craterdog.smart.SmartObjectMapper Maven / Gradle / Ivy

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/************************************************************************
 * Copyright (c) Crater Dog Technologies(TM).  All Rights Reserved.     *
 ************************************************************************
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.        *
 *                                                                      *
 * This code is free software; you can redistribute it and/or modify it *
 * under the terms of The MIT License (MIT), as published by the Open   *
 * Source Initiative. (See http://opensource.org/licenses/MIT)          *
 ************************************************************************/
package craterdog.smart;

import com.fasterxml.jackson.annotation.JsonInclude.Include;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.PrettyPrinter;
import com.fasterxml.jackson.core.util.DefaultIndenter;
import com.fasterxml.jackson.core.util.DefaultPrettyPrinter;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.Module;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.datatype.joda.JodaModule;

/**
 * This object mapper handles the conversion of a smart object to and from a JSON string. The mapper
 * can be configured to censor sensitive attributes that are marked with the @Sensitive
 * annotation.
 *
 * @author Jeff Webb
 * @author Mukesh Jyothi
 * @author Derk Norton
 */
@SuppressWarnings("serial")
class SmartObjectMapper extends ObjectMapper {

    /**
     * This constructor creates a new smart object mapper for the specified modules.
     *
     * @param modules The modules to be registered.
     */
    SmartObjectMapper(Module... modules) {
        super();

        // indent the output
        enable(SerializationFeature.INDENT_OUTPUT);

        // allow empty beans
        disable(SerializationFeature.FAIL_ON_EMPTY_BEANS);

        // don't serialize nulls
        disable(SerializationFeature.WRITE_NULL_MAP_VALUES);
        setSerializationInclusion(Include.NON_NULL);

        // don't fail on unknown properties
        configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

        // write dates out as string (not milliseconds since epoch <- timestamp)
        disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);

        // handle joda types
        registerModule(new JodaModule());

        // handle primitive types that can generate strings
        addMixIn(craterdog.primitives.BinaryString.class, UseToStringAsValueMixIn.class);
        addMixIn(craterdog.primitives.Tag.class, UseToStringAsValueMixIn.class);
        addMixIn(craterdog.primitives.TextString.class, UseToStringAsValueMixIn.class);
        addMixIn(java.net.URI.class, UseToStringAsValueMixIn.class);

        // handle primitive types that can generate doubles
        addMixIn(craterdog.primitives.Angle.class, UseToDoubleAsValueMixIn.class);
        addMixIn(craterdog.primitives.Probability.class, UseToDoubleAsValueMixIn.class);

        // add any additional modules passed in
        for (Module module : modules) {
            registerModule(module);
        }

        setDefaultPrettyPrinter(new BetterPrettyPrinter().withArrayIndenter(new DefaultIndenter()));
    }


    /**
     * This method behaves similarly to the writeValueAsString(Object value) method
     * except that it includes an indentation prefix that will be prepended to each line of the
     * resulting string (except the first line).
     *
     * @param value The smart object to be written out as a string.
     * @param indentation The indentation string to be prepended to each line.
     * @return The formatted string.
     * @throws JsonProcessingException The JSON object mapper was not able to serialize the object.
     */
    String writeValueAsString(Object value, String indentation) throws JsonProcessingException {
        PrettyPrinter printer = new BetterPrettyPrinter(indentation).withArrayIndenter(new DefaultIndenter());
        return writer(printer).writeValueAsString(value);
    }


    private class BetterPrettyPrinter extends DefaultPrettyPrinter {

        BetterPrettyPrinter() {
            super();
        }

        BetterPrettyPrinter(String indentation) {
            super();
            _nesting = indentation.length() / 2;  // two spaces per level
        }

    }

}