webbeta / Serializer

import com.fasterxml.jackson.core.JsonFactory;

import com.fasterxml.jackson.core.JsonGenerator;

import es.webbeta.serializer.*;

import es.webbeta.serializer.base.FieldFormatter;

import es.webbeta.serializer.base.Logger;

import es.webbeta.serializer.base.ParentFieldData;

import es.webbeta.serializer.base.SerializerMetadataProvider;

import es.webbeta.serializer.type.DateFormatType;

import es.webbeta.serializer.type.FieldAccessType;

import java.io.IOException;

import java.io.StringWriter;

import java.math.BigDecimal;

import java.math.BigInteger;

import java.text.SimpleDateFormat;

import java.util.Date;

import java.util.Map;

public class Serializer {

    private final ConfigurationManager configurationManager;

    private SerializerMetadataProvider provider;

    private FieldFormatter formatter;

    private TypeChecker typeChecker;

    private JsonGenerator generator;

    private StringWriter writer;

    private Logger logger;

    Serializer(ConfigurationManager configurationManager) {

        this.configurationManager = configurationManager;

        formatter = configurationManager.getFieldFormatter();

    }

    public void setLogger(Logger logger) {

        this.logger = logger;

    }

    /**

     * Inits serialization context

     *

     * @return True if it went ok

     */

    private Boolean initializeGenerator() {

        writer = new StringWriter();

        JsonFactory factory = new JsonFactory();

        provider = configurationManager.newMetadataProvider();

        typeChecker = new TypeChecker(provider);

        try {

            generator = factory.createGenerator(writer);

            return true;

        } catch (IOException e) {

            generator = null;

            return false;

        }

    }

    private FieldAccessor buildFieldAccessor(Object ob, String fieldName) {

        Class<?> klass = ob.getClass();

        FieldAccessType accessType = configurationManager.getAccessType();

        if (provider.hasAccessType(klass))

            accessType = provider.getAccessType(klass);

        if (provider.hasPropertyAccessType(klass, fieldName))

            accessType = provider.getPropertyAccessType(klass, fieldName);

        String customGetter = provider.getPropertyCustomGetterName(klass, fieldName);

        FieldAccessor fieldAccessor = new FieldAccessor(ob, fieldName, accessType);

        fieldAccessor.setCustomGetterName(customGetter);

        if (logger != null) {

            fieldAccessor.setLogger(logger);

        }

        if (provider.isVirtualProperty(klass, fieldName))

            fieldAccessor.setEnsureFieldExists(false);

        return fieldAccessor;

    }

    private String getSerializedName(Class<?> klass, String fieldName) {

        String finalFieldName = formatter.format(fieldName);

        if (provider.hasPropertySerializedName(klass, fieldName))

            finalFieldName = provider.getPropertySerializedName(klass, fieldName);

        return finalFieldName;

    }

    private void fillDateValue(JsonGenerator gen, final Date date) throws IOException {

        if (configurationManager.getDateFormatType() == DateFormatType.ISO8601) {

            SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");

            gen.writeString(format.format(date));

        } else if (configurationManager.getDateFormatType() == DateFormatType.UNIX_TIMESTAMP)

            gen.writeNumber(date.getTime());

    }

    private void fillRawValue(JsonGenerator gen, final ParentFieldData parentFieldData, final Object value, final String[] group) throws IOException {

        typeChecker.check(value, new TypeCallback() {

            @Override

            public void itsByte(Byte value) throws IOException {

                gen.writeNumber(value);

            }

            @Override

            public void itsShort(Short value) throws IOException {

                gen.writeNumber(value);

            }

            @Override

            public void itsInteger(Integer value) throws IOException {

                gen.writeNumber(value);

            }

            @Override

            public void itsBigInteger(BigInteger value) throws IOException {

                gen.writeNumber(value);

            }

            @Override

            public void itsLong(Long value) throws IOException {

                gen.writeNumber(value);

            }

            @Override

            public void itsFloat(Float value) throws IOException {

                gen.writeNumber(value);

            }

            @Override

            public void itsDouble(Double value) throws IOException {

                gen.writeNumber(value);

            }

            @Override

            public void itsBigDecimal(BigDecimal value) throws IOException {

                gen.writeNumber(value);

            }

            @Override

            public void itsString(String value) throws IOException {

                gen.writeString(value);

            }

            @Override

            public void itsStringParseable(Object value) throws IOException {

                gen.writeString(value.toString());

            }

            @Override

            public void itsBoolean(Boolean value) throws IOException {

                gen.writeBoolean(value);

            }

            @Override

            public void itsSerializableObject(Object value) throws IOException {

                if (parentFieldData != null && parentFieldData.getKlass() == value.getClass()) {

                    fillWith(false, gen, parentFieldData, value, parentFieldData.getGroups());

                } else

                    fillWith(false, gen, parentFieldData, value, group);

            }

            @Override

            public void itsIterable(Iterable<?> value) throws IOException {

                gen.writeStartArray();

                for (Object arrValue : value) {

                    String[] parentGroups = provider.getGroupsByFieldName(parentFieldData.getKlass(), parentFieldData.getFieldName());

                    es.webbeta.serializer.ParentFieldData fieldData =

                            new es.webbeta.serializer.ParentFieldData(parentFieldData.getKlass(), parentFieldData.getFieldName(), parentGroups);

                    fillRawValue(gen, fieldData, arrValue, group);

                }

                gen.writeEndArray();

            }

            @Override

            public void itsMap(Map<?, ?> value) throws IOException {

                gen.writeStartObject();

                for (Map.Entry<?, ?> entry : value.entrySet()) {

                    String[] parentGroups = provider.getGroupsByFieldName(parentFieldData.getKlass(), parentFieldData.getFieldName());

                    es.webbeta.serializer.ParentFieldData fieldData =

                            new es.webbeta.serializer.ParentFieldData(parentFieldData.getKlass(), parentFieldData.getFieldName(), parentGroups);

                    gen.writeFieldName(entry.getKey().toString());

                    fillRawValue(gen, fieldData, entry.getValue(), group);

                }

                gen.writeEndObject();

            }

        });

    }

    private void fillWith(Boolean asArray, JsonGenerator gen, final ParentFieldData parentData, final Object ob, final String[] group) throws IOException {

        Class<?> klass = ob.getClass();

        String[] fields = provider.getPropertiesByGroup(klass, parentData, group);

        if (asArray)

            gen.writeStartArray();

        else

            gen.writeStartObject();

        if (typeChecker.isSerializableObject(ob)) {

            for (String fieldName : fields) {

                FieldAccessor accessor = buildFieldAccessor(ob, fieldName);

                if (accessor.get() == null) {

                    if (accessor.exists() && configurationManager.getIncludeNullValues()) {

                        gen.writeFieldName(getSerializedName(klass, fieldName));

                        gen.writeNull();

                    }

                    continue;

                }

                if (!typeChecker.isUnserializableObject(accessor.get())) {

                    es.webbeta.serializer.ParentFieldData fieldData =

                            new es.webbeta.serializer.ParentFieldData(klass, fieldName, group);

                    gen.writeFieldName(getSerializedName(klass, fieldName));

                    fillRawValue(gen, fieldData, accessor.get(), group);

                }

            }

        } else if (typeChecker.isIterable(ob)) {

            for (Object arrValue : (Iterable<?>) ob) {

                es.webbeta.serializer.ParentFieldData fieldData =

                        new es.webbeta.serializer.ParentFieldData(arrValue.getClass(), null, group);

                fillRawValue(gen, fieldData, arrValue, group);

            }

        }

        if (asArray)

            gen.writeEndArray();

        else

            gen.writeEndObject();

    }

    /**

     * It serializes an object without specifing serialization groups

     *

     * @param ob Object to serialize

     * @return JSON format string representing the object

     */

    public <T> String serialize(T ob) {

        return serialize(ob, new String[0]);

    }

    /**

     * It serializes an object specifing serialization groups

     *

     * @param ob    Object to serialize

     * @param group Serialization group or groups

     * @return JSON format string representing the object

     */

    public <T> String serialize(T ob, String... group) {

        if (ob == null) return null;

        if (!initializeGenerator())

            return null;

        try {

            fillWith(typeChecker.isIterable(ob), generator, null, ob, group);

            generator.close();

            return writer.toString();

        } catch (IOException e) {

            return null;

        }

    }

}