Filter blanks in getJavaClassName

This ports the same fix added to DefaultNamingStrategy from V1.

Related to #693.

Author: dagnir

codegen/src/main/java/software/amazon/awssdk/codegen/naming/DefaultNamingStrategy.java

@@ -214,7 +214,10 @@ public String getEnumValueName(String enumValue) {
 
     @Override
     public String getJavaClassName(String shapeName) {
-        return Arrays.stream(shapeName.split("[._-]|\\W")).map(Utils::capitalize).collect(Collectors.joining());
+        return Arrays.stream(shapeName.split("[._-]|\\W"))
+                     .filter(s -> !StringUtils.isEmpty(s))
+                     .map(Utils::capitalize)
+                     .collect(Collectors.joining());
     }
 
     @Override

codegen/src/test/java/software/amazon/awssdk/codegen/naming/DefaultNamingStrategyTest.java

@@ -275,4 +275,53 @@ public void getServiceName_ThrowsException_WhenServiceIdHasWhiteSpace() {
     private void validateConversion(String input, String expectedOutput) {
         assertThat(strat.getEnumValueName(input)).isEqualTo(expectedOutput);
     }
+
+    @Test
+    public void getJavaClassName_ReturnsSanitizedName_ClassStartingWithUnderscore() {
+        NamingStrategy strategy = new DefaultNamingStrategy(null, null);
+        String javaClassName = strategy.getJavaClassName("_MyClass");
+        assertThat(javaClassName).isEqualTo("MyClass");
+    }
+
+    @Test
+    public void getJavaClassName_ReturnsSanitizedName_ClassStartingWithDoubleUnderscore() {
+        NamingStrategy strategy = new DefaultNamingStrategy(null, null);
+        String javaClassName = strategy.getJavaClassName("__MyClass");
+        assertThat(javaClassName).isEqualTo("MyClass");
+    }
+
+    @Test
+    public void getJavaClassName_ReturnsSanitizedName_ClassStartingWithDoublePeriods() {
+        NamingStrategy strategy = new DefaultNamingStrategy(null, null);
+        String javaClassName = strategy.getJavaClassName("..MyClass");
+        assertThat(javaClassName).isEqualTo("MyClass");
+    }
+
+    @Test
+    public void getJavaClassName_ReturnsSanitizedName_ClassStartingWithDoubleDashes() {
+        NamingStrategy strategy = new DefaultNamingStrategy(null, null);
+        String javaClassName = strategy.getJavaClassName("--MyClass");
+        assertThat(javaClassName).isEqualTo("MyClass");
+    }
+
+    @Test
+    public void getJavaClassName_ReturnsSanitizedName_DoubleUnderscoresInClass() {
+        NamingStrategy strategy = new DefaultNamingStrategy(null, null);
+        String javaClassName = strategy.getJavaClassName("My__Class");
+        assertThat(javaClassName).isEqualTo("MyClass");
+    }
+
+    @Test
+    public void getJavaClassName_ReturnsSanitizedName_DoublePeriodsInClass() {
+        NamingStrategy strategy = new DefaultNamingStrategy(null, null);
+        String javaClassName = strategy.getJavaClassName("My..Class");
+        assertThat(javaClassName).isEqualTo("MyClass");
+    }
+
+    @Test
+    public void getJavaClassName_ReturnsSanitizedName_DoubleDashesInClass() {
+        NamingStrategy strategy = new DefaultNamingStrategy(null, null);
+        String javaClassName = strategy.getJavaClassName("My--Class");
+        assertThat(javaClassName).isEqualTo("MyClass");
+    }
 }