Large Refactoring

- Remove the difficult to understand build delegates in QueryDSL and
SelectDSL
- Better use of Optionals
- Allow any build method, on any intermediate object, to produce correct
results

Author: jeffgbutler

src/main/java/org/mybatis/dynamic/sql/delete/DeleteDSL.java

@@ -30,23 +30,27 @@ public class DeleteDSL<R> implements Buildable<R> {
 
     private Function<DeleteModel, R> adapterFunction;
     private SqlTable table;
+    protected DeleteWhereBuilder whereBuilder;
 
     private DeleteDSL(SqlTable table, Function<DeleteModel, R> adapterFunction) {
         this.table = Objects.requireNonNull(table);
         this.adapterFunction = Objects.requireNonNull(adapterFunction);
     }
 
     public DeleteWhereBuilder where() {
-        return new DeleteWhereBuilder();
+        whereBuilder = new DeleteWhereBuilder();
+        return whereBuilder;
     }
 
     public <T> DeleteWhereBuilder where(BindableColumn<T> column, VisitableCondition<T> condition) {
-        return new DeleteWhereBuilder(column, condition);
+        whereBuilder = new DeleteWhereBuilder(column, condition);
+        return whereBuilder;
     }
 
     public <T> DeleteWhereBuilder where(BindableColumn<T> column, VisitableCondition<T> condition,
             SqlCriterion<?>...subCriteria) {
-        return new DeleteWhereBuilder(column, condition, subCriteria);
+        whereBuilder = new DeleteWhereBuilder(column, condition, subCriteria);
+        return whereBuilder;
     }
 
     /**
@@ -57,7 +61,9 @@ public <T> DeleteWhereBuilder where(BindableColumn<T> column, VisitableCondition
      */
     @Override
     public R build() {
-        DeleteModel deleteModel = DeleteModel.withTable(table).build();
+        DeleteModel deleteModel = DeleteModel.withTable(table)
+                .withWhereModel(whereBuilder == null ? null : whereBuilder.buildWhereModel())
+                .build();
         return adapterFunction.apply(deleteModel);
     }
 
@@ -76,7 +82,7 @@ public static <T> DeleteDSL<MyBatis3DeleteModelAdapter<T>> deleteFromWithMapper(
 
     public class DeleteWhereBuilder extends AbstractWhereDSL<DeleteWhereBuilder> implements Buildable<R> {
 
-        private <T> DeleteWhereBuilder() {
+        private DeleteWhereBuilder() {
             super();
         }
 
@@ -91,10 +97,7 @@ private <T> DeleteWhereBuilder(BindableColumn<T> column, VisitableCondition<T> c
 
         @Override
         public R build() {
-            DeleteModel deleteModel = DeleteModel.withTable(table)
-                    .withWhereModel(buildWhereModel())
-                    .build();
-            return adapterFunction.apply(deleteModel);
+            return DeleteDSL.this.build();
         }
 
         @Override

src/main/java/org/mybatis/dynamic/sql/delete/DeleteModel.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2018 the original author or authors.
+ *    Copyright 2016-2019 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.

src/main/java/org/mybatis/dynamic/sql/delete/render/DeleteRenderer.java

@@ -17,8 +17,6 @@
 
 import static org.mybatis.dynamic.sql.util.StringUtilities.spaceBefore;
 
-import java.util.Collections;
-import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -40,13 +38,33 @@ private DeleteRenderer(Builder builder) {
     }
 
     public DeleteStatementProvider render() {
-        Optional<WhereClauseProvider> whereClause = deleteModel.whereModel().flatMap(this::renderWhereClause);
-        
-        return DefaultDeleteStatementProvider.withDeleteStatement(calculateDeleteStatement(whereClause))
-                .withParameters(calculateParameters(whereClause))
+        return deleteModel.whereModel()
+                .flatMap(this::renderWhereClause)
+                .map(this::renderWithWhereClause)
+                .orElseGet(this::renderWithoutWhereClause);
+    }
+    
+    private DeleteStatementProvider renderWithWhereClause(WhereClauseProvider whereClauseProvider) {
+        return DefaultDeleteStatementProvider.withDeleteStatement(calculateDeleteStatement(whereClauseProvider))
+                .withParameters(whereClauseProvider.getParameters())
                 .build();
     }
+    
+    private String calculateDeleteStatement(WhereClauseProvider whereClause) {
+        return calculateDeleteStatement()
+                + spaceBefore(whereClause.getWhereClause());
+    }
 
+    private String calculateDeleteStatement() {
+        return "delete from" //$NON-NLS-1$
+                + spaceBefore(deleteModel.table().tableNameAtRuntime());
+    }
+    
+    private DeleteStatementProvider renderWithoutWhereClause() {
+        return DefaultDeleteStatementProvider.withDeleteStatement(calculateDeleteStatement())
+                .build();
+    }
+    
     private Optional<WhereClauseProvider> renderWhereClause(WhereModel whereModel) {
         return WhereRenderer.withWhereModel(whereModel)
                 .withRenderingStrategy(renderingStrategy)
@@ -56,18 +74,6 @@ private Optional<WhereClauseProvider> renderWhereClause(WhereModel whereModel) {
                 .render();
     }
 
-    private String calculateDeleteStatement(Optional<WhereClauseProvider> whereClause) {
-        return "delete from" //$NON-NLS-1$
-                + spaceBefore(deleteModel.table().tableNameAtRuntime())
-                + spaceBefore(whereClause.map(WhereClauseProvider::getWhereClause));
-    }
-    
-    private Map<String, Object> calculateParameters(Optional<WhereClauseProvider> whereClause) {
-        return whereClause
-                .map(WhereClauseProvider::getParameters)
-                .orElse(Collections.emptyMap());
-    }
-
     public static Builder withDeleteModel(DeleteModel deleteModel) {
         return new Builder().withDeleteModel(deleteModel);
     }

src/main/java/org/mybatis/dynamic/sql/render/MyBatis3RenderingStrategy.java

@@ -15,13 +15,20 @@
  */
 package org.mybatis.dynamic.sql.render;
 
-import java.util.Optional;
-
 import org.mybatis.dynamic.sql.BindableColumn;
 
 public class MyBatis3RenderingStrategy extends RenderingStrategy {
     @Override
-    public String getFormattedJdbcPlaceholder(Optional<BindableColumn<?>> column, String prefix, String parameterName) {
+    public String getFormattedJdbcPlaceholder(String prefix, String parameterName) {
+        return "#{" //$NON-NLS-1$
+                + prefix
+                + "." //$NON-NLS-1$
+                + parameterName
+                + "}"; //$NON-NLS-1$
+    }
+
+    @Override
+    public String getFormattedJdbcPlaceholder(BindableColumn<?> column, String prefix, String parameterName) {
         return "#{" //$NON-NLS-1$
                 + prefix
                 + "." //$NON-NLS-1$
@@ -31,16 +38,14 @@ public String getFormattedJdbcPlaceholder(Optional<BindableColumn<?>> column, St
                 + "}"; //$NON-NLS-1$
     }
 
-    private String renderTypeHandler(Optional<BindableColumn<?>> column) {
-        return column
-                .flatMap(BindableColumn::typeHandler)
+    private String renderTypeHandler(BindableColumn<?> column) {
+        return column.typeHandler()
                 .map(th -> ",typeHandler=" + th) //$NON-NLS-1$
                 .orElse(""); //$NON-NLS-1$
     }
 
-    private String renderJdbcType(Optional<BindableColumn<?>> column) {
-        return column
-                .flatMap(BindableColumn::jdbcType)
+    private String renderJdbcType(BindableColumn<?> column) {
+        return column.jdbcType()
                 .map(jt -> ",jdbcType=" + jt.getName()) //$NON-NLS-1$
                 .orElse(""); //$NON-NLS-1$
     }

src/main/java/org/mybatis/dynamic/sql/render/RenderingStrategy.java

@@ -15,8 +15,6 @@
  */
 package org.mybatis.dynamic.sql.render;
 
-import java.util.Optional;
-
 import org.mybatis.dynamic.sql.BindableColumn;
 
 public abstract class RenderingStrategy {
@@ -26,14 +24,7 @@ public abstract class RenderingStrategy {
     public static final RenderingStrategy SPRING_NAMED_PARAMETER = new SpringNamedParameterRenderingStrategy();
     public static final String DEFAULT_PARAMETER_PREFIX = "parameters"; //$NON-NLS-1$
 
-    public String getFormattedJdbcPlaceholder(BindableColumn<?> column, String prefix, String parameterName) {
-        return getFormattedJdbcPlaceholder(Optional.of(column), prefix, parameterName);
-    }
-
-    public String getFormattedJdbcPlaceholder(String prefix, String parameterName) {
-        return getFormattedJdbcPlaceholder(Optional.empty(), prefix, parameterName);
-    }
+    public abstract String getFormattedJdbcPlaceholder(BindableColumn<?> column, String prefix, String parameterName);
 
-    public abstract String getFormattedJdbcPlaceholder(Optional<BindableColumn<?>> column, String prefix,
-            String parameterName);
+    public abstract String getFormattedJdbcPlaceholder(String prefix, String parameterName);
 }

src/main/java/org/mybatis/dynamic/sql/render/SpringNamedParameterRenderingStrategy.java

@@ -15,14 +15,17 @@
  */
 package org.mybatis.dynamic.sql.render;
 
-import java.util.Optional;
-
 import org.mybatis.dynamic.sql.BindableColumn;
 
 public class SpringNamedParameterRenderingStrategy extends RenderingStrategy {
 
     @Override
-    public String getFormattedJdbcPlaceholder(Optional<BindableColumn<?>> column, String prefix, String parameterName) {
+    public String getFormattedJdbcPlaceholder(BindableColumn<?> column, String prefix, String parameterName) {
+        return getFormattedJdbcPlaceholder(prefix, parameterName);
+    }
+
+    @Override
+    public String getFormattedJdbcPlaceholder(String prefix, String parameterName) {
         return ":" + parameterName; //$NON-NLS-1$
     }
 }