converterregistry.java

JGraph扩展应用。自定义Renderer,自定义视图View实现自定义工作流控件

/**
 * @PROJECT.FULLNAME@ @VERSION@ License.
 *
 * Copyright @YEAR@ L2FProd.com
 *
 * 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.l2fprod.common.util.converter;

import java.util.HashMap;
import java.util.Map;

/**
 * ConverterRegistry. <br>
 *  
 */
public class ConverterRegistry implements Converter {

  private static ConverterRegistry sharedInstance = new ConverterRegistry();
  
  private Map fromMap;

  public ConverterRegistry() {
    fromMap = new HashMap();

    new BooleanConverter().register(this);
    new AWTConverters().register(this);
    new NumberConverters().register(this);
  }

  public void addConverter(Class from, Class to, Converter converter) {
    Map toMap = (Map)fromMap.get(from);
    if (toMap == null) {
      toMap = new HashMap();
      fromMap.put(from, toMap);
    }
    toMap.put(to, converter);
  }

  public Converter getConverter(Class from, Class to) {
    Map toMap = (Map)fromMap.get(from);
    if (toMap != null) {
      return (Converter)toMap.get(to);
    } else {
      return null;
    }
  }

  public Object convert(Class targetType, Object value) {
    if (value == null) {
      return null;
    }
    
    Converter converter = getConverter(value.getClass(), targetType);
    if (converter == null) {
      throw new IllegalArgumentException(
        "No converter from " + value.getClass() + " to " + targetType.getName());
    } else {
      return converter.convert(targetType, value);
    }
  }

  public static ConverterRegistry instance() {
    return sharedInstance;
  }

}