MapVariableResolver.java

/**
 * MVEL 2.0
 * Copyright (C) 2007 The Codehaus
 * Mike Brock, Dhanji Prasanna, John Graham, Mark Proctor
 *
 * 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 org.mvel2.integration.impl;

import org.mvel2.integration.VariableResolver;

import java.util.Map;

import static org.mvel2.DataConversion.canConvert;
import static org.mvel2.DataConversion.convert;

public class MapVariableResolver implements VariableResolver {
  private String name;
  private Class<?> knownType;
  private Map<String, Object> variableMap;

  public MapVariableResolver(Map<String, Object> variableMap, String name) {
    this.variableMap = variableMap;
    this.name = name;
  }

  public MapVariableResolver(Map<String, Object> variableMap, String name, Class knownType) {
    this.name = name;
    this.knownType = knownType;
    this.variableMap = variableMap;
  }

  public void setName(String name) {
    this.name = name;
  }

  public void setStaticType(Class knownType) {
    this.knownType = knownType;
  }

  public void setVariableMap(Map<String, Object> variableMap) {
    this.variableMap = variableMap;
  }

  public String getName() {
    return name;
  }

  public Class getType() {
    return knownType;
  }

  public void setValue(Object value) {
    if (knownType != null && value != null && value.getClass() != knownType) {
      if (!canConvert(knownType, value.getClass())) {
        throw new RuntimeException("cannot assign " + value.getClass().getName() + " to type: "
            + knownType.getName());
      }
      try {
        value = convert(value, knownType);
      }
      catch (Exception e) {
        throw new RuntimeException("cannot convert value of " + value.getClass().getName()
            + " to: " + knownType.getName());
      }
    }

    //noinspection unchecked
    variableMap.put(name, value);
  }

  public Object getValue() {
    return variableMap.get(name);
  }

  public int getFlags() {
    return 0;
  }
}