Add FreeMarkerLanguageDriverConfig

pom.xml

@@ -90,6 +90,11 @@
       <artifactId>freemarker</artifactId>
       <version>2.3.28</version>
     </dependency>
+    <dependency>
+      <groupId>org.apache.commons</groupId>
+      <artifactId>commons-text</artifactId>
+      <version>1.6</version>
+    </dependency>
 
     <!-- TEST -->
     <dependency>

src/main/java/org/mybatis/scripting/freemarker/FreeMarkerLanguageDriver.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2015-2018 the original author or authors.
+ *    Copyright 2015-2019 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.
@@ -20,10 +20,7 @@
 import freemarker.template.Template;
 
 import java.io.IOException;
-import java.io.InputStream;
 import java.io.StringReader;
-import java.nio.charset.StandardCharsets;
-import java.util.Properties;
 
 import org.apache.ibatis.executor.parameter.ParameterHandler;
 import org.apache.ibatis.mapping.BoundSql;
@@ -39,36 +36,32 @@
  * configuration, use can inherit from this class and override {@link #createFreeMarkerConfiguration()} method.
  *
  * @author elwood
+ * @author Kazuki Shimizu
  */
 public class FreeMarkerLanguageDriver implements LanguageDriver {
+
+  protected final FreeMarkerLanguageDriverConfig driverConfig;
+  protected final freemarker.template.Configuration freemarkerCfg;
+
   /**
-   * Base package for all FreeMarker templates.
+   * Constructor.
+   *
+   * @see FreeMarkerLanguageDriverConfig#newInstance()
    */
-  public static final String basePackage;
-
-  public static final String DEFAULT_BASE_PACKAGE = "";
-
-  static {
-    Properties properties = new Properties();
-    try {
-      try (InputStream stream = FreeMarkerLanguageDriver.class.getClassLoader()
-          .getResourceAsStream("mybatis-freemarker.properties")) {
-        if (stream != null) {
-          properties.load(stream);
-          basePackage = properties.getProperty("basePackage", DEFAULT_BASE_PACKAGE);
-        } else {
-          basePackage = DEFAULT_BASE_PACKAGE;
-        }
-      }
-    } catch (IOException e) {
-      throw new IllegalStateException(e);
-    }
+  public FreeMarkerLanguageDriver() {
+    this(FreeMarkerLanguageDriverConfig.newInstance());
   }
 
-  protected freemarker.template.Configuration freemarkerCfg;
-
-  public FreeMarkerLanguageDriver() {
-    freemarkerCfg = createFreeMarkerConfiguration();
+  /**
+   * Constructor.
+   *
+   * @param driverConfig
+   *          a language driver configuration
+   * @since 1.2.0
+   */
+  public FreeMarkerLanguageDriver(FreeMarkerLanguageDriverConfig driverConfig) {
+    this.driverConfig = driverConfig;
+    this.freemarkerCfg = createFreeMarkerConfiguration();
   }
 
   /**
@@ -77,16 +70,17 @@ public FreeMarkerLanguageDriver() {
    */
   protected freemarker.template.Configuration createFreeMarkerConfiguration() {
     freemarker.template.Configuration cfg = new freemarker.template.Configuration(
-        freemarker.template.Configuration.VERSION_2_3_22);
+        driverConfig.getIncompatibleImprovementsVersion());
 
-    TemplateLoader templateLoader = new ClassTemplateLoader(this.getClass().getClassLoader(), basePackage);
+    TemplateLoader templateLoader = new ClassTemplateLoader(this.getClass().getClassLoader(),
+        driverConfig.getBasePackage());
     cfg.setTemplateLoader(templateLoader);
 
     // To avoid formatting numbers using spaces and commas in SQL
     cfg.setNumberFormat("computer");
 
     // Because it defaults to default system encoding, we should set it always explicitly
-    cfg.setDefaultEncoding(StandardCharsets.UTF_8.name());
+    cfg.setDefaultEncoding(driverConfig.getDefaultEncoding().name());
 
     return cfg;
   }

src/main/java/org/mybatis/scripting/freemarker/FreeMarkerLanguageDriverConfig.java

@@ -0,0 +1,252 @@
+/**
+ *    Copyright 2015-2019 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.
+ */
+package org.mybatis.scripting.freemarker;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.Properties;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+import freemarker.template.Configuration;
+import freemarker.template.Version;
+import org.apache.commons.text.WordUtils;
+import org.apache.ibatis.io.Resources;
+import org.apache.ibatis.reflection.DefaultReflectorFactory;
+import org.apache.ibatis.reflection.MetaObject;
+import org.apache.ibatis.reflection.factory.DefaultObjectFactory;
+import org.apache.ibatis.reflection.wrapper.DefaultObjectWrapperFactory;
+
+/**
+ * Configuration class for {@link FreeMarkerLanguageDriver}.
+ *
+ * @author Kazuki Shimizu
+ * @since 1.2.0
+ */
+public class FreeMarkerLanguageDriverConfig {
+
+  private static final String PROPERTY_KEY_CONFIG_FILE = "mybatis-freemarker.config.file";
+  private static final String PROPERTY_KEY_CONFIG_ENCODING = "mybatis-freemarker.config.encoding";
+  private static final String DEFAULT_PROPERTIES_FILE = "mybatis-freemarker.properties";
+  private static Map<Class<?>, Function<String, Object>> TYPE_CONVERTERS;
+
+  static {
+    Map<Class<?>, Function<String, Object>> converters = new HashMap<>();
+    converters.put(String.class, String::trim);
+    converters.put(Version.class, v -> new Version(v.trim()));
+    converters.put(Charset.class, v -> Charset.forName(v.trim()));
+    TYPE_CONVERTERS = Collections.unmodifiableMap(converters);
+  }
+
+  /**
+   * The base directory for reading template resources.
+   */
+  private String basePackage = "";
+
+  /**
+   * The default encoding for reading template resources.
+   */
+  private Charset defaultEncoding = StandardCharsets.UTF_8;
+
+  /**
+   * The incompatible improvements version of freemarker.
+   */
+  private Version incompatibleImprovementsVersion = Configuration.VERSION_2_3_22;
+
+  /**
+   * Get a base directory for reading template resources.
+   * <p>
+   * Default is none (just under classpath).
+   * </p>
+   *
+   * @return a base directory for reading template resources
+   */
+  public String getBasePackage() {
+    return basePackage;
+  }
+
+  /**
+   * Set a base directory for reading template resources.
+   *
+   * @param basePackage
+   *          a base directory for reading template resources
+   */
+  public void setBasePackage(String basePackage) {
+    this.basePackage = basePackage;
+  }
+
+  /**
+   * Get a default encoding for reading template resources.
+   * <p>
+   * Default is {@code UTF-8}.
+   * </p>
+   *
+   * @return a default encoding for reading template resources
+   */
+  public Charset getDefaultEncoding() {
+    return defaultEncoding;
+  }
+
+  /**
+   * Set a default encoding for reading template resources.
+   *
+   * @param defaultEncoding
+   *          a default encoding for reading template resources
+   */
+  public void setDefaultEncoding(Charset defaultEncoding) {
+    this.defaultEncoding = defaultEncoding;
+  }
+
+  /**
+   * Get an incompatible improvements version of freemarker.
+   * <p>
+   * Default is 2.3.22.
+   * </p>
+   * 
+   * @return an incompatible improvements version of freemarker
+   */
+  public Version getIncompatibleImprovementsVersion() {
+    return incompatibleImprovementsVersion;
+  }
+
+  /**
+   * Set an incompatible improvements version of freemarker.
+   *
+   * @param incompatibleImprovementsVersion
+   *          an incompatible improvements version of freemarker
+   */
+  public void setIncompatibleImprovementsVersion(Version incompatibleImprovementsVersion) {
+    this.incompatibleImprovementsVersion = incompatibleImprovementsVersion;
+  }
+
+  /**
+   * Create an instance from default properties file. <br>
+   * If you want to customize a default {@code TemplateEngine}, you can configure some property using
+   * mybatis-freemarker.properties that encoded by UTF-8. Also, you can change the properties file that will read using
+   * system property (-Dmybatis-freemarker.config.file=... -Dmybatis-freemarker.config.encoding=...). <br>
+   * Supported properties are as follows:
+   * <table border="1">
+   * <caption>Supported properties</caption>
+   * <tr>
+   * <th>Property Key</th>
+   * <th>Description</th>
+   * <th>Default</th>
+   * </tr>
+   * <tr>
+   * <th colspan="3">General configuration</th>
+   * </tr>
+   * <tr>
+   * <td>base-package</td>
+   * <td>The base directory for reading template resources</td>
+   * <td>None(just under classpath)</td>
+   * </tr>
+   * <tr>
+   * <td>default-encoding</td>
+   * <td>The default encoding for reading template resources</td>
+   * <td>UTF-8</td>
+   * </tr>
+   * <tr>
+   * <td>freemarker-incompatible-improvements-version</td>
+   * <td>The incompatible improvements version of freemarker</td>
+   * <td>2.3.22</td>
+   * </tr>
+   * </table>
+   *
+   * @return a configuration instance
+   */
+  public static FreeMarkerLanguageDriverConfig newInstance() {
+    return newInstance(loadDefaultProperties());
+  }
+
+  /**
+   * Create an instance from specified properties.
+   *
+   * @param customProperties
+   *          custom configuration properties
+   * @return a configuration instance
+   * @see #newInstance()
+   */
+  public static FreeMarkerLanguageDriverConfig newInstance(Properties customProperties) {
+    FreeMarkerLanguageDriverConfig config = new FreeMarkerLanguageDriverConfig();
+    Properties properties = loadDefaultProperties();
+    Optional.ofNullable(customProperties).ifPresent(properties::putAll);
+    override(config, properties);
+    return config;
+  }
+
+  /**
+   * Create an instance using specified customizer and override using a default properties file.
+   *
+   * @param customizer
+   *          baseline customizer
+   * @return a configuration instance
+   * @see #newInstance()
+   */
+  public static FreeMarkerLanguageDriverConfig newInstance(Consumer<FreeMarkerLanguageDriverConfig> customizer) {
+    FreeMarkerLanguageDriverConfig config = new FreeMarkerLanguageDriverConfig();
+    customizer.accept(config);
+    override(config, loadDefaultProperties());
+    return config;
+  }
+
+  private static void override(FreeMarkerLanguageDriverConfig config, Properties properties) {
+    MetaObject metaObject = MetaObject.forObject(config, new DefaultObjectFactory(), new DefaultObjectWrapperFactory(),
+        new DefaultReflectorFactory());
+    properties.forEach((key, value) -> {
+      String propertyPath = WordUtils
+          .uncapitalize(WordUtils.capitalize(Objects.toString(key), '-').replaceAll("-", ""));
+      Optional.ofNullable(value).ifPresent(v -> {
+        Object convertedValue = TYPE_CONVERTERS.get(metaObject.getSetterType(propertyPath)).apply(value.toString());
+        metaObject.setValue(propertyPath, convertedValue);
+      });
+    });
+  }
+
+  private static Properties loadDefaultProperties() {
+    return loadProperties(System.getProperty(PROPERTY_KEY_CONFIG_FILE, DEFAULT_PROPERTIES_FILE));
+  }
+
+  private static Properties loadProperties(String resourcePath) {
+    Properties properties = new Properties();
+    InputStream in;
+    try {
+      in = Resources.getResourceAsStream(resourcePath);
+    } catch (IOException e) {
+      in = null;
+    }
+    if (in != null) {
+      Charset encoding = Optional.ofNullable(System.getProperty(PROPERTY_KEY_CONFIG_ENCODING)).map(Charset::forName)
+          .orElse(StandardCharsets.UTF_8);
+      try (InputStreamReader inReader = new InputStreamReader(in, encoding);
+          BufferedReader bufReader = new BufferedReader(inReader)) {
+        properties.load(bufReader);
+      } catch (IOException e) {
+        throw new IllegalStateException(e);
+      }
+    }
+    return properties;
+  }
+
+}