internationalization

text-io/src/main/java/org/beryx/textio/BooleanInputReader.java

@@ -34,22 +34,22 @@ public BooleanInputReader(Supplier<TextTerminal<?>> textTerminalSupplier) {
 
     /** Configures the string value that corresponds to <i>true</i>. */
     public BooleanInputReader withTrueInput(String trueInput) {
-        if(trueInput == null || trueInput.trim().isEmpty()) throw new IllegalArgumentException("trueInput is empty");
+        if(trueInput == null || trueInput.trim().isEmpty()) throw new IllegalArgumentException(getMessage ("trueInput_is_empty"));
         this.trueInput = trueInput;
         return this;
     }
 
     /** Configures the string value that corresponds to <i>false</i>. */
     public BooleanInputReader withFalseInput(String falseInput) {
-        if(falseInput == null || falseInput.trim().isEmpty()) throw new IllegalArgumentException("falseInput is empty");
+        if(falseInput == null || falseInput.trim().isEmpty()) throw new IllegalArgumentException(getMessage ("falseInput_is_empty"));
         this.falseInput = falseInput;
         return this;
     }
 
     @Override
     protected List<String> getDefaultErrorMessages(String s) {
         List<String> errList = super.getDefaultErrorMessages(s);
-        errList.add("Expected: " + trueInput + " / " + falseInput);
+        errList.add(getMessage ("expected_boolean", trueInput, falseInput));
         return errList;
     }
 

text-io/src/main/java/org/beryx/textio/ByteInputReader.java

@@ -27,7 +27,7 @@ public ByteInputReader(Supplier<TextTerminal<?>> textTerminalSupplier) {
 
     @Override
     protected String typeNameWithIndefiniteArticle() {
-        return "a byte";
+        return getMessage ("a_byte");
     }
 
     @Override

text-io/src/main/java/org/beryx/textio/CharInputReader.java

@@ -27,7 +27,7 @@ public CharInputReader(Supplier<TextTerminal<?>> textTerminalSupplier) {
 
     @Override
     protected String typeNameWithIndefiniteArticle() {
-        return "a single character";
+        return getMessage ("a_single_character");
     }
 
     @Override

text-io/src/main/java/org/beryx/textio/ComparableInputReader.java

@@ -56,10 +56,11 @@ protected List<String> getMinMaxErrorMessage(T val) {
     }
 
     private String getStandardMinMaxErrorMessage() {
-        if(minVal != null && maxVal != null) return "Expected " + typeNameWithIndefiniteArticle() + " value between " + minVal + " and " + maxVal + ".";
-        if(minVal != null) return "Expected " + typeNameWithIndefiniteArticle() + " value greater than or equal to " + minVal + ".";
-        if(maxVal != null) return "Expected " + typeNameWithIndefiniteArticle() + " value less than or equal to " + maxVal + ".";
-        return "Expected " + typeNameWithIndefiniteArticle() + " value.";
+
+        if(minVal != null && maxVal != null) return getMessage ("expected_value_between_minVal_and_maxVal", typeNameWithIndefiniteArticle(), minVal, maxVal);
+        if(minVal != null) return getMessage ("expected_value_greater_than_or_equal_to_minVal", typeNameWithIndefiniteArticle(), minVal);
+        if(maxVal != null) return getMessage ("expected_value_less_than_or_equal_to_maxVal", typeNameWithIndefiniteArticle(), maxVal);
+        return getMessage ("expected_value", typeNameWithIndefiniteArticle());
     }
 
     /** In addition to the checks performed by {@link InputReader#checkConfiguration()}, it checks if minVal &lt;= maxVal */

text-io/src/main/java/org/beryx/textio/DoubleInputReader.java

@@ -27,7 +27,7 @@ public DoubleInputReader(Supplier<TextTerminal<?>> textTerminalSupplier) {
 
     @Override
     protected String typeNameWithIndefiniteArticle() {
-        return "a double";
+        return getMessage ("a_double");
     }
 
     @Override

text-io/src/main/java/org/beryx/textio/FloatInputReader.java

@@ -27,7 +27,7 @@ public FloatInputReader(Supplier<TextTerminal<?>> textTerminalSupplier) {
 
     @Override
     protected String typeNameWithIndefiniteArticle() {
-        return "a float";
+        return getMessage ("a_float");
     }
 
     @Override

text-io/src/main/java/org/beryx/textio/InputReader.java

@@ -15,13 +15,22 @@
  */
 package org.beryx.textio;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.Set;
 import java.util.function.BiFunction;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
+import org.beryx.textio.i18n.TextIoI18nLanguageCode;
+import org.beryx.textio.i18n.TextIoI18nService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -36,6 +45,8 @@ public abstract class InputReader<T, B extends InputReader<T, B>> {
 
     public static final String PROPS_PREFIX_ERROR_MESSAGE = "error";
 
+    private TextIoI18nLanguageCode i18nLanguageCode = null;
+
     /** Functional interface for providing error messages */
     @FunctionalInterface
     public interface ErrorMessagesProvider {
@@ -169,6 +180,16 @@ public InputReader(Supplier<TextTerminal<?>> textTerminalSupplier) {
         this.textTerminalSupplier = textTerminalSupplier;
     }
 
+    @SuppressWarnings ("unchecked")
+    public B withLanguageCode (TextIoI18nLanguageCode i18nLanguageCode) {
+        this.i18nLanguageCode = i18nLanguageCode;
+        return (B) this;
+    }
+
+    public TextIoI18nLanguageCode getLanguageCode () {
+        return i18nLanguageCode;
+    }
+
     @SuppressWarnings("unchecked")
     public B withDefaultValue(T defaultValue) {
         this.defaultValue = defaultValue;
@@ -331,13 +352,13 @@ public boolean isValueListMode() {
 
     /** Returns a generic error message. */
     protected String getDefaultErrorMessage(String sVal) {
-        StringBuilder errBuilder = new StringBuilder("Invalid value");
+        StringBuilder errBuilder = new StringBuilder (getMessage ("invalid_value"));
         if(valueListMode) {
-            errBuilder.append(" in the comma-separated list");
-            if(itemName != null) errBuilder.append(" of '").append(itemName).append("'");
+            errBuilder.append (" ").append (getMessage ("in_the_comma-separated_list"));
+            if (itemName != null) errBuilder.append (" ").append (getMessage ("of")).append (" '").append (itemName).append ("'");
             if(sVal != null && !sVal.isEmpty()) errBuilder.append(": ").append(sVal);
         } else {
-            if(itemName != null) errBuilder.append(" for '").append(itemName).append("'");
+            if (itemName != null) errBuilder.append (" ").append (getMessage ("or")).append (" '").append (itemName).append ("'");
         }
         errBuilder.append('.');
         return errBuilder.toString();
@@ -501,9 +522,9 @@ private T getValueFromString(String sVal, TextTerminal<?> textTerminal) {
                     String options = possibleValues.stream()
                             .map(val -> "'" + valueFormatter.apply(val) + "'")
                             .collect(Collectors.joining(", "));
-                    t.println(" Please enter one of: " + options + ".");
+                    t.println (" " + getMessage ("please_enter_one_of", options));
                 } else {
-                    t.println(" Please enter one of the displayed values.");
+                    t.println (" " + getMessage ("please_enter_one_of_the_displayed_values"));
                 }
             });
             textTerminal.println();
@@ -528,7 +549,7 @@ private T getValueFromIndex(String sVal, TextTerminal<?> textTerminal) {
                 textTerminal.println(invalidIndexErrorMessagesProvider.getErrorMessages(sVal, itemName, 1, possibleValues.size()));
             } else {
                 textTerminal.print(getDefaultErrorMessage(sVal));
-                textTerminal.println(" Enter a value between 1 and " + possibleValues.size() + ".");
+                textTerminal.println (" " + getMessage ("enter_a_value_between_1_and", possibleValues.size ()));
             }
         });
         textTerminal.println();
@@ -614,12 +635,12 @@ protected void printPrompt(List<String> prompt, TextTerminal<?> textTerminal) {
                         String[] textLines = optionText.split("\\R", -1);
                         if(textLines.length > 1) {
                             String delimiter = String.format("\n%" + (digits + 4) + "s", "");
-                            optionText = Arrays.stream(textLines).collect(Collectors.joining(delimiter));
+                            optionText = String.join (delimiter, textLines);
                         }
                     }
                     textTerminal.println((isDefault ? "* ": "  ") + optionId + optionText);
                 }
-                textTerminal.print(valueListMode ? "Enter your choices as comma-separated values: " : "Enter your choice: ");
+                textTerminal.print (valueListMode ? getMessage ("enter_your_choices_as_comma_separated_values") + " " : getMessage ("enter_your_choice") + " ");
             }
         }
     }
@@ -630,19 +651,23 @@ private static boolean shouldappendColon(String s) {
         return "()[]{}".indexOf(lastChar) > 0 || Character.isJavaIdentifierPart(lastChar);
     }
 
-    public static <T> ValueChecker<List<T>> nonEmptyListChecker() {
+    public ValueChecker<List<T>> nonEmptyListChecker () {
         return (list, propName) -> {
-            if(list == null || list.isEmpty()) return Collections.singletonList("Expected at least one element.");
+            if (list == null || list.isEmpty ()) return Collections.singletonList (getMessage ("expected_at_least_one_element"));
             else return null;
         };
     }
 
-    public static <T> ValueChecker<List<T>> noDuplicatesChecker() {
+    public ValueChecker<List<T>> noDuplicatesChecker () {
         return (list, propName) -> {
             if(list == null || list.size() < 2) return null;
             Set<T> valueSet = new HashSet<>(list);
-            if(valueSet.size() < list.size()) return Collections.singletonList("Duplicate values are not allowed.");
+            if (valueSet.size () < list.size ()) return Collections.singletonList ("duplicate_values_are_not_allowed");
             return null;
         };
     }
+
+    protected String getMessage (String messageKey, Object... args) {
+        return TextIoI18nService.getInstance ().getMessage (messageKey, getLanguageCode (), args);
+    }
 }

text-io/src/main/java/org/beryx/textio/IntInputReader.java

@@ -27,7 +27,7 @@ public IntInputReader(Supplier<TextTerminal<?>> textTerminalSupplier) {
 
     @Override
     protected String typeNameWithIndefiniteArticle() {
-        return "an integer";
+        return getMessage ("an_integer");
     }
 
     @Override

text-io/src/main/java/org/beryx/textio/LongInputReader.java

@@ -27,7 +27,7 @@ public LongInputReader(Supplier<TextTerminal<?>> textTerminalSupplier) {
 
     @Override
     protected String typeNameWithIndefiniteArticle() {
-        return "a long";
+        return getMessage ("a_long");
     }
 
     @Override

text-io/src/main/java/org/beryx/textio/ShortInputReader.java

@@ -27,7 +27,7 @@ public ShortInputReader(Supplier<TextTerminal<?>> textTerminalSupplier) {
 
     @Override
     protected String typeNameWithIndefiniteArticle() {
-        return "a short";
+        return getMessage ("a_short");
     }
 
     @Override

text-io/src/main/java/org/beryx/textio/StringInputReader.java

@@ -57,7 +57,7 @@ public StringInputReader withMaxLength(int maxLength) {
     }
 
     public StringInputReader withIgnoreCase() {
-        return withEqualsFunc((s1, s2) -> s1.equalsIgnoreCase(s2));
+        return withEqualsFunc (String::equalsIgnoreCase);
     }
 
     @Override
@@ -74,14 +74,14 @@ protected void checkConfiguration() throws IllegalArgumentException {
 
     protected List<String> getLengthValidationErrors(String s) {
         int len = (s == null) ? 0 : s.length();
-        IntFunction<String> chr = l -> l + " character" + ((l > 1) ? "s." : ".");
-        if(minLength > 0 && minLength > len) return Collections.singletonList("Expected a string with at least " + chr.apply(minLength));
-        if(maxLength > 0 && maxLength < len) return Collections.singletonList("Expected a string with at most " + chr.apply(maxLength));
+        IntFunction<String> chr = l -> l + " " + getMessage ("character") + ((l > 1) ? "s." : ".");
+        if (minLength > 0 && minLength > len) return Collections.singletonList (getMessage ("expected_a_string_with_at_least", chr.apply (minLength)));
+        if (maxLength > 0 && maxLength < len) return Collections.singletonList (getMessage ("expected_a_string_with_at_most", chr.apply (maxLength)));
         return null;
     }
 
     protected List<String> getPatternValidationErrors(String s) {
-        if((pattern != null) && !pattern.matcher(s).matches()) return Collections.singletonList("Expected format: " + pattern.pattern());
+        if ((pattern != null) && !pattern.matcher (s).matches ()) return Collections.singletonList (getMessage ("expected_format", pattern.pattern ()));
         return null;
     }
 }

text-io/src/main/java/org/beryx/textio/i18n/EnLanguageService.java

@@ -0,0 +1,39 @@
+package org.beryx.textio.i18n;
+
+import java.util.Objects;
+
+/*
+ * Copyright 2017 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.
+ */
+class EnLanguageService implements ILanguageService {
+
+    private EnLanguageService () {
+        super ();
+    }
+
+    private static class Holder {
+        private static final EnLanguageService INSTANCE = new EnLanguageService ();
+    }
+
+    private static class Messages {
+        private static final MessagesLoader INSTANCE = new MessagesLoader ("/org/beryx/textio/i18n/en.properties");
+    }
+
+    public static EnLanguageService getInstance () { return Holder.INSTANCE; }
+
+    @Override public String getMessage (String messageKey, Object... args) {
+        return String.format (Objects.requireNonNull (Messages.INSTANCE.getProperties ().getProperty (messageKey)), args);
+    }
+}

text-io/src/main/java/org/beryx/textio/i18n/ILanguageService.java

@@ -0,0 +1,21 @@
+package org.beryx.textio.i18n;
+
+/*
+ * Copyright 2017 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.
+ */
+public interface ILanguageService {
+
+    String getMessage (String messageKey, Object... args);
+}

text-io/src/main/java/org/beryx/textio/i18n/ItLanguageService.java

@@ -0,0 +1,39 @@
+package org.beryx.textio.i18n;
+
+import java.util.Objects;
+
+/*
+ * Copyright 2017 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.
+ */
+class ItLanguageService implements ILanguageService {
+
+    private ItLanguageService () {
+        super ();
+    }
+
+    private static class Holder {
+        private static final ItLanguageService INSTANCE = new ItLanguageService ();
+    }
+
+    private static class Messages {
+        private static final MessagesLoader INSTANCE = new MessagesLoader ("/org/beryx/textio/i18n/it.properties");
+    }
+
+    public static ItLanguageService getInstance () { return Holder.INSTANCE; }
+
+    @Override public String getMessage (String messageKey, Object... args) {
+        return String.format (Objects.requireNonNull (Messages.INSTANCE.getProperties ().getProperty (messageKey)), args);
+    }
+}