org.unix4j.util.StackTraceUtil Maven / Gradle / Ivy
package org.unix4j.util;
/**
* Utility class to evaluate the {@link StackTraceElement} corresponding to a
* calling method in the caller stack.
*/
public class StackTraceUtil {
/**
* Returns the stack trace element corresponding to the direct caller
* method, that is, the method which calls this method.
*/
public static StackTraceElement getCurrentMethodStackTraceElement() {
return internalGetCurrentMethodStackTraceElement(1);
}
/**
* Returns the stack trace element belonging to the
* callerOffsetth caller of the calling method.
*
* For example, {@code callerOffset=0} returns the stack trace element of
* the direct caller of this method; {@code callerOffset=1} corresponds to
* the method calling the direct caller method, etc.
*
* @param callerOffset
* the index of the stack trace element in the caller stack,
* where {@code callerOffset=0} corresponds to the direct caller
* of this method
*/
public static StackTraceElement getCurrentMethodStackTraceElement(int callerOffset) {
return internalGetCurrentMethodStackTraceElement(callerOffset + 1);
}
private static StackTraceElement internalGetCurrentMethodStackTraceElement(int callerOffset) {
// trc[0] Thread.dumpThreads(native)
// trc[1] Thread.getStackTrace(..)
// trc[2] StackTrace.internalGetCurrentMethodStackTraceElement(..)
// trc[3] is what we want for offset == 0!
// NOTE sometimes also
// trc[0] Thread.getStackTrace(..)
// trc[1] StackTrace.internalGetCurrentMethodStackTraceElement(..)
// trc[2] is what we want for offset == 0!
StackTraceElement[] trc = Thread.currentThread().getStackTrace();
for (int i = 0; i < trc.length; i++) {
if (trc[i].getClassName().equals(StackTraceUtil.class.getName()) && trc[i].getMethodName().equals("internalGetCurrentMethodStackTraceElement")) {
return trc[callerOffset + i + 1];
}
}
throw new RuntimeException("internal error: current method not found");
}
// no instances
private StackTraceUtil() {
}
}