Import code from internal repository to git

java/com/google/domain/registry/tools/params/ParameterConverterValidator.java

@@ -0,0 +1,49 @@
+// Copyright 2016 Google Inc. All Rights Reserved.
+//
+// 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 com.google.domain.registry.tools.params;
+
+import com.beust.jcommander.IParameterValidator;
+import com.beust.jcommander.IStringConverter;
+import com.beust.jcommander.ParameterException;
+
+/** Base class for parameters that do both conversion and validation (reduces boilerplate). */
+public abstract class ParameterConverterValidator<T>
+    implements IStringConverter<T>, IParameterValidator {
+
+  private final String messageForInvalid;
+
+  ParameterConverterValidator() {
+    this("Validation failed.");
+  }
+
+  ParameterConverterValidator(String messageForInvalid) {
+    this.messageForInvalid = messageForInvalid;
+  }
+
+  @Override
+  public abstract T convert(String arg0);  // Redefine so non-null package annotation kicks in.
+
+  @Override
+  public void validate(String name, String value) throws ParameterException {
+    try {
+      convert(value);
+    } catch (IllegalArgumentException e) {
+      ParameterException pe =
+          new ParameterException(String.format("%s=%s %s", name, value, messageForInvalid));
+      pe.initCause(e);
+      throw pe;
+    }
+  }
+}