect.Array;
	import java.nio.charset.StandardCharsets;
	import java.util.Iterator;
	import java.util.Set;
	import java.util.regex.Pattern;
	import javax.management.AttributeNotFoundException;
	import javax.management.InstanceNotFoundException;
	import javax.management.IntrospectionException;
	import javax.management.MBeanAttributeInfo;
	import javax.management.MBeanException;
	import javax.management.MBeanInfo;
	import javax.management.MBeanServer;
	import javax.management.MalformedObjectNameException;
	import javax.management.ObjectName;
	import javax.management.ReflectionException;
	import javax.management.RuntimeErrorException;
	import javax.management.RuntimeMBeanException;
	import javax.management.openmbean.CompositeData;
	import javax.management.openmbean.CompositeType;
	import javax.management.openmbean.TabularData;
	import org.apache.yetus.audience.InterfaceAudience;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	import org.apache.hbase.thirdparty.com.google.gson.Gson;
	import org.apache.hbase.thirdparty.com.google.gson.stream.JsonWriter;

	/**
	* Utility for doing JSON and MBeans.
	*/
	@InterfaceAudience.Private
	public class JSONBean {
	private static final String COMMA = ",";
	private static final String ASTERICK = "*";
	private static final Logger LOG = LoggerFactory.getLogger(JSONBean.class);
	private static final Gson GSON = GsonUtil.createGsonWithDisableHtmlEscaping().create();

	/**
	* Use dumping out mbeans as JSON.
	*/
	public interface Writer extends Closeable {

	void write(String key, String value) throws IOException;

	default int write(MBeanServer mBeanServer, ObjectName qry, String attribute,
	boolean description) throws IOException {
	return write(mBeanServer, qry, attribute, description, null);
	}

	int write(MBeanServer mBeanServer, ObjectName qry, String attribute, boolean description,
	ObjectName excluded) throws IOException;

	void flush() throws IOException;
	}

	/**
	* Notice that, closing the return {@link Writer} will not close the {@code writer} passed in, you
	* still need to close the {@code writer} by yourself.
	* <p/>
	* This is because that, we can only finish the json after you call {@link Writer#close()}. So if
	* we just close the {@code writer}, you can write nothing after finished the json.
	*/
	public Writer open(final PrintWriter writer) throws IOException {
	JsonWriter jsonWriter = GSON.newJsonWriter(new java.io.Writer() {

	@Override
	public void write(char[] cbuf, int off, int len) throws IOException {
	writer.write(cbuf, off, len);
	}

	@Override
	public void flush() throws IOException {
	writer.flush();
	}

	@Override
	public void close() throws IOException {
	// do nothing
	}
	});
	jsonWriter.setIndent(" ");
	jsonWriter.beginObject();
	return new Writer() {
	@Override
	public void flush() throws IOException {
	jsonWriter.flush();
	}

	@Override
	public void close() throws IOException {
	jsonWriter.endObject();
	jsonWriter.close();
	}

	@Override
	public void write(String key, String value) throws IOException {
	jsonWriter.name(key).value(value);
	}

	@Override
	public int write(MBeanServer mBeanServer, ObjectName qry, String attribute,
	boolean description, ObjectName excluded) throws IOException {
	return JSONBean.write(jsonWriter, mBeanServer, qry, attribute, description, excluded);
	}
	};
	}

	/** Returns Return non-zero if failed to find bean. 0 */
	private static int write(JsonWriter writer, MBeanServer mBeanServer, ObjectName qry,
	String attribute, boolean description, ObjectName excluded) throws IOException {
	LOG.debug("Listing beans for {}", qry);
	Set<ObjectName> names = mBeanServer.queryNames(qry, null);
	writer.name("beans").beginArray();
	Iterator<ObjectName> it = names.iterator();
	Pattern[] matchingPattern = null;
	while (it.hasNext()) {
	ObjectName oname = it.next();
	if (excluded != null && excluded.apply(oname)) {
	continue;
	}
	MBeanInfo minfo;
	String code = "";
	String descriptionStr = null;
	Object attributeinfo = null;
	try {
	minfo = mBeanServer.getMBeanInfo(oname);
	code = minfo.getClassName();
	if (description) {
	descriptionStr = minfo.getDescription();
	}
	String prs = "";
	try {
	if ("org.apache.commons.modeler.BaseModelMBean".equals(code)) {
	prs = "modelerType";
	code = (String) mBeanServer.getAttribute(oname, prs);
	}
	if (attribute != null) {
	String[] patternAttr = null;
	if (attribute.contains(ASTERICK)) {
	if (attribute.contains(COMMA)) {
	patternAttr = attribute.split(COMMA);
	} else {
	patternAttr = new String[1];
	patternAttr[0] = attribute;
	}
	matchingPattern = new Pattern[patternAttr.length];
	for (int i = 0; i < patternAttr.length; i++) {
	matchingPattern[i] = Pattern.compile(patternAttr[i]);
	}
	// nullify the attribute
	attribute = null;
	} else {
	prs = attribute;
	attributeinfo = mBeanServer.getAttribute(oname, prs);
	}
	}
	} catch (RuntimeMBeanException e) {
	// UnsupportedOperationExceptions happen in the normal course of business,
	// so no need to log them as errors all the time.
	if (e.getCause() instanceof UnsupportedOperationException) {
	if (LOG.isTraceEnabled()) {
	LOG.trace("Getting attribute " + prs + " of " + oname + " threw " + e);
	}
	} else {
	LOG.error("Getting attribute " + prs + " of " + oname + " threw an exception", e);
	}
	return 0;
	} 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 exceptionscan 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;
	}
	writer.beginObject();
	writer.name("name").value(oname.toString());
	if (description && descriptionStr != null && descriptionStr.length() > 0) {
	writer.name("description").value(descriptionStr);
	}
	writer.name("modelerType").value(code);
	if (attribute != null && attributeinfo == null) {
	writer.name("result").value("ERROR");
	writer.name("message").value("No attribute with name " + attribute + " was found.");
	writer.endObject();
	writer.endArray();
	writer.close();
	return -1;
	}

	if (attribute != null) {
	writeAttribute(writer, attribute, descriptionStr, attributeinfo);
	} else {
	MBeanAttributeInfo[] attrs = minfo.getAttributes();
	for (int i = 0; i < attrs.length; i++) {
	writeAttribute(writer, mBeanServer, oname, description, matchingPattern, attrs[i]);
	}
	}
	writer.endObject();
	}
	writer.endArray();
	return 0;
	}

	private static void writeAttribute(JsonWriter writer, MBeanServer mBeanServer, ObjectName oname,
	boolean description, Pattern pattern[], MBeanAttributeInfo attr) throws IOException {
	if (!attr.isReadable()) {
	return;
	}
	String attName = attr.getName();
	if ("modelerType".equals(attName)) {
	return;
	}
	if (attName.indexOf("=") >= 0 \|\| attName.indexOf(" ") >= 0) {
	return;
	}

	if (pattern != null) {
	boolean matchFound = false;
	for (Pattern compile : pattern) {
	// check if we have any match
	if (compile.matcher(attName).find()) {
	matchFound = true;
	break;
	}
	}
	if (!matchFound) {
	return;
	}
	}

	String descriptionStr = description ? attr.getDescription() : null;
	Object value = null;
	try {
	value = mBeanServer.getAttribute(oname, attName);
	} catch (RuntimeMBeanException e) {
	// UnsupportedOperationExceptions happen in the normal course of business,
	// so no need to log them as errors all the time.
	if (e.getCause() instanceof UnsupportedOperationException) {
	if (LOG.isTraceEnabled()) {
	LOG.trace("Getting attribute " + attName + " of " + oname + " threw " + e);
	}
	} else {
	LOG.error("getting attribute " + attName + " of " + oname + " threw an exception", e);
	}
	return;
	} catch (RuntimeErrorException e) {
	// RuntimeErrorException happens when an unexpected failure occurs in getAttribute
	// for example https://issues.apache.org/jira/browse/DAEMON-120
	LOG.debug("getting attribute " + attName + " of " + oname + " threw an exception", e);
	return;
	} catch (AttributeNotFoundException e) {
	// Ignored the attribute was not found, which should never happen because the bean
	// just told us that it has this attribute, but if this happens just don't output
	// the attribute.
	return;
	} catch (MBeanException e) {
	// The code inside the attribute getter threw an exception so log it, and
	// skip outputting the attribute
	LOG.error("getting attribute " + attName + " of " + oname + " threw an exception", e);
	return;
	} 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 " + attName + " of " + oname + " threw an exception", e);
	return;
	} catch (ReflectionException e) {
	// This happens when the code inside the JMX bean (setter?? from the java docs)
	// threw an exception, so log it and skip outputting the attribute
	LOG.error("getting attribute " + attName + " of " + oname + " threw an exception", e);
	return;
	} catch (InstanceNotFoundException e) {
	// Ignored the mbean itself was not found, which should never happen because we
	// just accessed it (perhaps something unregistered in-between) but if this
	// happens just don't output the attribute.
	return;
	}

	writeAttribute(writer, attName, descriptionStr, value);
	}

	private static void writeAttribute(JsonWriter writer, String attName, String descriptionStr,
	Object value) throws IOException {
	if (descriptionStr != null && descriptionStr.length() > 0 && !attName.equals(descriptionStr)) {
	writer.name(attName);
	writer.beginObject();
	writer.name("description").value(descriptionStr);
	writer.name("value");
	writeObject(writer, value);
	writer.endObject();
	} else {
	writer.name(attName);
	writeObject(writer, value);
	}
	}

	private static void writeObject(JsonWriter writer, Object value) throws IOException {
	if (value == null) {
	writer.nullValue();
	} else {
	Class<?> c = value.getClass();
	if (c.isArray()) {
	writer.beginArray();
	int len = Array.getLength(value);
	for (int j = 0; j < len; j++) {
	Object item = Array.get(value, j);
	writeObject(writer, item);
	}
	writer.endArray();
	} else if (value instanceof Number) {
	Number n = (Number) value;
	if (Double.isFinite(n.doubleValue())) {
	writer.value(n);
	} else {
	writer.value(n.toString());
	}
	} else if (value instanceof Boolean) {
	Boolean b = (Boolean) value;
	writer.value(b);
	} else if (value instanceof CompositeData) {
	CompositeData cds = (CompositeData) value;
	CompositeType comp = cds.getCompositeType();
	Set<String> keys = comp.keySet();
	writer.beginObject();
	for (String key : keys) {
	writeAttribute(writer, key, null, cds.get(key));
	}
	writer.endObject();
	} else if (value instanceof TabularData) {
	TabularData tds = (TabularData) value;
	writer.beginArray();
	for (Object entry : tds.values()) {
	writeObject(writer, entry);
	}
	writer.endArray();
	} else {
	writer.value(value.toString());
	}
	}
	}

	/**
	* Dump out all registered mbeans as json on System.out.
	*/
	public static void dumpAllBeans() throws IOException, MalformedObjectNameException {
	try (PrintWriter writer =
	new PrintWriter(new OutputStreamWriter(System.out, StandardCharsets.UTF_8))) {
	JSONBean dumper = new JSONBean();
	try (JSONBean.Writer jsonBeanWriter = dumper.open(writer)) {
	MBeanServer mbeanServer = ManagementFactory.getPlatformMBeanServer();
	jsonBeanWriter.write(mbeanServer, new ObjectName(":"), null, false);
	}
	}
	}
	}