我需要找到一个方法的调用者。是否可以使用堆栈跟踪或反射?


当前回答

简单回答ReflectionUtils.getCallingClass(0)

长答案(代码,Groovy)

package my

import org.codehaus.groovy.reflection.ReflectionUtils
import java.lang.reflect.Field
import java.lang.reflect.Method

trait Reflector {

    static String[] fieldNames() {
        List<String> names = []
        Arrays.asList(naturalFields()).forEach { Field fl -> names.add(fl.name) }
        return names.toArray() as String[]
    }

    static Field[] naturalFields() {
        return finalClass().getDeclaredFields().findAll { Field fl -> !fl.synthetic }.collect()
    }

    static Method[] naturalMethods() {
        return finalClass().getDeclaredMethods().findAll { Method md -> !md.synthetic }.collect()
    }

    static Class finalClass() {
        return ReflectionUtils.getCallingClass(0)
    }

}

class Demo implements Reflector {

    int archived = 0
    int demo = 100

    static void playToo() {
        println finalClass()
    }

}

println Demo.finalClass() // class my.Demo
println Demo.naturalFields() // [private int my.Demo.archived, private int my.Demo.demo]
println Demo.fieldNames() // [archived, demo]

其他回答

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.PrintWriter;

class DBConnection {
    String createdBy = null;

    DBConnection(Throwable whoCreatedMe) {
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        PrintWriter pw = new PrintWriter(os);
        whoCreatedMe.printStackTrace(pw);
        try {
            createdBy = os.toString();
            pw.close();
            os.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

public class ThrowableTest {

    public static void main(String[] args) {

        Throwable createdBy = new Throwable(
                "Connection created from DBConnectionManager");
        DBConnection conn = new DBConnection(createdBy);
        System.out.println(conn.createdBy);
    }
}

OR

public static interface ICallback<T> { T doOperation(); }


public class TestCallerOfMethod {

    public static <T> T callTwo(final ICallback<T> c){
        // Pass the object created at callee to the caller
        // From the passed object we can get; what is the callee name like below.
        System.out.println(c.getClass().getEnclosingMethod().getName());
        return c.doOperation();
    }

    public static boolean callOne(){
        ICallback callBackInstance = new ICallback(Boolean){
            @Override
            public Boolean doOperation() 
            {
                return true;
            }
        };
        return callTwo(callBackInstance);
    }

    public static void main(String[] args) {
         callOne();
    }
}

简单回答ReflectionUtils.getCallingClass(0)

长答案(代码,Groovy)

package my

import org.codehaus.groovy.reflection.ReflectionUtils
import java.lang.reflect.Field
import java.lang.reflect.Method

trait Reflector {

    static String[] fieldNames() {
        List<String> names = []
        Arrays.asList(naturalFields()).forEach { Field fl -> names.add(fl.name) }
        return names.toArray() as String[]
    }

    static Field[] naturalFields() {
        return finalClass().getDeclaredFields().findAll { Field fl -> !fl.synthetic }.collect()
    }

    static Method[] naturalMethods() {
        return finalClass().getDeclaredMethods().findAll { Method md -> !md.synthetic }.collect()
    }

    static Class finalClass() {
        return ReflectionUtils.getCallingClass(0)
    }

}

class Demo implements Reflector {

    int archived = 0
    int demo = 100

    static void playToo() {
        println finalClass()
    }

}

println Demo.finalClass() // class my.Demo
println Demo.naturalFields() // [private int my.Demo.archived, private int my.Demo.demo]
println Demo.fieldNames() // [archived, demo]

听起来好像您试图避免将this的引用传递到方法中。传递这个比通过当前堆栈跟踪查找调用者要好得多。重构为更面向对象的设计更好。你不需要认识打电话的人。必要时传递回调对象。

下面是我根据本主题中显示的提示制作的部分代码。 希望能有所帮助。

(请随时提出任何建议来改进此代码,请告诉我)

柜台:

public class InstanceCount{
    private static Map<Integer, CounterInstanceLog> instanceMap = new HashMap<Integer, CounterInstanceLog>();
private CounterInstanceLog counterInstanceLog;


    public void count() {
        counterInstanceLog= new counterInstanceLog();
    if(counterInstanceLog.getIdHashCode() != 0){
    try {
        if (instanceMap .containsKey(counterInstanceLog.getIdHashCode())) {
         counterInstanceLog= instanceMap .get(counterInstanceLog.getIdHashCode());
    }

    counterInstanceLog.incrementCounter();

            instanceMap .put(counterInstanceLog.getIdHashCode(), counterInstanceLog);
    }

    (...)
}

对象是:

public class CounterInstanceLog{
    private int idHashCode;
    private StackTraceElement[] arrayStackTraceElements;
    private int instanceCount;
    private String callerClassName;

    private StackTraceElement getProjectClasses(int depth) {
      if(depth< 10){
        getCallerClassName(sun.reflect.Reflection.getCallerClass(depth).getName());
        if(getCallerClassName().startsWith("com.yourproject.model")){
            setStackTraceElements(Thread.currentThread().getStackTrace());
            setIdHashCode();
        return arrayStackTraceElements[depth];
        }
        //+2 because one new item are added to the stackflow
        return getProjectClasses(profundidade+2);           
      }else{
        return null;
      }
    }

    private void setIdHashCode() {
        if(getNomeClasse() != null){
            this.idHashCode = (getCallerClassName()).hashCode();
        }
    }

    public void incrementaContador() {
    this.instanceCount++;
}

    //getters and setters

    (...)



}
private void parseExceptionContents(
      final Exception exception,
      final OutputStream out)
   {
      final StackTraceElement[] stackTrace = exception.getStackTrace();
      int index = 0;
      for (StackTraceElement element : stackTrace)
      {
         final String exceptionMsg =
              "Exception thrown from " + element.getMethodName()
            + " in class " + element.getClassName() + " [on line number "
            + element.getLineNumber() + " of file " + element.getFileName() + "]";
         try
         {
            out.write((headerLine + newLine).getBytes());
            out.write((headerTitlePortion + index++ + newLine).getBytes() );
            out.write((headerLine + newLine).getBytes());
            out.write((exceptionMsg + newLine + newLine).getBytes());
            out.write(
               ("Exception.toString: " + element.toString() + newLine).getBytes());
         }
         catch (IOException ioEx)
         {
            System.err.println(
                 "IOException encountered while trying to write "
               + "StackTraceElement data to provided OutputStream.\n"
               + ioEx.getMessage() );
         }
      }
   }