[CLI-321] Add and use a Converter interface and implementations without using BeanUtils

pom.xml

@@ -192,6 +192,11 @@
       <artifactId>junit-vintage-engine</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-params</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <properties>
@@ -246,6 +251,7 @@
         <configuration>
           <excludeFilterFile>${basedir}/src/conf/spotbugs-exclude-filter.xml</excludeFilterFile>
         </configuration>
+        <version>4.8.2.0</version>
       </plugin>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>

src/main/java/org/apache/commons/cli/CommandLine.java

@@ -25,6 +25,7 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Properties;
+import java.util.function.Supplier;
 
 /**
  * Represents list of arguments parsed against a {@link Options} descriptor.
@@ -254,6 +255,18 @@ public String getOptionValue(final char opt) {
      * @return Value of the argument if option is set, and has an argument, otherwise {@code defaultValue}.
      */
     public String getOptionValue(final char opt, final String defaultValue) {
+        return getOptionValue(String.valueOf(opt), () -> defaultValue);
+    }
+
+    /**
+     * Gets the argument, if any, of an option.
+     *
+     * @param opt character name of the option
+     * @param defaultValue is a supplier for the default value to be returned if the option is not specified.
+     * @return Value of the argument if option is set, and has an argument, otherwise {@code defaultValue}.
+     * @since 1.7.0
+     */
+    public String getOptionValue(final char opt, final Supplier<String> defaultValue) {
         return getOptionValue(String.valueOf(opt), defaultValue);
     }
 
@@ -281,10 +294,22 @@ public String getOptionValue(final Option option) {
      * @since 1.5.0
      */
     public String getOptionValue(final Option option, final String defaultValue) {
-        final String answer = getOptionValue(option);
-        return answer != null ? answer : defaultValue;
+        return getOptionValue(option, () -> defaultValue);
     }
 
+    /**
+     * Gets the first argument, if any, of an option.
+     *
+     * @param option name of the option.
+     * @param defaultValue is a supplier for the default value to be returned if the option is not specified.
+     * @return Value of the argument if option is set, and has an argument, otherwise {@code defaultValue}.
+     * @since 1.7.0
+     */
+    public String getOptionValue(final Option option, final Supplier<String> defaultValue) {
+        final String answer = getOptionValue(option);
+        return answer != null ? answer : defaultValue.get();
+    }
+
     /**
      * Gets the first argument, if any, of this option.
      *
@@ -303,9 +328,22 @@ public String getOptionValue(final String opt) {
      * @return Value of the argument if option is set, and has an argument, otherwise {@code defaultValue}.
      */
     public String getOptionValue(final String opt, final String defaultValue) {
+        return getOptionValue(resolveOption(opt), () -> defaultValue);
+    }
+
+    /**
+     * Gets the first argument, if any, of an option.
+     *
+     * @param opt name of the option.
+     * @param defaultValue is a supplier for the default value to be returned if the option is not specified.
+     * @return Value of the argument if option is set, and has an argument, otherwise {@code defaultValue}.
+     * @since 1.7.0
+     */
+    public String getOptionValue(final String opt, final Supplier<String> defaultValue) {
         return getOptionValue(resolveOption(opt), defaultValue);
     }
 
+
     /**
      * Gets the array of values, if any, of an option.
      *
@@ -349,46 +387,97 @@ public String[] getOptionValues(final String opt) {
      * Gets a version of this {@code Option} converted to a particular type.
      *
      * @param opt the name of the option.
+     * @param <T> The return type for the method.
      * @return the value parsed into a particular object.
      * @throws ParseException if there are problems turning the option value into the desired type
      * @see PatternOptionBuilder
      * @since 1.5.0
      */
-    public Object getParsedOptionValue(final char opt) throws ParseException {
+    public <T> T getParsedOptionValue(final char opt) throws ParseException {
         return getParsedOptionValue(String.valueOf(opt));
     }
 
     /**
      * Gets a version of this {@code Option} converted to a particular type.
      *
      * @param option the name of the option.
+     * @param <T> The return type for the method.
      * @return the value parsed into a particular object.
      * @throws ParseException if there are problems turning the option value into the desired type
      * @see PatternOptionBuilder
      * @since 1.5.0
      */
-    public Object getParsedOptionValue(final Option option) throws ParseException {
+    public <T> T getParsedOptionValue(final Option option) throws ParseException {
+        return  getParsedOptionValue(option, null);
+    }
+
+    /**
+     * Gets a version of this {@code Option} converted to a particular type.
+     *
+     * @param opt the name of the option.
+     * @param <T> The return type for the method.
+     * @return the value parsed into a particular object.
+     * @throws ParseException if there are problems turning the option value into the desired type
+     * @see PatternOptionBuilder
+     * @since 1.2
+     */
+    public <T> T getParsedOptionValue(final String opt) throws ParseException {
+        return getParsedOptionValue(resolveOption(opt));
+    }
+
+    /**
+     * Gets a version of this {@code Option} converted to a particular type.
+     *
+     * @param opt the name of the option.
+     * @param defaultValue the default value to return if opt is not set.
+     * @param <T> The return type for the method.
+     * @return the value parsed into a particular object.
+     * @throws ParseException if there are problems turning the option value into the desired type
+     * @see PatternOptionBuilder
+     * @since 1.7.0
+     */
+    public <T> T getParsedOptionValue(final char opt, final T defaultValue) throws ParseException {
+        return getParsedOptionValue(String.valueOf(opt), defaultValue);
+    }
+
+    /**
+     * Gets a version of this {@code Option} converted to a particular type.
+     *
+     * @param option the name of the option.
+     * @param defaultValue the default value to return if opt is not set.
+     * @param <T> The return type for the method.
+     * @return the value parsed into a particular object.
+     * @throws ParseException if there are problems turning the option value into the desired type
+     * @see PatternOptionBuilder
+     * @since 1.7.0
+     */
+    @SuppressWarnings("unchecked")
+    public <T> T getParsedOptionValue(final Option option, final T defaultValue) throws ParseException {
         if (option == null) {
             return null;
         }
         final String res = getOptionValue(option);
-        if (res == null) {
-            return null;
+
+        try {
+            return res == null ? defaultValue : (T) option.getConverter().apply(res);
+        } catch (Exception e) {
+            throw ParseException.wrap(e);
         }
-        return TypeHandler.createValue(res, option.getType());
     }
 
     /**
      * Gets a version of this {@code Option} converted to a particular type.
      *
      * @param opt the name of the option.
+     * @param defaultValue the default value to return if opt is not set.
+     * @param <T> The return type for the method.
      * @return the value parsed into a particular object.
      * @throws ParseException if there are problems turning the option value into the desired type
      * @see PatternOptionBuilder
-     * @since 1.2
+     * @since 1.7.0
      */
-    public Object getParsedOptionValue(final String opt) throws ParseException {
-        return getParsedOptionValue(resolveOption(opt));
+    public <T> T getParsedOptionValue(final String opt, final T defaultValue) throws ParseException {
+        return getParsedOptionValue(resolveOption(opt), defaultValue);
     }
 
     /**

src/main/java/org/apache/commons/cli/Converter.java

@@ -0,0 +1,78 @@
+/*
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You 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.apache.commons.cli;
+
+import java.io.File;
+import java.net.URL;
+import java.nio.file.Path;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+/**
+ * The definition of the functional interface to call when doing a conversion.
+ * Like {@code Function<String,T>} but can throw an Exception.
+ *
+ * @param <T> The return type for the function.
+ * @since 1.7.0
+ */
+@FunctionalInterface
+public interface Converter<T> {
+
+    /** The default converter. Does nothing. */
+    Converter<?> DEFAULT = s -> s;
+
+    /** Class name converter. Calls {@code Class.forName}. */
+    Converter<Class<?>> CLASS = s -> Class.forName(s);
+
+    /** File name converter. Calls @{code new File(s)} */
+    Converter<File> FILE = s -> new File(s);
+
+    /** Path converter. Calls @{code new Path(s)} */
+    Converter<Path> PATH = s -> new File(s).toPath();
+
+    /**
+     * Number converter. Converts to a Double if a decimal point ('.') is in the
+     * string or a Long otherwise.
+     */
+    Converter<Number> NUMBER = s -> {
+        if (s.indexOf('.') != -1) {
+            return Double.valueOf(s);
+        }
+        return Long.valueOf(s);
+    };
+
+    /**
+     * Converts a class name to an instance of the class. Uses the Class converter
+     * to find the class and then call the default constructor.
+     * @see #CLASS
+     */
+    Converter<Object> OBJECT = s -> CLASS.apply(s).getConstructor().newInstance();
+
+    /** Creates a URL. Calls {@code new URL(s)}. */
+    Converter<URL> URL = s -> new URL(s);
+
+    /** Converts to a date using the format string Form "EEE MMM dd HH:mm:ss zzz yyyy". */
+    Converter<Date> DATE = s -> new SimpleDateFormat("EEE MMM dd HH:mm:ss zzz yyyy").parse(s);
+
+    /**
+     * Applies the conversion function to the String argument.
+     * @param  str       the String to convert
+     * @return           the Object from the conversion.
+     * @throws Exception on error.
+     */
+    T apply(String str) throws Exception;
+}

src/main/java/org/apache/commons/cli/Option.java

@@ -82,6 +82,9 @@ public static final class Builder {
 
         /** The character that is the value separator */
         private char valueSeparator;
+
+        /** The converter to convert to type **/
+        private Converter<?> converter;
 
         /**
          * Constructs a new {@code Builder} with the minimum required parameters for an {@code Option} instance.
@@ -270,6 +273,19 @@ public Builder valueSeparator(final char valueSeparator) {
             this.valueSeparator = valueSeparator;
             return this;
         }
+
+        /**
+         * Sets the converter for the option.
+         * <p>Note: see {@link TypeHandler} for serialization discussion.</p>
+         * @param converter the Converter to use.
+         * @return this builder, to allow method chaining.
+         * @since 1.7.0
+         */
+        public Builder converter(final Converter<?> converter) {
+            this.converter = converter;
+            return this;
+        }
+
     }
 
     /** Specifies the number of argument values has not been specified */
@@ -335,6 +351,9 @@ public static Builder builder(final String option) {
 
     /** The character that is the value separator. */
     private char valuesep;
+
+    /** The explicit converter for this option.  May be null */
+    private transient Converter<?> converter;
 
     /**
      * Private constructor used by the nested Builder class.
@@ -351,6 +370,7 @@ private Option(final Builder builder) {
         this.required = builder.required;
         this.type = builder.type;
         this.valuesep = builder.valueSeparator;
+        this.converter = builder.converter;
     }
 
     /**
@@ -423,7 +443,6 @@ private void add(final String value) {
         if (!acceptsArg()) {
             throw new IllegalArgumentException("Cannot add value, list full.");
         }
-
         // store value
         values.add(value);
     }
@@ -695,6 +714,8 @@ private boolean hasNoValues() {
     }
 
     /**
+     * Returns whether this Option can have an optional argument.
+     * 
      * @return whether this Option can have an optional argument
      */
     public boolean hasOptionalArg() {
@@ -865,6 +886,24 @@ public void setType(final Object type) {
     public void setValueSeparator(final char sep) {
         this.valuesep = sep;
     }
+
+    /**
+     * Gets the value to type converter.
+     * @return the value to type converter
+     * @since 1.7.0
+     */
+    public Converter<?> getConverter() {
+        return converter == null ? TypeHandler.getConverter(type) : converter;
+    }
+
+    /**
+     * Sets the value to type converter.
+     * @param converter The converter to convert the string value to the type.
+     * @since 1.7.0
+     */
+    public void setConverter(final Converter<?> converter) {
+        this.converter = converter;
+    }
 
     /**
      * Dump state, suitable for debugging.

src/main/java/org/apache/commons/cli/OptionBuilder.java

@@ -31,6 +31,7 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 @Deprecated
 public final class OptionBuilder {
 
+
     /** Long option */
     private static String longOption;
 
@@ -108,6 +109,7 @@ public static Option create(final String opt) throws IllegalArgumentException {
             option.setOptionalArg(optionalArg);
             option.setArgs(argCount);
             option.setType(type);
+            option.setConverter(TypeHandler.getConverter(type));
             option.setValueSeparator(valueSeparator);
             option.setArgName(argName);
         } finally {