Added a testJapan function in Java tests

This will write a string with wide characters
("state of Japan" copied to Wikipedia), ensuring this is loaded
correctly.

Also added a testCharArray() that mimics the writing of
what is excepted by test_char_array().

Author: tcalmant

tests/java/src/test/java/OneTest.java

@@ -196,6 +196,25 @@ public void testChars() throws IOException {
 		oos.close();
 	}
 
+	@Test
+	public void testCharArray() throws IOException {
+		char[] array = new char[] {
+			'\u0000', '\ud800',
+			'\u0001', '\udc00',
+			'\u0002', '\uffff',
+			'\u0003'
+		};
+		oos.writeObject(array);
+		oos.close();
+	}
+
+	@Test
+	public void testJapan() throws IOException {
+		String stateOfJapan = "日本国";
+		oos.writeObject(stateOfJapan);
+		oos.close();
+	}
+
 	@Test
 	public void testClass() throws Exception {
 		oos.writeObject(String.class);