Java stacktraces

java-exception-stacktraces/pom.xml

@@ -0,0 +1,48 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.pivovarit</groupId>
+    <version>1.0</version>
+    <artifactId>java-exception-stacktraces</artifactId>
+
+    <name>java-exception-stacktraces</name>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>21</source>
+                    <target>21</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>2.19.1</version>
+                <dependencies>
+                    <dependency>
+                        <groupId>org.junit.platform</groupId>
+                        <artifactId>junit-platform-surefire-provider</artifactId>
+                        <version>1.1.0</version>
+                    </dependency>
+                </dependencies>
+            </plugin>
+        </plugins>
+    </build>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <version>5.10.2</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>3.22.0</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

java-exception-stacktraces/src/main/java/com/pivovarit/exception/ExceptionCacheExample.java

@@ -0,0 +1,23 @@
+package com.pivovarit.exception;
+
+import java.util.Collections;
+import java.util.IdentityHashMap;
+
+class ExceptionCacheExample {
+
+    public static void main(String[] args) {
+        var exceptions = Collections.newSetFromMap(new IdentityHashMap<>());
+
+        String foo = null;
+        for (int i = 0; i < Integer.MAX_VALUE; i++) {
+            try {
+                foo.toUpperCase();
+            } catch (NullPointerException e) {
+                exceptions.add(e);
+            }
+        }
+        99327
+
+        System.out.println(exceptions.size());
+    }
+}

java-exception-stacktraces/src/main/java/com/pivovarit/exception/StacktraceDropExample.java

@@ -0,0 +1,28 @@
+package com.pivovarit.exception;
+
+import java.util.Arrays;
+import java.util.concurrent.atomic.AtomicReference;
+
+class StacktraceDropExample {
+
+    public static void main(String[] args) {
+        var previous = new AtomicReference<NullPointerException>();
+
+        String foo = null;
+        for (int i = 0; i < Integer.MAX_VALUE; i++) {
+            try {
+                foo.toUpperCase();
+            } catch (NullPointerException e) {
+                if (e.getStackTrace().length == 0) {
+                    System.out.printf("Stacktrace dropped at iteration %d%n", i);
+                    System.out.printf("Last stacktrace: %s%n",
+                      Arrays.toString(previous.get().getStackTrace()));
+                    System.out.printf("New stacktrace: %s%n",
+                      Arrays.toString(e.getStackTrace()));
+                    return;
+                }
+                previous.set(e);
+            }
+        }
+    }
+}

java-exception-stacktraces/src/main/java/com/pivovarit/exception/StaticStacklessExceptionExample.java

@@ -0,0 +1,14 @@
+package com.pivovarit.exception;
+
+class StaticStacklessExceptionExample {
+
+    private static final NullPointerException NULL_POINTER_EXCEPTION = new NullPointerException();
+
+    static {
+        NULL_POINTER_EXCEPTION.setStackTrace(new StackTraceElement[0]);
+    }
+
+    public static void main(String[] args) {
+        throw NULL_POINTER_EXCEPTION;
+    }
+}

pom.xml

@@ -14,6 +14,7 @@
         <module>kotlin-collections</module>
         <module>hamming-error-correction</module>
         <module>kotlin-type-inference</module>
+        <module>java-exception-stacktraces</module>
         <module>java-sneaky-throws-lambda</module>
         <module>java-priorityqueue-stream-order</module>
         <module>java-stream-mapmulti</module>