jad

De-compile the specified classes.

jad helps to de-compile the byte code running in JVM to the source code to assist you to understand the logic behind better.

• The de-compiled code is syntax highlighted for better readability in Arthas console.
• It is possible that there’s grammar error in the de-compiled code, but it should not affect your interpretation.

Options

Name	Specification
class-pattern	pattern for the class name
[c:]	hashcode of the class loader that loads the class
[E]	turn on regex match while the default is wildcard match

Usage

If the target class is loaded by multiple classloaders, jad outputs the hashcode of the corresponding classloaders, then you can re-run jad and specify -c <hashcode> to de-compile the target class from the specified classloader.

$ jad org.apache.log4j.Logger

 Found more than one class for: org.apache.log4j.Logger, Please use jad -c hashcode org.apache.log4j.Logger
 HASHCODE  CLASSLOADER
 69dcaba4  +-monitor's ModuleClassLoader
 6e51ad67  +-java.net.URLClassLoader@6e51ad67
             +-sun.misc.Launcher$AppClassLoader@6951a712
               +-sun.misc.Launcher$ExtClassLoader@6fafc4c2
 2bdd9114  +-pandora-qos-service's ModuleClassLoader
 4c0df5f8  +-pandora-framework's ModuleClassLoader

Affect(row-cnt:0) cost in 38 ms.
$ jad org.apache.log4j.Logger -c 69dcaba4

ClassLoader:
+-monitor's ModuleClassLoader

Location:
/Users/zhuyong/Downloads/taobao-hsf.sar/plugins/monitor/lib/log4j-1.2.14.jar

package org.apache.log4j;

import org.apache.log4j.spi.*;

public class Logger extends Category
{
    private static final String FQCN;

    protected Logger(String name)
    {
        super(name);
    }

    public static Logger getLogger(String name)
    {
        return LogManager.getLogger(name);
    }

    public static Logger getLogger(Class clazz)
    {
        return LogManager.getLogger(clazz.getName());
    }

    public static Logger getRootLogger()
    {
        return LogManager.getRootLogger();
    }

    public static Logger getLogger(String name, LoggerFactory factory)
    {
        return LogManager.getLogger(name, factory);
    }

    public void trace(Object message)
    {
        if (repository.isDisabled(5000))
        {
            return;
        }
        if (Level.TRACE.isGreaterOrEqual(getEffectiveLevel()))
        {
            forcedLog(Logger.FQCN, Level.TRACE, message, null);
        }
    }

    public void trace(Object message, Throwable t)
    {
        if (repository.isDisabled(5000))
        {
            return;
        }
        if (Level.TRACE.isGreaterOrEqual(getEffectiveLevel()))
        {
            forcedLog(Logger.FQCN, Level.TRACE, message, t);
        }
    }

    public boolean isTraceEnabled()
    {
        if (repository.isDisabled(5000))
        {
            return false;
        }
        return Level.TRACE.isGreaterOrEqual(getEffectiveLevel());
    }

    static
    {
        Logger.FQCN = Logger.class.getName();
    }

}

Affect(row-cnt:1) cost in 190 ms.

De-compile the specified method:

$ jad com.taobao.container.web.arthas.rest.MetricsController directMetrics

ClassLoader:
+-com.taobao.pandora.boot.loader.ReLaunchURLClassLoader@1817d444
  +-sun.misc.Launcher$AppClassLoader@14dad5dc
    +-sun.misc.Launcher$ExtClassLoader@a38d7a3

Location:
/Users/zhuyong/middleware/tomcat-web/tomcat-web-web/target/classes/

private Map<String, Object> directMetrics(String ip, String[] metrics) {
    JSONObject obj;
    HashMap<String, Object> result = new HashMap<String, Object>();
    result.put("success", false);
    String metricUrl = "http://" + ip + ":8006/metrics/specific";
    String postBody = Arrays.stream(metrics).map(metric -> "metric=" + metric).collect(Collectors.joining("&"));
    HttpClientUtils.Response resp = HttpClientUtils.sendPostRequest((String)metricUrl, (String)postBody);
    if (resp.isSuccess() && (obj = JSON.parseObject(resp.getContent())).containsKey("success") && obj.getBoolean("success").booleanValue() && obj.containsKey("data")) {
        JSONArray dataArray = obj.getJSONArray("data");
        HashMap<String, Object> metricMap = new HashMap<String, Object>();
        for (Object aDataArray : dataArray) {
            JSONObject o = (JSONObject)aDataArray;
            metricMap.put(o.getString("metric"), o.get("value"));
        }
        result.put("data", metricMap);
        result.put("success", true);
        return result;
    }
    return result;
}

Affect(row-cnt:1) cost in 1508 ms.