BAEL-608 - Introduction to Java9 StackWalking AP (eugenp#1329)

yasin3061 · maibin · commit 00d42129ef50 · 2017-03-09T08:50:23.000+01:00
* yasin.bhojawala@gmail.com Evaluation article on Different Types of Bean Injection in Spring * Revert "yasin.bhojawala@gmail.com" This reverts commit 963cc51. * Fixing compilation error and removing unused import * Introduction to Java9 StackWalking API - yasin.bhojawala@gmail.com Code examples for the article "Introduction to Java9 StackWalking API" * BAEL-608 Introduction to Java9 StackWalking API * BAEL-608 Introduction to Java9 StackWalking API changing the test names to BDD style * BAEL-608 Introduction to Java9 StackWalking API correcting the typo * BAEL-608 Introduction to Java9 StackWalking API improving method names * BAEL-608 Introduction to Java9 StackWalking API test method names improvements
diff --git a/core-java-9/src/main/java/com/baeldung/java9/stackwalker/StackWalkerDemo.java b/core-java-9/src/main/java/com/baeldung/java9/stackwalker/StackWalkerDemo.java
@@ -16,48 +16,68 @@ public void methodTwo() {
     }
 
     public void methodThree() {
-        List<StackFrame> stackTrace = StackWalker.getInstance(StackWalker.Option.RETAIN_CLASS_REFERENCE)
-            .walk(StackWalkerDemo::walkExample);
+        List<StackFrame> stackTrace = StackWalker.getInstance()
+            .walk(this::walkExample);
 
         printStackTrace(stackTrace);
 
         System.out.println("---------------------------------------------");
 
-        stackTrace = StackWalker.getInstance(StackWalker.Option.RETAIN_CLASS_REFERENCE)
-            .walk(StackWalkerDemo::walkExample2);
+        stackTrace = StackWalker.getInstance()
+            .walk(this::walkExample2);
 
         printStackTrace(stackTrace);
 
         System.out.println("---------------------------------------------");
 
-        String line = StackWalker.getInstance()
-            .walk(StackWalkerDemo::walkExample3);
+        String line = StackWalker.getInstance().walk(this::walkExample3);
         System.out.println(line);
+
+        System.out.println("---------------------------------------------");
+        
+        stackTrace = StackWalker.getInstance(StackWalker.Option.SHOW_REFLECT_FRAMES)
+            .walk(this::walkExample);
+
+        printStackTrace(stackTrace);
+        
+        System.out.println("---------------------------------------------");
+        
+        Runnable r = () -> {
+            List<StackFrame> stackTrace2 = StackWalker.getInstance(StackWalker.Option.SHOW_HIDDEN_FRAMES)
+                .walk(this::walkExample);
+            printStackTrace(stackTrace2);
+        };
+        r.run();
     }
 
-    private static List<StackFrame> walkExample(Stream<StackFrame> stackFrameStream) {
+    public List<StackFrame> walkExample(Stream<StackFrame> stackFrameStream) {
         return stackFrameStream.collect(Collectors.toList());
     }
 
-    private static List<StackFrame> walkExample2(Stream<StackFrame> stackFrameStream) {
+    public List<StackFrame> walkExample2(Stream<StackFrame> stackFrameStream) {
         return stackFrameStream.filter(frame -> frame.getClassName()
             .contains("com.baeldung"))
             .collect(Collectors.toList());
     }
 
-    private static String walkExample3(Stream<StackFrame> stackFrameStream) {
+    public String walkExample3(Stream<StackFrame> stackFrameStream) {
         return stackFrameStream.filter(frame -> frame.getClassName()
             .contains("com.baeldung")
             && frame.getClassName()
-                .endsWith("Test"))
+            .endsWith("Test"))
             .findFirst()
             .map(frame -> frame.getClassName() + "#" + frame.getMethodName() + ", Line " + frame.getLineNumber())
             .orElse("Unknown caller");
     }
+    
+    public void findCaller() {
+        Class<?> caller = StackWalker.getInstance(StackWalker.Option.RETAIN_CLASS_REFERENCE).getCallerClass();
+        System.out.println(caller.getCanonicalName());
+    }
 
-    private void printStackTrace(List<StackFrame> stackTrace) {
+    public void printStackTrace(List<StackFrame> stackTrace) {
         for (StackFrame stackFrame : stackTrace) {
-            System.out.println(stackFrame.getDeclaringClass()
+            System.out.println(stackFrame.getClassName()
                 .toString() + "#" + stackFrame.getMethodName() + ", Line " + stackFrame.getLineNumber());
         }
     }
diff --git a/core-java-9/src/test/java/com/baeldung/java9/stackwalker/StackWalkerDemoTest.java b/core-java-9/src/test/java/com/baeldung/java9/stackwalker/StackWalkerDemoTest.java
@@ -5,7 +5,12 @@
 public class StackWalkerDemoTest {
 
     @Test
-    public void walkTheStack() {
+    public void giveStalkWalker_whenWalkingTheStack_thenShowStackFrames() {
         new StackWalkerDemo().methodOne();
     }
+    
+    @Test
+    public void giveStalkWalker_whenInvokingFindCaller_thenFindCallingClass() {
+        new StackWalkerDemo().findCaller();
+    }
 }

Original file line number	Diff line number	Diff line change
`@@ -5,7 +5,12 @@`
`5`	`5`	`public class StackWalkerDemoTest {`
`6`	`6`
`7`	`7`	`@Test`
`8`		`- public void walkTheStack() {`
	`8`	`+ public void giveStalkWalker_whenWalkingTheStack_thenShowStackFrames() {`
`9`	`9`	`new StackWalkerDemo().methodOne();`
`10`	`10`	`}`
	`11`	`+`
	`12`	`+ @Test`
	`13`	`+ public void giveStalkWalker_whenInvokingFindCaller_thenFindCallingClass() {`
	`14`	`+ new StackWalkerDemo().findCaller();`
	`15`	`+ }`
`11`	`16`	`}`