added InputStream to String examples

Author: eugenp

core-java/src/test/java/org/baeldung/java/CoreJavaIoUnitTest.java

@@ -2,14 +2,17 @@
 
 import static org.apache.commons.lang3.RandomStringUtils.randomAlphabetic;
 import static org.hamcrest.Matchers.equalTo;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThat;
 
+import java.io.BufferedReader;
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.Reader;
 import java.io.StringWriter;
+import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.util.Scanner;
 
@@ -24,12 +27,32 @@
 
 public class CoreJavaIoUnitTest {
     protected final Logger logger = LoggerFactory.getLogger(getClass());
+    private static final int DEFAULT_SIZE = 150000000;
+
+    // private static final int DEFAULT_SIZE = 8;
 
     // tests - InputStream to String
 
+    // 11s
+    @Test
+    public void givenUsingJava5_whenConvertingAnInputStreamToAString_thenCorrect() throws IOException {
+        final String originalString = randomAlphabetic(DEFAULT_SIZE);
+        final InputStream inputStream = new ByteArrayInputStream(originalString.getBytes());
+
+        final StringBuilder textBuilder = new StringBuilder();
+        try (Reader reader = new BufferedReader(new InputStreamReader(inputStream, Charset.forName(StandardCharsets.UTF_8.name())))) {
+            int c = 0;
+            while ((c = reader.read()) != -1) {
+                textBuilder.append((char) c);
+            }
+        }
+        assertEquals(textBuilder.toString(), originalString);
+    }
+
+    // 8s
     @Test
     public final void givenUsingJava7_whenConvertingAnInputStreamToAString_thenCorrect() throws IOException {
-        final String originalString = randomAlphabetic(8);
+        final String originalString = randomAlphabetic(DEFAULT_SIZE);
         final InputStream inputStream = new ByteArrayInputStream(originalString.getBytes()); // exampleString.getBytes(StandardCharsets.UTF_8);
 
         // When
@@ -43,7 +66,7 @@ public final void givenUsingJava7_whenConvertingAnInputStreamToAString_thenCorre
 
     @Test
     public final void givenUsingGuava_whenConvertingAnInputStreamToAString_thenCorrect() throws IOException {
-        final String originalString = randomAlphabetic(8);
+        final String originalString = randomAlphabetic(DEFAULT_SIZE);
         final InputStream inputStream = new ByteArrayInputStream(originalString.getBytes());
 
         final InputSupplier<InputStream> inputSupplier = new InputSupplier<InputStream>() {
@@ -62,7 +85,7 @@ public final InputStream getInput() throws IOException {
 
     @Test
     public final void givenUsingGuavaAndJava7_whenConvertingAnInputStreamToAString_thenCorrect() throws IOException {
-        final String originalString = randomAlphabetic(8);
+        final String originalString = randomAlphabetic(DEFAULT_SIZE);
         final InputStream inputStream = new ByteArrayInputStream(originalString.getBytes());
 
         // When
@@ -76,7 +99,7 @@ public final void givenUsingGuavaAndJava7_whenConvertingAnInputStreamToAString_t
 
     @Test
     public final void givenUsingCommonsIo_whenConvertingAnInputStreamToAString_thenCorrect() throws IOException {
-        final String originalString = randomAlphabetic(8);
+        final String originalString = randomAlphabetic(DEFAULT_SIZE);
         final InputStream inputStream = new ByteArrayInputStream(originalString.getBytes());
 
         // When
@@ -86,7 +109,7 @@ public final void givenUsingCommonsIo_whenConvertingAnInputStreamToAString_thenC
 
     @Test
     public final void givenUsingCommonsIoWithCopy_whenConvertingAnInputStreamToAString_thenCorrect() throws IOException {
-        final String originalString = randomAlphabetic(8);
+        final String originalString = randomAlphabetic(DEFAULT_SIZE);
         final InputStream inputStream = new ByteArrayInputStream(originalString.getBytes());
 
         // When