StringParam.java

/*
 * Copyright (c) 2011, Cloudera, Inc. All Rights Reserved.
 *
 * Cloudera, Inc. 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
 *
 * This software 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.cloudera.lib.wsrs;

import com.cloudera.lib.util.Check;

import java.text.MessageFormat;
import java.util.regex.Pattern;

public abstract class StringParam extends Param<String> {
  private Pattern pattern;

  public StringParam(String name, String str) {
    this(name, str, null);
  }

  public StringParam(String name, String str, Pattern pattern) {
    this.pattern = pattern;
    value = parseParam(name, str);
  }

  public String parseParam(String name, String str) {
    String ret = null;
    Check.notNull(name, "name");
    try {
      if (str != null) {
        str = str.trim();
        if (str.length() > 0) {
          return parse(str);
        }
      }
    }
    catch (Exception ex) {
      throw new IllegalArgumentException(
        MessageFormat.format("Parameter [{0}], invalid value [{1}], value must be [{2}]",
                             name, str, getDomain()));
    }
    return ret;
  }

  protected String parse(String str) throws Exception {
    if (pattern != null) {
      if (!pattern.matcher(str).matches()) {
        throw new IllegalArgumentException("Invalid value");
      }
    }
    return str;
  }

  @Override
  protected String getDomain() {
    return (pattern == null) ? "a string" : pattern.pattern();
  }
}