Add a Kotlin DSL

pom.xml

@@ -15,14 +15,9 @@
        limitations under the License.
 
 -->
-<!-- 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. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 
-  Unless required by applicable law or agreed to in writing, software distributed 
-  under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES 
-  OR CONDITIONS OF ANY KIND, either express or implied. See the License for 
-  the specific language governing permissions and limitations under the License. -->
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <parent>
     <groupId>org.mybatis</groupId>
@@ -45,6 +40,11 @@
     <spring.batch.version>4.1.2.RELEASE</spring.batch.version>
     <clirr.comparisonVersion>1.1.0</clirr.comparisonVersion>
     <module.name>org.mybatis.dynamic.sql</module.name>
+    <kotlin.version>1.3.50</kotlin.version>
+    <kotlin.compiler.jvmTarget>1.8</kotlin.compiler.jvmTarget>
+    <sonar.sources>pom.xml,src/main/java,src/main/kotlin</sonar.sources>
+    <sonar.tests>src/test/java,src/test/kotlin</sonar.tests>
+    <jacoco.version>0.8.4</jacoco.version>
   </properties>
 
   <build>
@@ -60,6 +60,68 @@
       </plugins>
     </pluginManagement>
     <plugins>
+      <plugin>
+        <groupId>org.jetbrains.kotlin</groupId>
+        <artifactId>kotlin-maven-plugin</artifactId>
+        <version>${kotlin.version}</version>
+        <executions>
+          <execution>
+            <id>compile</id>
+            <goals>
+              <goal>compile</goal>
+            </goals>
+            <configuration>
+              <sourceDirs>
+                <sourceDir>${project.basedir}/src/main/kotlin</sourceDir>
+                <sourceDir>${project.basedir}/src/main/java</sourceDir>
+              </sourceDirs>
+            </configuration>
+          </execution>
+          <execution>
+            <id>test-compile</id>
+            <goals>
+              <goal>test-compile</goal>
+            </goals>
+            <configuration>
+              <sourceDirs>
+                <sourceDir>${project.basedir}/src/test/kotlin</sourceDir>
+                <sourceDir>${project.basedir}/src/test/java</sourceDir>
+              </sourceDirs>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <executions>
+          <!-- Replacing default-compile as it is treated specially by maven -->
+          <execution>
+            <id>default-compile</id>
+            <phase>none</phase>
+          </execution>
+          <!-- Replacing default-testCompile as it is treated specially by 
+            maven -->
+          <execution>
+            <id>default-testCompile</id>
+            <phase>none</phase>
+          </execution>
+          <execution>
+            <id>java-compile</id>
+            <phase>compile</phase>
+            <goals>
+              <goal>compile</goal>
+            </goals>
+          </execution>
+          <execution>
+            <id>java-test-compile</id>
+            <phase>test-compile</phase>
+            <goals>
+              <goal>testCompile</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
       <!-- Copy the changelog into the generated site -->
       <plugin>
         <artifactId>maven-resources-plugin</artifactId>
@@ -82,6 +144,24 @@
           </execution>
         </executions>
       </plugin>
+      <plugin>
+        <groupId>com.github.ozsie</groupId>
+        <artifactId>detekt-maven-plugin</artifactId>
+        <version>1.0.0</version>
+        <executions>
+          <execution>
+            <phase>verify</phase>
+            <goals><goal>check</goal></goals>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
+        <groupId>org.eluder.coveralls</groupId>
+        <artifactId>coveralls-maven-plugin</artifactId>
+        <configuration>
+          <sourceDirectories>src/main/java,src/main/kotlin</sourceDirectories>
+        </configuration>
+      </plugin>
     </plugins>
   </build>
 
@@ -98,6 +178,12 @@
   </reporting>
 
   <dependencies>
+    <dependency>
+      <groupId>org.jetbrains.kotlin</groupId>
+      <artifactId>kotlin-stdlib-jdk8</artifactId>
+      <version>${kotlin.version}</version>
+      <scope>provided</scope>
+    </dependency>
     <dependency>
       <groupId>org.junit.jupiter</groupId>
       <artifactId>junit-jupiter-api</artifactId>

src/main/java/org/mybatis/dynamic/sql/SqlBuilder.java

@@ -25,6 +25,7 @@
 import org.mybatis.dynamic.sql.insert.InsertDSL;
 import org.mybatis.dynamic.sql.insert.InsertSelectDSL;
 import org.mybatis.dynamic.sql.insert.MultiRowInsertDSL;
+import org.mybatis.dynamic.sql.select.CountDSL;
 import org.mybatis.dynamic.sql.select.QueryExpressionDSL.FromGatherer;
 import org.mybatis.dynamic.sql.select.SelectDSL;
 import org.mybatis.dynamic.sql.select.SelectModel;
@@ -43,10 +44,9 @@
 import org.mybatis.dynamic.sql.select.function.Substring;
 import org.mybatis.dynamic.sql.select.function.Subtract;
 import org.mybatis.dynamic.sql.select.function.Upper;
-import org.mybatis.dynamic.sql.select.join.AndJoinCriterion;
 import org.mybatis.dynamic.sql.select.join.EqualTo;
 import org.mybatis.dynamic.sql.select.join.JoinCondition;
-import org.mybatis.dynamic.sql.select.join.OnJoinCriterion;
+import org.mybatis.dynamic.sql.select.join.JoinCriterion;
 import org.mybatis.dynamic.sql.update.UpdateDSL;
 import org.mybatis.dynamic.sql.update.UpdateModel;
 import org.mybatis.dynamic.sql.util.Buildable;
@@ -103,6 +103,10 @@
 public interface SqlBuilder {
 
     // statements
+    static CountDSL<SelectModel> countFrom(SqlTable table) {
+        return CountDSL.countFrom(table);
+    }
+
     static DeleteDSL<DeleteModel> deleteFrom(SqlTable table) {
         return DeleteDSL.deleteFrom(table);
     }
@@ -192,15 +196,17 @@ static <T> SqlCriterion<T> and(BindableColumn<T> column, VisitableCondition<T> c
     }
 
     // join support
-    static AndJoinCriterion and(BasicColumn joinColumn, JoinCondition joinCondition) {
-        return new AndJoinCriterion.Builder()
+    static JoinCriterion and(BasicColumn joinColumn, JoinCondition joinCondition) {
+        return new JoinCriterion.Builder()
+                .withConnector("and") //$NON-NLS-1$
                 .withJoinColumn(joinColumn)
                 .withJoinCondition(joinCondition)
                 .build();
     }
 
-    static OnJoinCriterion on(BasicColumn joinColumn, JoinCondition joinCondition) {
-        return new OnJoinCriterion.Builder()
+    static JoinCriterion on(BasicColumn joinColumn, JoinCondition joinCondition) {
+        return new JoinCriterion.Builder()
+                .withConnector("on") //$NON-NLS-1$
                 .withJoinColumn(joinColumn)
                 .withJoinCondition(joinCondition)
                 .build();
@@ -547,7 +553,16 @@ static <T> IsNotLikeWhenPresent<T> isNotLikeWhenPresent(T value) {
     static <T> IsNotLikeWhenPresent<T> isNotLikeWhenPresent(Supplier<T> valueSupplier) {
         return IsNotLikeWhenPresent.of(valueSupplier);
     }
-
+
+    // shortcuts for booleans
+    static IsEqualTo<Boolean> isTrue() {
+        return isEqualTo(Boolean.TRUE);
+    }
+
+    static IsEqualTo<Boolean> isFalse() {
+        return isEqualTo(Boolean.FALSE);
+    }
+
     // conditions for strings only
     static IsLikeCaseInsensitive isLikeCaseInsensitive(String value) {
         return isLikeCaseInsensitive(() -> value);

src/main/java/org/mybatis/dynamic/sql/SqlTable.java

@@ -19,6 +19,7 @@
 import java.util.Objects;
 import java.util.Optional;
 import java.util.function.Supplier;
+import org.jetbrains.annotations.NotNull;
 
 public class SqlTable {
 
@@ -84,15 +85,18 @@ public String tableNameAtRuntime() {
     public <T> SqlColumn<T> allColumns() {
         return SqlColumn.of("*", this); //$NON-NLS-1$
     }
-
+
+    @NotNull
     public <T> SqlColumn<T> column(String name) {
         return SqlColumn.of(name, this);
     }
 
+    @NotNull
     public <T> SqlColumn<T> column(String name, JDBCType jdbcType) {
         return SqlColumn.of(name, this, jdbcType);
     }
 
+    @NotNull
     public <T> SqlColumn<T> column(String name, JDBCType jdbcType, String typeHandler) {
         return SqlColumn.of(name, this, jdbcType).withTypeHandler(typeHandler);
     }

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

@@ -32,29 +32,23 @@ public class DeleteDSL<R> implements Buildable<R> {
 
     private Function<DeleteModel, R> adapterFunction;
     private SqlTable table;
-    protected DeleteWhereBuilder whereBuilder;
+    private DeleteWhereBuilder whereBuilder = new DeleteWhereBuilder();
 
     private DeleteDSL(SqlTable table, Function<DeleteModel, R> adapterFunction) {
         this.table = Objects.requireNonNull(table);
         this.adapterFunction = Objects.requireNonNull(adapterFunction);
     }
 
     public DeleteWhereBuilder where() {
-        whereBuilder = new DeleteWhereBuilder();
-        return whereBuilder;
-    }
-
-    public <T> DeleteWhereBuilder where(BindableColumn<T> column, VisitableCondition<T> condition) {
-        whereBuilder = new DeleteWhereBuilder(column, condition);
         return whereBuilder;
     }
 
     public <T> DeleteWhereBuilder where(BindableColumn<T> column, VisitableCondition<T> condition,
             SqlCriterion<?>...subCriteria) {
-        whereBuilder = new DeleteWhereBuilder(column, condition, subCriteria);
+        whereBuilder.and(column, condition, subCriteria);
         return whereBuilder;
     }
-    
+
     /**
      * WARNING! Calling this method could result in an delete statement that deletes
      * all rows in a table.
@@ -64,7 +58,7 @@ public <T> DeleteWhereBuilder where(BindableColumn<T> column, VisitableCondition
     @Override
     public R build() {
         DeleteModel deleteModel = DeleteModel.withTable(table)
-                .withWhereModel(whereBuilder == null ? null : whereBuilder.buildWhereModel())
+                .withWhereModel(whereBuilder.buildWhereModel())
                 .build();
         return adapterFunction.apply(deleteModel);
     }
@@ -99,15 +93,6 @@ private DeleteWhereBuilder() {
             super();
         }
 
-        private <T> DeleteWhereBuilder(BindableColumn<T> column, VisitableCondition<T> condition) {
-            super(column, condition);
-        }
-
-        private <T> DeleteWhereBuilder(BindableColumn<T> column, VisitableCondition<T> condition,
-                SqlCriterion<?>...subCriteria) {
-            super(column, condition, subCriteria);
-        }
-
         @Override
         public R build() {
             return DeleteDSL.this.build();

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

@@ -23,9 +23,9 @@
 import org.mybatis.dynamic.sql.util.mybatis3.MyBatis3Utils;
 
 /**
- * Represents a function that can be used to create a general delete method in the style
- * of MyBatis Generator. When using this function, you can create a method that does not require a user to
- * call the build() and render() methods - making client code look a bit cleaner.
+ * Represents a function that can be used to create a simplified delete method. When using this function
+ * you can create a method that does not require a user to call the build() and render() methods - making
+ *  client code look a bit cleaner.
  * 
  * <p>This function is intended to be used in conjunction with a utility method like
  *  {@link MyBatis3Utils#deleteFrom(ToIntFunction, SqlTable, DeleteDSLCompleter)}

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

@@ -18,6 +18,7 @@
 import java.util.Objects;
 import java.util.Optional;
 
+import org.jetbrains.annotations.NotNull;
 import org.mybatis.dynamic.sql.SqlTable;
 import org.mybatis.dynamic.sql.delete.render.DeleteRenderer;
 import org.mybatis.dynamic.sql.delete.render.DeleteStatementProvider;
@@ -40,7 +41,8 @@ public SqlTable table() {
     public Optional<WhereModel> whereModel() {
         return Optional.ofNullable(whereModel);
     }
-
+
+    @NotNull
     public DeleteStatementProvider render(RenderingStrategy renderingStrategy) {
         return DeleteRenderer.withDeleteModel(this)
                 .withRenderingStrategy(renderingStrategy)