org.apache.solr.client.solrj.request.RequestWriter.java Source code

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Here is the source code for org.apache.solr.client.solrj.request.RequestWriter.java

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/*
 * 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.apache.solr.client.solrj.request;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.nio.charset.StandardCharsets;
import java.util.Collection;
import java.util.List;
import java.util.Map;

import org.apache.solr.client.solrj.SolrRequest;
import org.apache.solr.client.solrj.util.ClientUtils;
import org.apache.solr.common.util.ContentStream;

/**
 * A RequestWriter is used to write requests to Solr.
 * <p>
 * A subclass can override the methods in this class to supply a custom format in which a request can be sent.
 *
 *
 * @since solr 1.4
 */
public class RequestWriter {

    public interface ContentWriter {

        void write(OutputStream os) throws IOException;

        String getContentType();
    }

    /**
     * Use this to do a push writing instead of pull. If this method returns null
     * {@link org.apache.solr.client.solrj.request.RequestWriter#getContentStreams(SolrRequest)} is
     * invoked to do a pull write.
     */
    public ContentWriter getContentWriter(SolrRequest req) {
        if (req instanceof UpdateRequest) {
            UpdateRequest updateRequest = (UpdateRequest) req;
            if (isEmpty(updateRequest))
                return null;
            return new ContentWriter() {
                @Override
                public void write(OutputStream os) throws IOException {
                    OutputStreamWriter writer = new OutputStreamWriter(os, StandardCharsets.UTF_8);
                    updateRequest.writeXML(writer);
                    writer.flush();
                }

                @Override
                public String getContentType() {
                    return ClientUtils.TEXT_XML;
                }
            };
        }
        return req.getContentWriter(ClientUtils.TEXT_XML);
    }

    /**
     * @deprecated Use {@link #getContentWriter(SolrRequest)}.
     */
    @Deprecated
    public Collection<ContentStream> getContentStreams(SolrRequest req) throws IOException {
        if (req instanceof UpdateRequest) {
            return null;
        }
        return req.getContentStreams();
    }

    protected boolean isEmpty(UpdateRequest updateRequest) {
        return isNull(updateRequest.getDocuments()) && isNull(updateRequest.getDeleteByIdMap())
                && isNull(updateRequest.getDeleteQuery()) && updateRequest.getDocIterator() == null;
    }

    public String getPath(SolrRequest req) {
        return req.getPath();
    }

    public void write(SolrRequest request, OutputStream os) throws IOException {
        if (request instanceof UpdateRequest) {
            UpdateRequest updateRequest = (UpdateRequest) request;
            BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, StandardCharsets.UTF_8));
            updateRequest.writeXML(writer);
            writer.flush();
        }
    }

    public String getUpdateContentType() {
        return ClientUtils.TEXT_XML;
    }

    public static class StringPayloadContentWriter implements ContentWriter {
        public final String payload;
        public final String type;

        public StringPayloadContentWriter(String payload, String type) {
            this.payload = payload;
            this.type = type;
        }

        @Override
        public void write(OutputStream os) throws IOException {
            if (payload == null)
                return;
            os.write(payload.getBytes(StandardCharsets.UTF_8));
        }

        @Override
        public String getContentType() {
            return type;
        }
    }

    protected boolean isNull(List l) {
        return l == null || l.isEmpty();
    }

    protected boolean isNull(Map l) {
        return l == null || l.isEmpty();
    }
}