BAEL - 971 Code Changes (#2492)

* BAEL-971 Code

BAEL-  971 Introduction to Apache Commons Lang3 code

* BAEL - 971 Code

BAEL - 971 : Introduction to Apache Commons Lang3

* Updated the commons.lang version from V3.5 to V3.6

libraries/src/test/java/com/baeldung/commons/lang3/Lang3UtilsTest.java

@@ -0,0 +1,118 @@
+package com.baeldung.commons.lang3;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotSame;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.beans.PropertyChangeEvent;
+import java.beans.PropertyChangeListener;
+import java.io.File;
+import java.lang.reflect.Field;
+import java.util.Locale;
+import java.util.concurrent.Future;
+
+import org.apache.commons.lang3.ArchUtils;
+import org.apache.commons.lang3.BooleanUtils;
+import org.apache.commons.lang3.SystemUtils;
+import org.apache.commons.lang3.arch.Processor;
+import org.apache.commons.lang3.concurrent.ConcurrentRuntimeException;
+import org.apache.commons.lang3.concurrent.ConcurrentUtils;
+import org.apache.commons.lang3.event.EventUtils;
+import org.apache.commons.lang3.reflect.FieldUtils;
+import org.apache.commons.lang3.time.FastDateFormat;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class Lang3UtilsTest {
+
+    @Test
+    public void test_to_Boolean_fromString() {
+        assertFalse(BooleanUtils.toBoolean("off"));
+        assertTrue(BooleanUtils.toBoolean("true"));
+        assertTrue(BooleanUtils.toBoolean("tRue"));
+        assertFalse(BooleanUtils.toBoolean("no"));
+        assertFalse(BooleanUtils.isTrue(Boolean.FALSE));
+        assertFalse(BooleanUtils.isTrue(null));
+    }
+
+    @Test
+    public void testGetUserHome() {
+        final File dir = SystemUtils.getUserHome();
+        Assert.assertNotNull(dir);
+        Assert.assertTrue(dir.exists());
+    }
+
+    @Test
+    public void testGetJavaHome() {
+        final File dir = SystemUtils.getJavaHome();
+        Assert.assertNotNull(dir);
+        Assert.assertTrue(dir.exists());
+    }
+
+    @Test
+    public void testProcessorArchType() {
+        Processor processor = ArchUtils.getProcessor("x86");
+        assertTrue(processor.is32Bit());
+        assertFalse(processor.is64Bit());
+    }
+
+    @Test
+    public void testProcessorArchType64Bit() {
+        Processor processor = ArchUtils.getProcessor("x86_64");
+        assertFalse(processor.is32Bit());
+        assertTrue(processor.is64Bit());
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testConcurrentRuntimeExceptionCauseError() {
+        new ConcurrentRuntimeException("An error", new Error());
+    }
+
+    @Test
+    public void testConstantFuture_Integer() throws Exception {
+        Future<Integer> test = ConcurrentUtils.constantFuture(5);
+        assertTrue(test.isDone());
+        assertSame(5, test.get());
+        assertFalse(test.isCancelled());
+    }
+
+    @Test
+    public void testFieldUtilsGetAllFields() {
+        final Field[] fieldsNumber = Number.class.getDeclaredFields();
+        assertArrayEquals(fieldsNumber, FieldUtils.getAllFields(Number.class));
+    }
+
+    @Test
+    public void test_getInstance_String_Locale() {
+        final FastDateFormat format1 = FastDateFormat.getInstance("MM/DD/yyyy", Locale.US);
+        final FastDateFormat format3 = FastDateFormat.getInstance("MM/DD/yyyy", Locale.GERMANY);
+
+        assertNotSame(format1, format3);
+    }
+
+    @Test
+    public void testAddEventListenerThrowsException() {
+        final ExceptionEventSource src = new ExceptionEventSource();
+        try {
+            EventUtils.addEventListener(src, PropertyChangeListener.class, new PropertyChangeListener() {
+                @Override
+                public void propertyChange(final PropertyChangeEvent e) {
+                    // Do nothing!
+                }
+            });
+            fail("Add method should have thrown an exception, so method should fail.");
+        } catch (final RuntimeException e) {
+
+        }
+    }
+
+    public static class ExceptionEventSource {
+        public void addPropertyChangeListener(final PropertyChangeListener listener) {
+            throw new RuntimeException();
+        }
+    }
+
+}