Expression.java

// MODIFIED FOR THE MSGPACK PROJECT
// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements.  See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF 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
// 
// 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.msgpack.template.builder.beans;

import org.apache.harmony.beans.BeansUtils;

public class Expression extends Statement {

    boolean valueIsDefined = false;

    Object value;

    public Expression(Object value, Object target, String methodName,
            Object[] arguments) {
        super(target, methodName, arguments);
        this.value = value;
        this.valueIsDefined = true;
    }

    public Expression(Object target, String methodName, Object[] arguments) {
        super(target, methodName, arguments);
        this.value = null;
        this.valueIsDefined = false;
    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        if (!valueIsDefined) {
            sb.append("<unbound>"); //$NON-NLS-1$
        } else {
            if (value == null) {
                sb.append(BeansUtils.NULL);
            } else {
                Class<?> clazz = value.getClass();
                sb.append(clazz == String.class ? BeansUtils.QUOTE : BeansUtils
                        .idOfClass(clazz));
            }
        }
        sb.append('=');
        sb.append(super.toString());
        return sb.toString();
    }

    public void setValue(Object value) {
        this.value = value;
        this.valueIsDefined = true;
    }

    public Object getValue() throws Exception {
        if (!valueIsDefined) {
            value = invokeMethod();
            valueIsDefined = true;
        }
        return value;
    }
}