Write a utility method for use in a rendering pipeline

Author: jeffgbutler

src/main/java/org/mybatis/dynamic/sql/insert/render/BatchInsertRenderer.java

@@ -23,17 +23,16 @@
 public class BatchInsertRenderer<T> {
 
     private final BatchInsertModel<T> model;
-    private final RenderingStrategy renderingStrategy;
+    private final MultiRowValuePhraseVisitor visitor;
 
     private BatchInsertRenderer(Builder<T> builder) {
         model = Objects.requireNonNull(builder.model);
-        renderingStrategy = Objects.requireNonNull(builder.renderingStrategy);
+        visitor = new MultiRowValuePhraseVisitor(builder.renderingStrategy, "row"); //$NON-NLS-1$)
     }
 
     public BatchInsert<T> render() {
-        MultiRowValuePhraseVisitor visitor = new MultiRowValuePhraseVisitor(renderingStrategy, "row"); //$NON-NLS-1$)
         FieldAndValueCollector collector = model.columnMappings()
-                .map(m -> m.accept(visitor))
+                .map(visitor::renderMapping)
                 .collect(FieldAndValueCollector.collect());
 
         String insertStatement = InsertRenderingUtilities.calculateInsertStatement(model.table(), collector);

src/main/java/org/mybatis/dynamic/sql/insert/render/GeneralInsertRenderer.java

@@ -27,19 +27,19 @@
 public class GeneralInsertRenderer {
 
     private final GeneralInsertModel model;
-    private final RenderingContext renderingContext;
+    private final GeneralInsertValuePhraseVisitor visitor;
 
     private GeneralInsertRenderer(Builder builder) {
         model = Objects.requireNonNull(builder.model);
-        renderingContext = RenderingContext.withRenderingStrategy(builder.renderingStrategy)
+        RenderingContext renderingContext = RenderingContext.withRenderingStrategy(builder.renderingStrategy)
                 .withStatementConfiguration(builder.statementConfiguration)
                 .build();
+        visitor = new GeneralInsertValuePhraseVisitor(renderingContext);
     }
 
     public GeneralInsertStatementProvider render() {
-        GeneralInsertValuePhraseVisitor visitor = new GeneralInsertValuePhraseVisitor(renderingContext);
         FieldAndValueCollector collector = model.columnMappings()
-                .map(m -> m.accept(visitor))
+                .map(visitor::renderMapping)
                 .filter(Optional::isPresent)
                 .map(Optional::get)
                 .collect(FieldAndValueCollector.collect());

src/main/java/org/mybatis/dynamic/sql/insert/render/InsertRenderer.java

@@ -25,18 +25,16 @@
 public class InsertRenderer<T> {
 
     private final InsertModel<T> model;
-    private final RenderingStrategy renderingStrategy;
+    private final ValuePhraseVisitor visitor;
 
     private InsertRenderer(Builder<T> builder) {
         model = Objects.requireNonNull(builder.model);
-        renderingStrategy = Objects.requireNonNull(builder.renderingStrategy);
+        visitor = new ValuePhraseVisitor(builder.renderingStrategy);
     }
 
     public InsertStatementProvider<T> render() {
-        ValuePhraseVisitor visitor = new ValuePhraseVisitor(renderingStrategy);
-
         FieldAndValueCollector collector = model.columnMappings()
-                .map(m -> m.accept(visitor))
+                .map(visitor::renderMapping)
                 .filter(Optional::isPresent)
                 .map(Optional::get)
                 .collect(FieldAndValueCollector.collect());

src/main/java/org/mybatis/dynamic/sql/insert/render/MultiRowInsertRenderer.java

@@ -25,19 +25,17 @@
 public class MultiRowInsertRenderer<T> {
 
     private final MultiRowInsertModel<T> model;
-    private final RenderingStrategy renderingStrategy;
+    private final MultiRowValuePhraseVisitor visitor;
 
     private MultiRowInsertRenderer(Builder<T> builder) {
         model = Objects.requireNonNull(builder.model);
-        renderingStrategy = Objects.requireNonNull(builder.renderingStrategy);
+        // the prefix is a generic format that will be resolved below with String.format(...)
+        visitor = new MultiRowValuePhraseVisitor(builder.renderingStrategy, "records[%s]"); //$NON-NLS-1$
     }
 
     public MultiRowInsertStatementProvider<T> render() {
-        // the prefix is a generic format that will be resolved below with String.format(...)
-        MultiRowValuePhraseVisitor visitor =
-                new MultiRowValuePhraseVisitor(renderingStrategy, "records[%s]"); //$NON-NLS-1$
         FieldAndValueCollector collector = model.columnMappings()
-                .map(m -> m.accept(visitor))
+                .map(visitor::renderMapping)
                 .collect(FieldAndValueCollector.collect());
 
         String insertStatement = calculateInsertStatement(collector);

src/main/java/org/mybatis/dynamic/sql/insert/render/MultiRowValuePhraseVisitor.java

@@ -25,13 +25,15 @@
 import org.mybatis.dynamic.sql.util.StringConstantMapping;
 import org.mybatis.dynamic.sql.util.StringUtilities;
 
+import java.util.Objects;
+
 public class MultiRowValuePhraseVisitor extends MultiRowInsertMappingVisitor<FieldAndValueAndParameters> {
     protected final RenderingStrategy renderingStrategy;
     protected final String prefix;
 
     protected MultiRowValuePhraseVisitor(RenderingStrategy renderingStrategy, String prefix) {
-        this.renderingStrategy = renderingStrategy;
-        this.prefix = prefix;
+        this.renderingStrategy = Objects.requireNonNull(renderingStrategy);
+        this.prefix = Objects.requireNonNull(prefix);
     }
 
     @Override

src/main/java/org/mybatis/dynamic/sql/update/render/UpdateRenderer.java

@@ -37,6 +37,7 @@
 public class UpdateRenderer {
     private final UpdateModel updateModel;
     private final RenderingContext renderingContext;
+    private final SetPhraseVisitor visitor;
 
     private UpdateRenderer(Builder builder) {
         updateModel = Objects.requireNonNull(builder.updateModel);
@@ -48,6 +49,7 @@ private UpdateRenderer(Builder builder) {
                 .withTableAliasCalculator(tableAliasCalculator)
                 .withStatementConfiguration(builder.statementConfiguration)
                 .build();
+        visitor = new SetPhraseVisitor(renderingContext);
     }
 
     public UpdateStatementProvider render() {
@@ -75,10 +77,8 @@ private FragmentAndParameters calculateUpdateStatementStart() {
     }
 
     private FragmentAndParameters calculateSetPhrase() {
-        SetPhraseVisitor visitor = new SetPhraseVisitor(renderingContext);
-
         List<Optional<FragmentAndParameters>> fragmentsAndParameters = updateModel.columnMappings()
-                        .map(m -> m.accept(visitor))
+                        .map(visitor::renderMapping)
                         .collect(Collectors.toList());
 
         Validator.assertFalse(fragmentsAndParameters.stream().noneMatch(Optional::isPresent),

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

@@ -31,6 +31,10 @@
  *            The type of object created by the visitor
  */
 public interface ColumnMappingVisitor<R> {
+    default R renderMapping(AbstractColumnMapping mapping) {
+        return mapping.accept(this);
+    }
+
     R visit(NullMapping mapping);
 
     R visit(ConstantMapping mapping);