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Common functionality for HBase
/*
* 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 com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.core.JsonGenerator;
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 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;
/**
* Utility for doing JSON and MBeans.
*/
@InterfaceAudience.Private
public class JSONBean {
private static final Logger LOG = LoggerFactory.getLogger(JSONBean.class);
private final JsonFactory jsonFactory;
public JSONBean() {
this.jsonFactory = new JsonFactory();
}
/**
* Use dumping out mbeans as JSON.
*/
public interface Writer extends Closeable {
void write(final String key, final String value) throws JsonGenerationException, IOException;
int write(final MBeanServer mBeanServer, ObjectName qry, String attribute,
final boolean description) throws IOException;
void flush() throws IOException;
}
public Writer open(final PrintWriter writer) throws IOException {
final JsonGenerator jg = jsonFactory.createJsonGenerator(writer);
jg.disable(JsonGenerator.Feature.AUTO_CLOSE_TARGET);
jg.useDefaultPrettyPrinter();
jg.writeStartObject();
return new Writer() {
@Override
public void flush() throws IOException {
jg.flush();
}
@Override
public void close() throws IOException {
jg.close();
}
@Override
public void write(String key, String value) throws JsonGenerationException, IOException {
jg.writeStringField(key, value);
}
@Override
public int write(MBeanServer mBeanServer, ObjectName qry, String attribute,
boolean description)
throws IOException {
return JSONBean.write(jg, mBeanServer, qry, attribute, description);
}
};
}
/**
* @return Return non-zero if failed to find bean. 0
*/
private static int write(final JsonGenerator jg,
final MBeanServer mBeanServer, ObjectName qry, String attribute,
final boolean description)
throws IOException {
LOG.trace("Listing beans for "+qry);
Set names = null;
names = mBeanServer.queryNames(qry, null);
jg.writeArrayFieldStart("beans");
Iterator it = names.iterator();
while (it.hasNext()) {
ObjectName oname = it.next();
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) {
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;
}
jg.writeStartObject();
jg.writeStringField("name", oname.toString());
if (description && descriptionStr != null && descriptionStr.length() > 0) {
jg.writeStringField("description", descriptionStr);
}
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();
return -1;
}
if (attribute != null) {
writeAttribute(jg, attribute, descriptionStr, attributeinfo);
} else {
MBeanAttributeInfo[] attrs = minfo.getAttributes();
for (int i = 0; i < attrs.length; i++) {
writeAttribute(jg, mBeanServer, oname, description, attrs[i]);
}
}
jg.writeEndObject();
}
jg.writeEndArray();
return 0;
}
private static void writeAttribute(final JsonGenerator jg,
final MBeanServer mBeanServer, ObjectName oname,
final boolean description, final MBeanAttributeInfo attr)
throws IOException {
if (!attr.isReadable()) {
return;
}
String attName = attr.getName();
if ("modelerType".equals(attName)) {
return;
}
if (attName.indexOf("=") >= 0 || attName.indexOf(":") >= 0 || attName.indexOf(" ") >= 0) {
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(jg, attName, descriptionStr, value);
}
private static void writeAttribute(JsonGenerator jg, String attName, final String descriptionStr,
Object value)
throws IOException {
boolean description = false;
if (descriptionStr != null && descriptionStr.length() > 0 && !attName.equals(descriptionStr)) {
description = true;
jg.writeFieldName(attName);
jg.writeStartObject();
jg.writeFieldName("description");
jg.writeString(descriptionStr);
jg.writeFieldName("value");
writeObject(jg, description, value);
jg.writeEndObject();
} else {
jg.writeFieldName(attName);
writeObject(jg, description, value);
}
}
private static void writeObject(final JsonGenerator jg, final boolean description, Object value)
throws IOException {
if(value == null) {
jg.writeNull();
} else {
Class c = value.getClass();
if (c.isArray()) {
jg.writeStartArray();
int len = Array.getLength(value);
for (int j = 0; j < len; j++) {
Object item = Array.get(value, j);
writeObject(jg, description, item);
}
jg.writeEndArray();
} else if(value instanceof Number) {
Number n = (Number)value;
if (Double.isFinite(n.doubleValue())) {
jg.writeNumber(n.toString());
} else {
jg.writeString(n.toString());
}
} else if(value instanceof Boolean) {
Boolean b = (Boolean)value;
jg.writeBoolean(b);
} else if(value instanceof CompositeData) {
CompositeData cds = (CompositeData)value;
CompositeType comp = cds.getCompositeType();
Set keys = comp.keySet();
jg.writeStartObject();
for (String key: keys) {
writeAttribute(jg, key, null, cds.get(key));
}
jg.writeEndObject();
} else if(value instanceof TabularData) {
TabularData tds = (TabularData)value;
jg.writeStartArray();
for(Object entry : tds.values()) {
writeObject(jg, description, entry);
}
jg.writeEndArray();
} else {
jg.writeString(value.toString());
}
}
}
/**
* Dump out all registered mbeans as json on System.out.
* @throws IOException
* @throws MalformedObjectNameException
*/
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);
}
}
}
}