How to get the caller class in Java

Question

I want to get the caller class of the method  i e    class foo     bar         In the method bar  I need to get the class name foo  and I found this method   Class clazz   sun reflect Reflection getCallerClass 1     However  even though getCallerClass is public  when I try to call it Eclipse says      Access restriction  The method getCallerClass   from the type   Reflection is not accessible due to restriction on required library   C  Program Files Java jre7 lib rt jar   Are there any other choices

User · Answer

Since I currently have the same problem here is what I do:

I prefer com.sun.Reflection instead of stackTrace since a stack trace is only producing the name not the class (including the classloader) itself.
The method is deprecated but still around in Java 8 SDK.

// Method descriptor #124 (I)Ljava/lang/Class; (deprecated) // Signature: (I)Ljava/lang/Class<*>; @java.lang.Deprecated public static native java.lang.Class getCallerClass(int arg0);

The method without int argument is not deprecated

// Method descriptor #122 ()Ljava/lang/Class; // Signature: ()Ljava/lang/Class<*>; @sun.reflect.CallerSensitive public static native java.lang.Class getCallerClass();

Since I have to be platform independent bla bla including Security Restrictions, I just create a flexible method:

Check if com.sun.Reflection is available (security exceptions disable this mechanism)
If 1 is yes then get the method with int or no int argument.
If 2 is yes call it.

If 3. was never reached, I use the stack trace to return the name. I use a special result object that contains either the class or the string and this object tells exactly what it is and why.

[Summary] I use stacktrace for backup and to bypass eclipse compiler warnings I use reflections. Works very good. Keeps the code clean, works like a charm and also states the problems involved correctly.

I use this for quite a long time and today I searched a related question so

User · Answer

Find below a simple example illustrating how to get class and method names   public static void main String args               callMe             void callMe              try                  throw new Exception  Who called me                   catch  Exception e                    System out println   I was called by                                   e getStackTrace   1  getClassName                                                                      e getStackTrace   1  getMethodName                                                           e has getClassName    getFileName    getLineNumber   and getMethodName

User · Answer

The error message the OP is encountering is just an Eclipse feature   If you are willing to tie your code to a specific maker  and even version  of the JVM  you can effectively use method sun reflect Reflection getCallerClass     You can then compile the code outside of Eclipse or configure it not to consider this diagnostic an error   The worse Eclipse configuration is to disable all occurrences of the error by   Project Properties   Java Compiler   Errors Warnings   Enable project specific settings set to checked   Deprecated and restrited API   Forbidden reference  access rules  set to Warning or Ignore   The better Eclipse configuration is to disable a specific occurrence of the error by   Project Properties   Java Build Path   Libraries   JRE System Library expand   Access rules  select   Edit      Add      Resolution  set to Discouraged or Accessible   Rule Pattern set to sun reflect Reflection

User · Answer

i am using the following method to get the caller for a specific class from the stacktrace   package test log   public class CallerClassTest        public static void main final String   args            final Caller caller   new Caller new Callee             caller execute               private static class Caller            private final Callee c           public Caller final Callee c                this c   c                     void execute                 c call                         static class Callee            void call                 System out println getCallerClassName this getClass                                      Searches the current threads stacktrace for the class that called the given class  Returns   code null  if the        calling class could not be found                  param clazz                   the class that has been called                 return the caller that called the class or   code null              public static String getCallerClassName final Class lt   gt  clazz            final StackTraceElement   stackTrace   Thread currentThread   getStackTrace            final String className   clazz getName            boolean classFound   false          for  int i   1  i  lt  stackTrace length  i                  final StackTraceElement element   stackTrace i               final String callerClassName   element getClassName                   check if class name is the requested class             if  callerClassName equals className   classFound   true              else if  classFound  return callerClassName                    return null

User · Answer

To get caller called class name use below code  it works fine for me   String callerClassName   new Exception   getStackTrace   1  getClassName    String calleeClassName   new Exception   getStackTrace   0  getClassName

User · Answer

This is the most efficient way to get just the callers class  Other approaches take an entire stack dump and only give you the class name   However  this class in under sun   which is really for internal use   This means that it may not work on other Java platforms or even other Java versions   You have to decide whether this is a problem or not

User · Answer

You can generate a stack trace and use the informations in the StackTraceElements   For example an utility class can return you the calling class name    public class KDebug       public static String getCallerClassName              StackTraceElement   stElements   Thread currentThread   getStackTrace            for  int i 1  i lt stElements length  i                  StackTraceElement ste   stElements i               if   ste getClassName   equals KDebug class getName     amp  amp  ste getClassName   indexOf  java lang Thread    0                    return ste getClassName                                    return null             If you call KDebug getCallerClassName   from bar    you ll get  foo    Now supposing you want to know the class of the method calling bar  which is more interesting and maybe what you really wanted   You could use this method    public static String getCallerCallerClassName          StackTraceElement   stElements   Thread currentThread   getStackTrace        String callerClassName   null      for  int i 1  i lt stElements length  i              StackTraceElement ste   stElements i           if   ste getClassName   equals KDebug class getName    amp  amp  ste getClassName   indexOf  java lang Thread    0                if  callerClassName  null                    callerClassName   ste getClassName                  else if   callerClassName equals ste getClassName                       return ste getClassName                                      return null       Is that for debugging   If not  there may be a better solution to your problem

User · Answer

StackTrace  This Highly depends on what you are looking for    But this should get the class and method that called this method within this object directly    index 0   Thread index 1   this index 2   direct caller  can be self  index 3     n   classes and methods that called each other to get to the index 2 and below    For Class Method File name   Thread currentThread   getStackTrace   2  getClassName    Thread currentThread   getStackTrace   2  getMethodName    Thread currentThread   getStackTrace   2  getFileName      For Class   Class forName Thread currentThread   getStackTrace   2  getClassName      FYI  Class forName   throws a ClassNotFoundException which is NOT runtime  Youll need try catch   Also  if you are looking to ignore the calls within the class itself  you have to add some looping with logic to check for that particular thing   Something like     I have not tested this piece of code so beware   StackTraceElement   stes   Thread currentThread   getStackTrace    for int i 2 i lt stes length i      if  stes i  getClassName   equals this getClass   getName         return stes i  getClassName        StackWalker  StackWalker StackFrame  Note that this is not an extensive guide but an example of the possibility   Prints the Class of each StackFrame  by grabbing the Class reference   StackWalker getInstance Option RETAIN CLASS REFERENCE       forEach frame - gt  System out println frame getDeclaringClass        Does the same thing but first collects the stream into a List  Just for demonstration purposes   StackWalker getInstance Option RETAIN CLASS REFERENCE       walk stream - gt  stream collect Collectors toList          forEach frame - gt  System out println frame getDeclaringClass

User · Answer

I know this is an old question but I believed the asker wanted the class  not the class name  I wrote a little method that will get the actual class  It is sort of cheaty and may not always work  but sometimes when you need the actual class  you will have to use this method                Get the caller class          param level The level of the caller class                      For example  If you are calling this class inside a method and you want to get the caller class of that method                                   you would use level 2  If you want the caller of that class  you would use level 3                             Usually level 2 is the one you want          return The caller class          throws ClassNotFoundException We failed to find the caller class              public static Class getCallerClass int level  throws ClassNotFoundException           StackTraceElement   stElements   Thread currentThread   getStackTrace            String rawFQN   stElements level 1  toString   split        0           return Class forName rawFQN substring 0  rawFQN lastIndexOf

User · Answer

SecurityManager has a protected method getClassContext  By creating a utility class which extends SecurityManager  you can access this   public class CallingClass extends SecurityManager       public static final CallingClass INSTANCE   new CallingClass         public Class   getCallingClasses             return getClassContext              Use CallingClass INSTANCE getCallingClasses   to retrieve the calling classes   There is also a small library  disclaimer  mine  WhoCalled which exposes this information  It uses Reflection getCallerClass when available  else falls back to SecurityManager

[java] How to get the caller class in Java

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