Changeset 32608 for main

Timestamp:

2018-11-16T14:24:39+13:00 (5 years ago)

Author:

ak19

Message:

Copying the methods printing out the caller (callstack) information from gli's Utility.java into core's Misc.java.

File:

• main/trunk/greenstone3/src/java/org/greenstone/util/Misc.java (modified) (1 diff)

main/trunk/greenstone3/src/java/org/greenstone/util/Misc.java

@@ -66 +66 @@
     }  
     }
+
+    
+    /** 
+     * Handy function to display the list of calling functions by
+     * printing out the stack trace even when you don't have an exception
+     */
+    static public void printStackTrace() {
+    // https://stackoverflow.com/questions/1069066/get-current-stack-trace-in-java
+    
+    //Thread.dumpStack(); // looks too much like an exception, though the newlines separating each function call is handy
+    //new Exception().printStackTrace(); // outputs in the format of an exception too   
+    //System.err.println("\n@@@@ stacktrace:\n" + Arrays.toString(Thread.currentThread().getStackTrace()) + "\n"); // outputs all in one line
+    
+    System.err.println("\n@@@@ stacktrace:");
+    StackTraceElement[] els = new Throwable().getStackTrace(); // starts at index 1, which is this function
+    //StackTraceElement[] els = Thread.currentThread().getStackTrace(); starts at index 0, "java.lang.Thread.getStackTrace()"
+    for(StackTraceElement ste : els) {
+        System.err.println("   " + ste);
+    }
+    }
+    
+    /** 
+     * Handy function to display the parent of the calling function
+     * (the function that called the function that called printCaller())
+     */
+    static public void printCaller() {
+    int parent = 1;
+    // this function printCaller() itself adds another layer on the callstack since
+    // it calls the overloaded method, so need to add 1 more to parent
+    printCaller(parent++); 
+    }
+    
+    /** 
+     * Handy function to display the nth ancestor of the calling function
+     * where ancestor=0 would be the calling function itself
+     */
+    static public void printCaller(int ancestor) {
+    // https://stackoverflow.com/questions/1069066/get-current-stack-trace-in-java
+    
+    // Thread.currentThread().getStackTrace() starts at index 0: "java.lang.Thread.getStackTrace()"
+    // index 1 will be this method (printCaller) and index 2 will be the calling function itself who wants
+    // to know who called it. So need to at least start at index 3 to get informative caller information
+    
+    StackTraceElement[] callstack = Thread.currentThread().getStackTrace();
+    StackTraceElement requestor = callstack[2]; // the calling function, the function that called this one
+    StackTraceElement caller_requested = callstack[ancestor+3]; // the function requested
+    System.err.println("@@@ Function " + requestor +  " called by:\n    "
+               + caller_requested + " at " + ancestor + " ancestors back");
+    }    
+    
     
     /** Method to determine if the host system is Windows based.