com.twitter.common.thrift.text.SequenceContext.java Source code

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Here is the source code for com.twitter.common.thrift.text.SequenceContext.java

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// =================================================================================================
// Copyright 2011 Twitter, Inc.
// -------------------------------------------------------------------------------------------------
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this work except in compliance with the License.
// You may obtain a copy of the License in the LICENSE file, or 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.twitter.common.thrift.text;

import java.util.Iterator;

import com.google.gson.JsonArray;
import com.google.gson.JsonElement;

/**
 * A parsing context used for Sequences (lists & sets). Maintains its
 * child elements, and a pointer to the current one being parsed.
 *
 * @author Alex Roetter
 */
class SequenceContext extends BaseContext {

    private final Iterator<JsonElement> children;
    private JsonElement currentChild;

    /**
     * Create an iterator over the children. May be constructed with a null
     * JsonArray if we only use it for writing.
     */
    protected SequenceContext(JsonArray json) {
        children = (null != json) ? json.iterator() : null;
    }

    @Override
    protected void read() {
        if (!children.hasNext()) {
            throw new RuntimeException("Called SequenceContext.read() too many times!");
        }
        currentChild = children.next();
    }

    @Override
    protected JsonElement getCurrentChild() {
        return currentChild;
    }

    @Override
    protected boolean hasMoreChildren() {
        return children.hasNext();
    }
}