net.nan21.dnet.core.presenter.converter.AbstractDsConverter.java Source code

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Here is the source code for net.nan21.dnet.core.presenter.converter.AbstractDsConverter.java

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/** 
 * DNet eBusiness Suite
 * Copyright: 2013 Nan21 Electronics SRL. All rights reserved.
 * Use is subject to license terms.
 */
package net.nan21.dnet.core.presenter.converter;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.persistence.EntityManager;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.expression.ExpressionParser;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.expression.spel.support.StandardEvaluationContext;
import org.springframework.util.StringUtils;

import net.nan21.dnet.core.api.action.result.IDsConverter;
import net.nan21.dnet.core.api.annotation.RefLookups;
import net.nan21.dnet.core.presenter.AbstractPresenterBase;
import net.nan21.dnet.core.presenter.descriptor.DsDescriptor;

public abstract class AbstractDsConverter<M, E> extends AbstractPresenterBase implements IDsConverter<M, E> {

    final static Logger logger = LoggerFactory.getLogger(AbstractDsConverter.class);

    /**
     * Parser to resolve data-source model field -> entity path expressions.
     */
    private ExpressionParser parser;

    /**
     * Data-source model descriptor
     */
    private DsDescriptor<M> descriptor;

    /**
     * Reference lookups resolver for the model to entity conversion.
     */
    private ReflookupResolver<M, E> resolver;

    private Class<M> modelClass;

    private Class<E> entityClass;

    public AbstractDsConverter() {
        this.parser = new SpelExpressionParser();
    }

    @Override
    public List<M> entitiesToModels(List<E> entities, EntityManager em, List<String> fieldNames) throws Exception {
        List<M> result = new ArrayList<M>();
        Method[] methods = this.getModelClass().getMethods();
        int l = methods.length;
        Map<String, Method> setters = new HashMap<String, Method>();
        for (int i = 0; i < l; i++) {
            Method method = methods[i];
            if (method.getName().startsWith("set") && !method.getName().equals("set__clientRecordId__")) {
                String fieldName = StringUtils.uncapitalize(method.getName().substring(3));
                if (fieldNames == null || fieldNames.contains(fieldName)) {
                    setters.put(fieldName, method);
                }
            }
        }
        Map<String, String> refpaths = this.descriptor.getE2mConv();
        for (E e : entities) {
            M m = modelClass.newInstance();
            this.entityToModel_(e, m, em, setters, refpaths);
            result.add(m);
        }
        return result;
    }

    /**
     * Populate model fields from entity according to mappings.
     */
    @Override
    public void entityToModel(E e, M m, EntityManager em, List<String> fieldNames) throws Exception {
        Method[] methods = this.getModelClass().getMethods();
        int l = methods.length;
        Map<String, Method> setters = new HashMap<String, Method>();
        for (int i = 0; i < l; i++) {
            Method method = methods[i];
            if (method.getName().startsWith("set") && !method.getName().equals("set__clientRecordId__")) {
                String fieldName = StringUtils.uncapitalize(method.getName().substring(3));
                if (fieldNames == null || fieldNames.contains(fieldName)) {
                    setters.put(fieldName, method);
                }
            }
        }
        Map<String, String> refpaths = this.descriptor.getE2mConv();
        entityToModel_(e, m, em, setters, refpaths);
    }

    /**
     * Populate model fields from entity according to mappings.
     */

    protected void entityToModel_(E e, M m, EntityManager em, Map<String, Method> setters,
            Map<String, String> refpaths) throws Exception {

        StandardEvaluationContext context = new StandardEvaluationContext(e);

        for (Map.Entry<String, Method> entry : setters.entrySet()) {
            String fieldName = entry.getKey();
            Method method = entry.getValue();

            if (method.getName().startsWith("set") && !method.getName().equals("set__clientRecordId__")) {
                try {
                    method.invoke(m, parser.parseExpression(refpaths.get(fieldName)).getValue(context));
                } catch (Exception exc) {

                }
            }
        }
    }

    /**
     * Update entity fields with values from the model according to mappings.
     */
    @Override
    public void modelToEntity(M m, E e, boolean isInsert, EntityManager em) throws Exception {

        if (logger.isDebugEnabled()) {
            logger.debug("Model-to-entity conversion: {} -> {} ",
                    new String[] { this.modelClass.getSimpleName(), this.entityClass.getSimpleName() });
        }

        this.modelToEntityAttributes(m, e, isInsert, em);
        this.modelToEntityReferences(m, e, isInsert, em);
    }

    /**
     * Update entity attribute fields.
     * 
     * @param m
     * @param e
     * @param isInsert
     * @param entityService
     * @throws Exception
     */
    protected void modelToEntityAttributes(M m, E e, boolean isInsert, EntityManager em) throws Exception {
        StandardEvaluationContext context = new StandardEvaluationContext(m);
        Map<String, String> attrmap = this.descriptor.getM2eConv();
        Method[] methods = this.getEntityClass().getMethods();

        List<String> noInserts = this.descriptor.getNoInserts();
        List<String> noUpdates = this.descriptor.getNoUpdates();

        for (Method method : methods) {
            if (method.getName().startsWith("set")) {
                String fn = StringUtils.uncapitalize(method.getName().substring(3));
                boolean doit = true;
                if (attrmap.containsKey(fn)) {
                    String dsf = attrmap.get(fn);
                    if (isInsert && noInserts.contains(fn)) {
                        doit = false;
                    }
                    if (!isInsert && noUpdates.contains(fn)) {
                        doit = false;
                    }

                    try {
                        if (doit) {
                            method.invoke(e, parser.parseExpression(dsf).getValue(context));
                        }
                    } catch (Exception exc) {

                    }
                }
            }
        }
    }

    /**
     * Update entity reference fields.
     * 
     * @param m
     * @param e
     * @param isInsert
     * @param entityService
     * @throws Exception
     */
    protected void modelToEntityReferences(M m, E e, boolean isInsert, EntityManager em) throws Exception {
        if (this.getModelClass().isAnnotationPresent(RefLookups.class)) {

            if (this.resolver == null) {
                this.resolver = new ReflookupResolver<M, E>(this.modelClass, this.entityClass);
            }

            this.resolver.setApplicationContext(this.getApplicationContext());
            this.resolver.execute(m, e, isInsert, em);
        }
    }

    /**
     * Get the data-source class.
     * 
     * @return
     */
    public Class<M> getModelClass() {
        return this.modelClass;
    }

    /**
     * Set the data-source class.
     * 
     * @param clazz
     */
    public void setModelClass(Class<M> clazz) {
        this.modelClass = clazz;
    }

    /**
     * Get the entity class.
     * 
     * @return
     */
    public Class<E> getEntityClass() {
        return entityClass;
    }

    /**
     * Set the entity class.
     * 
     * @param entityClass
     */
    public void setEntityClass(Class<E> entityClass) {
        this.entityClass = entityClass;
    }

    /**
     * Set the data-source descriptor.
     * 
     * @param descriptor
     */
    public void setDescriptor(DsDescriptor<M> descriptor) {
        this.descriptor = descriptor;
    }

    /**
     * Get the data-source descriptor.
     * 
     * @return
     */
    public DsDescriptor<M> getDescriptor() {
        return descriptor;
    }

}