Add Java 18 test class ...

- UTF-8 by Default
- Deprecated Method finalize()
- Simple Web Server
- Internet-Address Resolution SPI
- Code Snippets in Java API Documentation

Author: mperor

README.md

@@ -29,5 +29,6 @@ This project includes unit tests for key functionalities introduced in each Java
 - [Java 15](src/test/java/pl/mperor/lab/java/Java15.java)
 - [Java 16](src/test/java/pl/mperor/lab/java/Java16.java)
 - [Java 17](src/test/java/pl/mperor/lab/java/Java17.java)
+- [Java 18](src/test/java/pl/mperor/lab/java/Java18.java)
 
 For detailed examples and tests of each feature, please refer to the individual source files linked above.

build.gradle

@@ -23,4 +23,8 @@ test {
 
 tasks.withType(JavaCompile) {
     options.encoding = 'UTF-8'
+}
+
+tasks.withType(Test) {
+    jvmArgs("-Dfile.encoding=UTF-8")
 }

src/test/java/pl/mperor/lab/java/Java18.java

@@ -0,0 +1,107 @@
+package pl.mperor.lab.java;
+
+import com.sun.net.httpserver.HttpServer;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import pl.mperor.lab.TestUtils;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.UnknownHostException;
+import java.nio.charset.Charset;
+
+/**
+ * Java 18 (March 2022)
+ */
+public class Java18 {
+
+    @Test
+    public void testDefaultCharsetIsUTF8() throws IOException {
+        System.out.printf("Running Java Version: %d, file.encoding=%s, native.encoding=%s%n",
+                Runtime.version().feature(),
+                System.getProperty("file.encoding"),
+                System.getProperty("native.encoding")
+        );
+
+        Charset defaultCharset = Charset.defaultCharset();
+        Assertions.assertEquals("UTF-8", defaultCharset.name());
+
+        var utf8Reader = new BufferedReader(new InputStreamReader(ClassLoader.getSystemResourceAsStream("encoding/fileUTF8.txt")));
+        var win1250Reader = new BufferedReader(new InputStreamReader(ClassLoader.getSystemResourceAsStream("encoding/fileWin1250.txt"), Charset.forName("windows-1250")));
+
+        try (utf8Reader; win1250Reader) {
+            Assertions.assertEquals(utf8Reader.readLine(), win1250Reader.readLine());
+        }
+    }
+
+    @Test
+    public void testSimpleWebServer() throws IOException, InterruptedException {
+        HttpServer server = HttpServer.create(new InetSocketAddress(9000), 0);
+        server.createContext("/hello", exchange -> {
+            String response = "Hello World!";
+            exchange.sendResponseHeaders(200, response.getBytes().length);
+            try (OutputStream os = exchange.getResponseBody()) {
+                os.write(response.getBytes());
+            }
+        });
+        server.start();
+        Assertions.assertNotNull(server);
+        Assertions.assertEquals("Hello World!", curlResponse("http://127.0.0.1:9000/hello"));
+
+        server.stop(0);
+    }
+
+    private static String curlResponse(String url) throws IOException, InterruptedException {
+        var curlProcess = new ProcessBuilder("curl", url).start();
+        String result;
+        try (var reader = curlProcess.inputReader()) {
+            result = reader.readLine();
+        }
+        curlProcess.waitFor();
+        curlProcess.destroy();
+        return result;
+    }
+
+    @SuppressWarnings("removal")
+    @Test
+    public void testFinalizeDeprecated() throws Throwable {
+        var out = TestUtils.setTempSystemOut();
+
+        // warning: finalize() in Object has been deprecated and marked for removal
+        var object = new Object() {
+            @Override
+            protected void finalize() throws Throwable {
+                super.finalize();
+                System.out.print("finalizing ...");
+            }
+        };
+        object.finalize();
+        Assertions.assertEquals("finalizing ...", out.all());
+        TestUtils.resetSystemOut();
+    }
+
+    @Test
+    public void testInetAddressResolution() throws UnknownHostException {
+        InetAddress address = InetAddress.getByName("localhost");
+        Assertions.assertTrue(address.isLoopbackAddress());
+    }
+
+    @Test
+    public void testSnippet() {
+        Assertions.assertNotNull(new JavadocSample());
+    }
+
+    /**
+     * This is a doc for {@code JavadocSample}.
+     * Code snippet:
+     * {@snippet :
+     * JavadocSample js = new JavadocSample();}
+     */
+    private class JavadocSample {
+    }
+
+}

src/test/resources/encoding/fileUTF8.txt

@@ -0,0 +1 @@
+Zażółć gęślą jaźń

src/test/resources/encoding/fileWin1250.txt

@@ -0,0 +1 @@
+Za��� g�l� ja��