Fix some unit test failure (#3337)

Author: kexianjun

dubbo-plugin/dubbo-qos/src/test/java/org/apache/dubbo/qos/textui/TKvTest.java

@@ -35,9 +35,9 @@ public void test1() {
         });
 
         String kv = tKv.rendering();
-        assertThat(kv, containsString("ABCDEFGHIJ\n"));
-        assertThat(kv, containsString("KLMNOPQRST\n"));
-        assertThat(kv, containsString("UVWXYZ\n"));
+        assertThat(kv, containsString("ABCDEFGHIJ" + System.lineSeparator()));
+        assertThat(kv, containsString("KLMNOPQRST" + System.lineSeparator()));
+        assertThat(kv, containsString("UVWXYZ" + System.lineSeparator()));
 
         tTable.addRow("OPTIONS", kv);
         String table = tTable.rendering();

dubbo-plugin/dubbo-qos/src/test/java/org/apache/dubbo/qos/textui/TLadderTest.java

@@ -31,10 +31,10 @@ public void testRendering() throws Exception {
         ladder.addItem("3");
         ladder.addItem("4");
         String result = ladder.rendering();
-        String expected = "1\n" +
-                "  `-2\n" +
-                "    `-3\n" +
-                "      `-4\n";
+        String expected = "1" + System.lineSeparator() +
+                "  `-2" + System.lineSeparator() +
+                "    `-3" + System.lineSeparator() +
+                "      `-4" + System.lineSeparator();
         assertThat(result, equalTo(expected));
         System.out.println(result);
     }

dubbo-plugin/dubbo-qos/src/test/java/org/apache/dubbo/qos/textui/TTableTest.java

@@ -28,11 +28,11 @@ public void test1() throws Exception {
         table.addRow(1, "one", "uno", "un");
         table.addRow(2, "two", "dos", "deux");
         String result = table.rendering();
-        String expected = "+-+---+---+----+\n" +
-                "|1|one|uno|un  |\n" +
-                "+-+---+---+----+\n" +
-                "|2|two|dos|deux|\n" +
-                "+-+---+---+----+\n";
+        String expected = "+-+---+---+----+" + System.lineSeparator() +
+                "|1|one|uno|un  |" + System.lineSeparator() +
+                "+-+---+---+----+" + System.lineSeparator() +
+                "|2|two|dos|deux|" + System.lineSeparator() +
+                "+-+---+---+----+" + System.lineSeparator();
         assertThat(result, equalTo(expected));
         System.out.println(result);
     }
@@ -46,9 +46,9 @@ public void test2() throws Exception {
         });
         table.addRow(1, "abcde", "ABCDE");
         String result = table.rendering();
-        String expected = "+-+----------+----------+\n" +
-                "|1|   abcde  |     ABCDE|\n" +
-                "+-+----------+----------+\n";
+        String expected = "+-+----------+----------+" + System.lineSeparator() +
+                "|1|   abcde  |     ABCDE|" + System.lineSeparator() +
+                "+-+----------+----------+" + System.lineSeparator();
         assertThat(result, equalTo(expected));
         System.out.println(result);
     }