com.cedarsoft.couchdb.io.ActionFailedExceptionSerializer.java Source code

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Here is the source code for com.cedarsoft.couchdb.io.ActionFailedExceptionSerializer.java

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/**
 * Copyright (C) cedarsoft GmbH.
 *
 * Licensed under the GNU General Public License version 3 (the "License")
 * with Classpath Exception; you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 *         http://www.cedarsoft.org/gpl3ce
 *         (GPL 3 with Classpath Exception)
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 3 only, as
 * published by the Free Software Foundation. cedarsoft GmbH designates this
 * particular file as subject to the "Classpath" exception as provided
 * by cedarsoft GmbH in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 3 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 3 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact cedarsoft GmbH, 72810 Gomaringen, Germany,
 * or visit www.cedarsoft.com if you need additional information or
 * have any questions.
 */

package com.cedarsoft.couchdb.io;

import com.cedarsoft.couchdb.core.ActionFailedException;
import com.cedarsoft.serialization.jackson.JacksonParserWrapper;
import com.cedarsoft.serialization.jackson.JacksonSupport;
import com.cedarsoft.version.VersionException;
import com.fasterxml.jackson.core.JsonEncoding;
import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import org.apache.commons.io.input.TeeInputStream;

import javax.annotation.Nonnull;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 *
 */
public class ActionFailedExceptionSerializer {
    @Nonnull
    public static final String PROPERTY_ERROR = "error";
    @Nonnull
    public static final String PROPERTY_REASON = "reason";

    public void serialize(@Nonnull ActionFailedException object, @Nonnull OutputStream out) throws IOException {
        JsonFactory jsonFactory = JacksonSupport.getJsonFactory();
        JsonGenerator generator = jsonFactory.createJsonGenerator(out, JsonEncoding.UTF8);

        generator.writeStartObject();

        serialize(generator, object);
        generator.writeEndObject();

        generator.close();
    }

    @Nonnull
    public ActionFailedException deserialize(int status, @Nonnull InputStream in)
            throws VersionException, IOException {
        try (MaxLengthByteArrayOutputStream teedOut = new MaxLengthByteArrayOutputStream();
                TeeInputStream teeInputStream = new TeeInputStream(in, teedOut)) {

            JsonFactory jsonFactory = JacksonSupport.getJsonFactory();

            JsonParser parser = jsonFactory.createJsonParser(teeInputStream);
            JacksonParserWrapper parserWrapper = new JacksonParserWrapper(parser);

            parserWrapper.nextToken(JsonToken.START_OBJECT);

            String error = null;
            String reason = null;

            while (parser.nextToken() == JsonToken.FIELD_NAME) {
                String currentName = parser.getCurrentName();

                if (currentName.equals(PROPERTY_ERROR)) {
                    parserWrapper.nextToken(JsonToken.VALUE_STRING);
                    error = parser.getText();
                    continue;
                }

                if (currentName.equals(PROPERTY_REASON)) {
                    parserWrapper.nextToken(JsonToken.VALUE_STRING);
                    reason = parser.getText();
                    continue;
                }

                throw new IllegalStateException("Unexpected field reached <" + currentName + ">");
            }

            parserWrapper.verifyDeserialized(error, PROPERTY_ERROR);
            parserWrapper.verifyDeserialized(reason, PROPERTY_REASON);
            assert reason != null;
            assert error != null;

            parserWrapper.ensureObjectClosed();

            return new ActionFailedException(status, error, reason, teedOut.toByteArray());
        }
    }

    public void serialize(@Nonnull JsonGenerator serializeTo, @Nonnull ActionFailedException object)
            throws IOException {
        serializeTo.writeStringField(PROPERTY_ERROR, object.getError());
        serializeTo.writeStringField(PROPERTY_REASON, object.getReason());
    }

}