org.apache.drill.exec.ref.rse.JSONDataWriter.java Source code

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Here is the source code for org.apache.drill.exec.ref.rse.JSONDataWriter.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.drill.exec.ref.rse;

import java.io.IOException;
import java.io.OutputStream;

import org.apache.drill.exec.ref.rops.DataWriter;

import com.fasterxml.jackson.core.JsonEncoding;
import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonGenerator;

public class JSONDataWriter implements DataWriter {
    static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(JSONDataWriter.class);

    private final JsonGenerator g;
    //  private CharSequence transientName;

    public JSONDataWriter(OutputStream out) throws IOException {
        JsonFactory f = new JsonFactory();

        this.g = f.createJsonGenerator(out, JsonEncoding.UTF8);
        this.g.useDefaultPrettyPrinter();
    }

    private String s(CharSequence seq) {
        String s = (seq instanceof String) ? (String) seq : seq.toString();
        return s;
    }

    @Override
    public void startRecord() throws IOException {

    }

    @Override
    public void writeArrayStart(int length) throws IOException {
        g.writeStartArray();
    }

    @Override
    public void writeArrayElementStart() throws IOException {
    }

    @Override
    public void writeArrayElementEnd() throws IOException {
    }

    @Override
    public void writeArrayEnd() throws IOException {
        g.writeEndArray();
    }

    @Override
    public void writeMapStart() throws IOException {
        g.writeStartObject();
    }

    @Override
    public void writeMapKey(CharSequence seq) throws IOException {
        g.writeFieldName(s(seq));
    }

    @Override
    public void writeMapValueStart() throws IOException {
    }

    @Override
    public void writeMapValueEnd() throws IOException {
    }

    @Override
    public void writeMapEnd() throws IOException {
        g.writeEndObject();
    }

    @Override
    public void writeBoolean(boolean b) throws IOException {
        g.writeBoolean(b);
    }

    @Override
    public void writeSInt32(int value) throws IOException {
        g.writeNumber(value);
    }

    @Override
    public void writeSInt64(long value) throws IOException {
        g.writeNumber(value);
    }

    @Override
    public void writeBytes(byte[] bytes) throws IOException {
        g.writeBinary(bytes);
    }

    @Override
    public void writeSFloat64(double value) throws IOException {
        g.writeNumber(value);
    }

    @Override
    public void writeSFloat32(float value) throws IOException {
        g.writeNumber(value);
    }

    @Override
    public void writeNullValue() throws IOException {
        g.writeNull();
    }

    @Override
    public void writeCharSequence(CharSequence value) throws IOException {
        g.writeString(s(value));
    }

    @Override
    public void endRecord() throws IOException {
        g.writeRawValue("\n");
    }

    public void finish() throws IOException {
        g.close();
    }

}