HPROF is your friend (if you REALLY have nothing else at hand)

Official Java 7 doc https://docs.oracle.com/javase/7/docs/technotes/samples/hprof.html
http://www.oracle.com/technetwork/java/javase/tooldescr-136044.html#gblvj Excellent also this article http://www.brendangregg.com/blog/2014-06-09/java-cpu-sampling-using-hprof.html

I am using this stupid class to test:

import java.util.HashMap;

public class CUT {
  public static void main(String[] args) {
    try {
      for (int i = 0; i < 10000; i++) {
         Thread.sleep(1);
         HashMap<String, Object> m = new HashMap<String, Object>();
         m.put("1", new Object());
      }
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
}

then I run

javac -g CUT.java

java -agentlib:hprof=cpu=samples CUT

less java.hprof.txt 

this is what I get:

THREAD START (obj=50000193, id = 200001, name="main", group="main")
THREAD END (id = 200001)
THREAD START (obj=50000193, id = 200004, name="DestroyJavaVM", group="main")
THREAD END (id = 200004)
THREAD END (id = 200002)
TRACE 300050:
        java.lang.Thread.sleep(Thread.java:Unknown line)
        CUT.main(CUT.java:7)
TRACE 300014:
        sun.usagetracker.UsageTrackerClient.getPropertyPrivileged(UsageTrackerClient.java:136)
        sun.usagetracker.UsageTrackerClient.getPropertyPrivileged(UsageTrackerClient.java:132)
        sun.usagetracker.UsageTrackerClient.(UsageTrackerClient.java:109)
        sun.misc.PostVMInitHook.trackJavaUsage(PostVMInitHook.java:28)
TRACE 300026:
        java.lang.System.arraycopy(System.java:Unknown line)
        java.lang.String.getChars(String.java:826)
        java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:422)
        java.lang.StringBuffer.append(StringBuffer.java:272)
TRACE 300042:
        java.io.FilePermissionCollection.(FilePermission.java:711)
        java.io.FilePermission.newPermissionCollection(FilePermission.java:642)
        java.security.Permissions.getPermissionCollection(Permissions.java:254)
        java.security.Permissions.add(Permissions.java:132)
TRACE 300051:
        java.util.HashMap.putVal(HashMap.java:628)
        java.util.HashMap.put(HashMap.java:611)
        CUT.main(CUT.java:9)
TRACE 300052:
        java.util.HashMap.put(HashMap.java:611)
        CUT.main(CUT.java:9)
CPU SAMPLES BEGIN (total = 12) Wed Feb  3 06:07:50 2016
rank   self  accum   count trace method
   1 58.33% 58.33%       7 300050 java.lang.Thread.sleep
   2  8.33% 66.67%       1 300014 sun.usagetracker.UsageTrackerClient.getPropertyPrivileged
   3  8.33% 75.00%       1 300026 java.lang.System.arraycopy
   4  8.33% 83.33%       1 300042 java.io.FilePermissionCollection.
   5  8.33% 91.67%       1 300051 java.util.HashMap.putVal
   6  8.33% 100.00%       1 300052 java.util.HashMap.put
CPU SAMPLES END

Using the other option

java -agentlib:hprof=cpu=times CUT

gives me

THREAD START (obj=5000017d, id = 200002, name="HPROF gc_finish watcher", group="system")
THREAD START (obj=5000017d, id = 200001, name="main", group="main")
THREAD END (id = 200001)
THREAD START (obj=5000017d, id = 200003, name="DestroyJavaVM", group="main")
THREAD END (id = 200003)
THREAD END (id = 200002)
TRACE 301665:
        CUT.main(CUT.java:Unknown line)
TRACE 301663:
        java.util.HashMap.putVal(HashMap.java:Unknown line)
        java.util.HashMap.put(HashMap.java:Unknown line)
        CUT.main(CUT.java:Unknown line)
TRACE 301664:
        java.util.HashMap.put(HashMap.java:Unknown line)
        CUT.main(CUT.java:Unknown line)
TRACE 301657:
        java.util.HashMap.(HashMap.java:Unknown line)
        CUT.main(CUT.java:Unknown line)
TRACE 301659:
        java.util.HashMap.hash(HashMap.java:Unknown line)
        java.util.HashMap.put(HashMap.java:Unknown line)
        CUT.main(CUT.java:Unknown line)
TRACE 301661:
        java.util.HashMap.newNode(HashMap.java:Unknown line)
        java.util.HashMap.putVal(HashMap.java:Unknown line)
        java.util.HashMap.put(HashMap.java:Unknown line)
        CUT.main(CUT.java:Unknown line)
TRACE 301660:
        java.util.HashMap.resize(HashMap.java:Unknown line)
        java.util.HashMap.putVal(HashMap.java:Unknown line)
        java.util.HashMap.put(HashMap.java:Unknown line)
        CUT.main(CUT.java:Unknown line)
TRACE 301662:
        java.util.HashMap.afterNodeInsertion(HashMap.java:Unknown line)
        java.util.HashMap.putVal(HashMap.java:Unknown line)
        java.util.HashMap.put(HashMap.java:Unknown line)
        CUT.main(CUT.java:Unknown line)
TRACE 300952:
        java.util.HashMap$Node.(HashMap.java:Unknown line)
        java.util.HashMap.newNode(HashMap.java:Unknown line)
        java.util.HashMap.putVal(HashMap.java:Unknown line)
        java.util.HashMap.put(HashMap.java:Unknown line)
TRACE 301656:
        java.util.AbstractMap.(AbstractMap.java:Unknown line)
        java.util.HashMap.(HashMap.java:Unknown line)
        CUT.main(CUT.java:Unknown line)
TRACE 301658:
        java.lang.String.hashCode(String.java:Unknown line)
        java.util.HashMap.hash(HashMap.java:Unknown line)
        java.util.HashMap.put(HashMap.java:Unknown line)
        CUT.main(CUT.java:Unknown line)
TRACE 300163:
        java.lang.invoke.MethodHandle.(MethodHandle.java:Unknown line)
TRACE 300094:
        java.lang.invoke.MethodHandleImpl.(MethodHandleImpl.java:Unknown line)
        java.lang.invoke.MethodHandle.(MethodHandle.java:Unknown line)
TRACE 300252:
        java.lang.CharacterDataLatin1.getProperties(CharacterDataLatin1.java:Unknown line)
        java.lang.CharacterDataLatin1.toLowerCase(CharacterDataLatin1.java:Unknown line)
        java.lang.Character.toLowerCase(Character.java:Unknown line)
        java.lang.Character.toLowerCase(Character.java:Unknown line)
TRACE 301251:
        sun.misc.PerfCounter.(PerfCounter.java:Unknown line)
        sun.misc.PerfCounter.newPerfCounter(PerfCounter.java:Unknown line)
        sun.misc.PerfCounter$CoreCounters.(PerfCounter.java:Unknown line)
        sun.misc.PerfCounter.getReadClassBytesTime(PerfCounter.java:Unknown line)
CPU TIME (ms) BEGIN (total = 11886) Wed Feb  3 06:21:21 2016
rank   self  accum   count trace method
   1 94.75% 94.75%       1 301665 CUT.main
   2  1.10% 95.85%   10000 301663 java.util.HashMap.putVal
   3  0.83% 96.69%   10000 301664 java.util.HashMap.put
   4  0.75% 97.43%   10000 301657 java.util.HashMap.
   5  0.58% 98.01%   10000 301659 java.util.HashMap.hash
   6  0.41% 98.43%   10000 301661 java.util.HashMap.newNode
   7  0.27% 98.70%   10000 301660 java.util.HashMap.resize
   8  0.24% 98.93%   10000 301662 java.util.HashMap.afterNodeInsertion
   9  0.22% 99.15%   10016 300952 java.util.HashMap$Node.
  10  0.21% 99.36%   10000 301656 java.util.AbstractMap.
  11  0.15% 99.51%   10000 301658 java.lang.String.hashCode
  12  0.04% 99.55%       1 300163 java.lang.invoke.MethodHandle.
  13  0.02% 99.57%       1 300094 java.lang.invoke.MethodHandleImpl.
  14  0.02% 99.59%      80 300252 java.lang.CharacterDataLatin1.getProperties
  15  0.02% 99.60%       6 301251 sun.misc.PerfCounter.
CPU TIME (ms) END

which SEEMS much more accurate.
Heap Profiling uses this:

java -agentlib:hprof=heap=sites CUT

which gives (shortened form)

TRACE 300318:
        java.util.HashMap.resize(HashMap.java:703)
        java.util.HashMap.putVal(HashMap.java:628)
        java.util.HashMap.put(HashMap.java:611)
        CUT.main(CUT.java:9)

TRACE 300316:
        java.util.AbstractMap.(AbstractMap.java:73)
        java.util.HashMap.(HashMap.java:474)
        CUT.main(CUT.java:8)

TRACE 300186:
        java.util.HashMap$Node.(HashMap.java:284)
        java.util.HashMap.newNode(HashMap.java:1734)
        java.util.HashMap.putVal(HashMap.java:630)
        java.util.HashMap.put(HashMap.java:611)


(etc etc)

SITES BEGIN (ordered by live bytes) Wed Feb  3 06:28:22 2016
          percent          live          alloc'ed  stack class
 rank   self  accum     bytes objs     bytes  objs trace name
    1 39.18% 39.18%    800000 10000    800000 10000 300318 java.util.HashMap$Node[]
    2 23.51% 62.69%    480000 10000    480000 10000 300316 java.util.HashMap
    3 15.69% 78.38%    320384 10012    320384 10012 300186 java.util.HashMap$Node
    4  7.84% 86.22%    160000 10000    160000 10000 300317 java.lang.Object
    5  0.34% 86.56%      7000   53      7000    53 300011 char[]
    6  0.07% 86.63%      1504    4      1504     4 300001 java.lang.Thread
    7  0.06% 86.70%      1304   11      1304    11 300154 char[]
    8  0.06% 86.76%      1296    3      1296     3 300000 java.lang.Thread
    9  0.06% 86.82%      1248   11      1248    11 300172 char[]
   10  0.06% 86.88%      1248   11      1248    11 300173 char[]
   11  0.06% 86.94%      1240   10      1240    10 300176 char[]
   12  0.05% 86.99%      1040    1      1040     1 300021 java.lang.invoke.MethodHandle[]

To get help do:
java -agentlib:hprof=help

     HPROF: Heap and CPU Profiling Agent (JVMTI Demonstration Code)

hprof usage: java -agentlib:hprof=[help]|[=, ...]

Option Name and Value  Description                    Default
---------------------  -----------                    -------
heap=dump|sites|all    heap profiling                 all
cpu=samples|times|old  CPU usage                      off
monitor=y|n            monitor contention             n
format=a|b             text(txt) or binary output     a
file=            write data to file             java.hprof[{.txt}]
net=:      send data over a socket        off
depth=           stack trace depth              4
interval=          sample interval in ms          10
cutoff=         output cutoff point            0.0001
lineno=y|n             line number in traces?         y
thread=y|n             thread in traces?              n
doe=y|n                dump on exit?                  y
msa=y|n                Solaris micro state accounting n
force=y|n              force output to          y
verbose=y|n            print messages about dumps     y

Obsolete Options
----------------
gc_okay=y|n

Examples
--------
  - Get sample cpu information every 20 millisec, with a stack depth of 3:
      java -agentlib:hprof=cpu=samples,interval=20,depth=3 classname
  - Get heap usage information based on the allocation sites:
      java -agentlib:hprof=heap=sites classname

Notes
-----
  - The option format=b cannot be used with monitor=y.
  - The option format=b cannot be used with cpu=old|times.
  - Use of the -Xrunhprof interface can still be used, e.g.
       java -Xrunhprof:[help]|[=, ...]
    will behave exactly the same as:
       java -agentlib:hprof=[help]|[=, ...]

Warnings
--------
  - This is demonstration code for the JVMTI interface and use of BCI,
    it is not an official product or formal part of the JDK.
  - The -Xrunhprof interface will be removed in a future release.
  - The option format=b is considered experimental, this format may change
    in a future release.