Replace Gson with Jackson.

# Changes in version 2.0.3 - 2018-0?-??

 * Medium changes

   - Replace Gson with Jackson.

 * Minor changes

   - Remove duplicate [] surrounding suggested IPv6 addresses.

  <property name="javadoc-title" value="ExoneraTor API Documentation"/>

  <property name="implementation-title" value="ExoneraTor" />

  <property name="release.version" value="2.0.2-dev" />

  <property name="metricslibversion" value="2.1.1" />

  <property name="metricslibversion" value="2.4.0" />

  <property name="jetty.version" value="-9.2.21.v20170120" />

  <property name="warfile"

            value="exonerator-${release.version}.war"/>

  <patternset id="common" >

    <include name="commons-codec-1.10.jar"/>

    <include name="commons-lang3-3.5.jar"/>

    <include name="gson-2.4.jar" />

    <include name="jackson-annotations-2.8.6.jar"/>

    <include name="jackson-core-2.8.6.jar"/>

    <include name="jackson-databind-2.8.6.jar"/>

    <include name="logback-core-1.1.9.jar" />

    <include name="logback-classic-1.1.9.jar" />

    <include name="postgresql-9.4.1212.jar"/>

package org.torproject.metrics.exonerator;

import com.google.gson.Gson;

import com.google.gson.annotations.Expose;

import com.google.gson.annotations.SerializedName;

import com.fasterxml.jackson.annotation.JsonAutoDetect;

import com.fasterxml.jackson.annotation.JsonInclude;

import com.fasterxml.jackson.annotation.PropertyAccessor;

import com.fasterxml.jackson.databind.ObjectMapper;

import com.fasterxml.jackson.databind.PropertyNamingStrategy;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import java.io.IOException;

import java.io.Reader;

/** Query response from the ExoneraTor database. */

public class QueryResponse {

  @Expose(serialize = false, deserialize = false)

  private static Logger logger = LoggerFactory.getLogger(QueryResponse.class);

  /* Actual version implemented by this class. */

  @Expose(serialize = false, deserialize = false)

  private static final String VERSION = "1.0";

  /* Don't accept query responses with versions lower than this. */

  @Expose(serialize = false, deserialize = false)

  private static final String FIRSTRECOGNIZEDVERSION = "1.0";

  /* Don't accept query responses with this version or higher. */

  @Expose(serialize = false, deserialize = false)

  private static final String FIRSTUNRECOGNIZEDVERSION = "2.0";

  private static ObjectMapper objectMapper = new ObjectMapper()

      .setPropertyNamingStrategy(PropertyNamingStrategy.SNAKE_CASE)

      .setSerializationInclusion(JsonInclude.Include.NON_EMPTY)

      .setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.NONE)

      .setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);

  /** Version of this response format. */

  @Expose

  String version = VERSION;

  /** Query IP address passed in the request; never <code>null</code>. */

  @Expose

  @SerializedName("query_address")

  String queryAddress;

  /** Query date passed in the request; never <code>null</code>. */

  @Expose

  @SerializedName("query_date")

  String queryDate;

  /** ISO-formatted valid-after time of the first status contained in the

   * database; only <code>null</code> if the database is empty. */

  @Expose

  @SerializedName("first_date_in_database")

  String firstDateInDatabase;

  /** ISO-formatted valid-after time of the last status contained in the

   * database; only <code>null</code> if the database is empty. */

  @Expose

  @SerializedName("last_date_in_database")

  String lastDateInDatabase;

  /** Whether there is at least one relevant status in the database on or within

   * a day of the requested date; <code>null</code> if the database is empty. */

  @Expose

  @SerializedName("relevant_statuses")

  Boolean relevantStatuses;

  /** All matches for the given IP address and date; <code>null</code> if there

   * were no matches at all. */

  @Expose

  Match[] matches;

  /** Constructor for Gson. */

  }

  /** Return JSON string for given QueryResponse. */

  public static String toJson(QueryResponse response) {

    return new Gson().toJson(response);

  public static String toJson(QueryResponse response) throws IOException {

    return objectMapper.writeValueAsString(response);

  }

  /** Return QueryResponse parsed from the given input stream, or

   * {@code null} if something fails or an unrecognized version is found. */

  public static QueryResponse fromJson(Reader reader) {

    Gson gson = new Gson();

    try {

      QueryResponse response = gson.fromJson(reader, QueryResponse.class);

      QueryResponse response = objectMapper.readValue(reader,

          QueryResponse.class);

      if (null == response || null == response.version) {

        logger.warn("Response is either empty or does not contain "

            + "version information.");

        return null;

      }

      return response;

    } catch (RuntimeException e) {

    } catch (IOException | RuntimeException e) {

      /* We're catching RuntimeException here, rather than IOException, so that

       * we return null if anything goes wrong, including cases that we did not

       * anticipate. */

      logger.error("JSON decoding failed.", e);

    }

    return null;

  /** All known IP addresses in the same /24 or /48 network; <code>null</code>

   * if there were direct matches for the given IP address. */

  @Expose

  @SerializedName("nearby_addresses")

  String[] nearbyAddresses;

}

import org.junit.runners.Parameterized;

import org.junit.runners.Parameterized.Parameters;

import java.io.IOException;

import java.io.StringReader;

import java.util.Arrays;

import java.util.Collection;

  }

  @Test

  public void testJsonReading() {

  public void testJsonReading() throws IOException {

    if (null == this.queryResponse) {

      assertNull(QueryResponse.fromJson(new StringReader(this.json)));

    } else {

  }

  @Test

  public void testJsonWriting() {

  public void testJsonWriting() throws IOException {

    if (null == this.queryResponse) {

      return;

    }