Better Pattern for First Fragment

Author: jeffgbutler

src/main/java/org/mybatis/dynamic/sql/util/FragmentCollector.java

@@ -19,6 +19,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.stream.Collector;
 import java.util.stream.Stream;
 
@@ -42,13 +43,12 @@ public FragmentCollector merge(FragmentCollector other) {
         return this;
     }
 
-    public String firstFragment() {
-        return fragments.get(0).fragment();
+    public Optional<String> firstFragment() {
+        return fragments.stream().findFirst().map(FragmentAndParameters::fragment);
     }
 
     public Stream<String> fragments() {
-        return fragments.stream()
-                .map(FragmentAndParameters::fragment);
+        return fragments.stream().map(FragmentAndParameters::fragment);
     }
 
     public Map<String, Object> parameters() {

src/main/java/org/mybatis/dynamic/sql/where/render/WhereRenderer.java

@@ -72,7 +72,10 @@ private String calculateWhereClause(FragmentCollector collector) {
             return collector.fragments()
                     .collect(Collectors.joining(" ", "where ", "")); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
         } else {
-            return "where " + stripEnclosingParenthesesIfPresent(collector.firstFragment()); //$NON-NLS-1$
+            return collector.firstFragment()
+                    .map(this::stripEnclosingParenthesesIfPresent)
+                    .map(s -> "where " + s) //$NON-NLS-1$
+                    .orElse(""); //$NON-NLS-1$
         }
     }