Revert "BAEL-4134"

core-java-modules/core-java-exceptions-2/src/test/java/com/baeldung/exceptionininitializererror/ExceptionInInitializerErrorUnitTest.java

@@ -0,0 +1,55 @@
+package com.baeldung.exceptionininitializererror;
+
+import org.junit.Test;
+
+import java.lang.reflect.Constructor;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+public class ExceptionInInitializerErrorUnitTest {
+
+    @Test
+    public void givenStaticVar_whenThrows_thenWrapsItInAnExceptionInInitializerError() {
+        assertThatThrownBy(StaticVar::new)
+          .isInstanceOf(ExceptionInInitializerError.class)
+          .hasCauseInstanceOf(RuntimeException.class);
+    }
+
+    @Test
+    public void givenStaticBlock_whenThrows_thenWrapsItInAnExceptionInInitializerError() {
+        assertThatThrownBy(StaticBlock::new)
+          .isInstanceOf(ExceptionInInitializerError.class)
+          .hasCauseInstanceOf(ArithmeticException.class);
+    }
+
+    private static class CheckedConvention {
+
+        private static Constructor<?> constructor;
+
+        static {
+            try {
+                constructor = CheckedConvention.class.getDeclaredConstructor();
+            } catch (NoSuchMethodException e) {
+                throw new ExceptionInInitializerError(e);
+            }
+        }
+    }
+
+    private static class StaticVar {
+
+        private static int state = initializeState();
+
+        private static int initializeState() {
+            throw new RuntimeException();
+        }
+    }
+
+    private static class StaticBlock {
+
+        private static int state;
+
+        static {
+            state = 42 / 0;
+        }
+    }
+}

core-java-modules/core-java-exceptions-2/src/test/java/com/baeldung/exceptions/TooManyOpenFilesExceptionLiveTest.java

@@ -0,0 +1,87 @@
+package com.baeldung.exceptions;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.AfterEach;
+
+
+public class TooManyOpenFilesExceptionLiveTest {
+
+    //This is not a regular UnitTest due to the fact that it depends on System.gc() to work properly.
+    //As we have to force the JVM to run out of file descriptors, any other tests that uses IO may fail.
+    //This may indirectly affect other tests that are part of the Jenkins Build.
+
+    private File tempFile;
+
+    @BeforeEach
+    public void setUp() throws IOException {
+        tempFile = File.createTempFile("testForException", "tmp");
+    }
+
+    @AfterEach
+    public void tearDown() {
+        //Enforce a GC to clear unreferenced files and release descriptors
+        System.gc();
+        tempFile.delete();
+    }
+
+    @Test
+    public void whenNotClosingResoures_thenIOExceptionShouldBeThrown() {
+        try {
+            for (int x = 0; x < 1000000; x++) {
+                FileInputStream leakyHandle = new FileInputStream(tempFile);
+            }
+            Assertions.fail("Method Should Have Failed");
+        } catch (IOException e) {
+            assertTrue(e.getMessage().toLowerCase().contains("too many open files"));
+        } catch (Exception e) {
+            Assertions.fail("Unexpected exception");
+        }
+    }
+
+    @Test
+    public void whenClosingResoures_thenIOExceptionShouldNotBeThrown() {
+        try {
+            for (int x = 0; x < 1000000; x++) {
+                FileInputStream nonLeakyHandle = null;
+                try {
+                    nonLeakyHandle = new FileInputStream(tempFile);
+                } finally {
+                    if (nonLeakyHandle != null) {
+                        nonLeakyHandle.close();
+                    }
+                }
+            }
+        } catch (IOException e) {
+            assertFalse(e.getMessage().toLowerCase().contains("too many open files"));
+            Assertions.fail("Method Should Not Have Failed");
+        } catch (Exception e) {
+            Assertions.fail("Unexpected exception");
+        }
+    }
+
+    @Test
+    public void whenUsingTryWithResoures_thenIOExceptionShouldNotBeThrown() {
+        try {
+            for (int x = 0; x < 1000000; x++) {
+                try (FileInputStream nonLeakyHandle = new FileInputStream(tempFile)) {
+                    //Do something with the file
+                }
+            }
+        } catch (IOException e) {
+            assertFalse(e.getMessage().toLowerCase().contains("too many open files"));
+            Assertions.fail("Method Should Not Have Failed");
+        } catch (Exception e) {
+            Assertions.fail("Unexpected exception");
+        }
+    }
+}