com.bedatadriven.rebar.persistence.mapping.PropertyMapping.java Source code

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Here is the source code for com.bedatadriven.rebar.persistence.mapping.PropertyMapping.java

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/*
 * Copyright 2009-2010 BeDataDriven (alex@bedatadriven.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.bedatadriven.rebar.persistence.mapping;

import org.json.JSONException;
import org.json.JSONStringer;

import java.lang.reflect.Method;
import java.util.List;

/**
 * Defines a mapping between an entity's property (one value)
 * and one or more SQL columns.
 *
 * @author Alex Bertram
 */
public abstract class PropertyMapping {

    protected boolean unique = false;
    protected boolean insertable = true;
    protected boolean updatable = true;
    protected boolean nullable = true;
    private String name;
    private String getterName;
    private String setterName;
    private TypeInfo type;

    public PropertyMapping(MethodInfo getterMethod) {

        this.getterName = getterMethod.getName();
        this.type = getterMethod.getReturnType();

        int prefixLen = getterName.startsWith("is") ? 2 : 3;
        setterName = "set" + getterName.substring(prefixLen);
        name = Character.toLowerCase(getterName.charAt(prefixLen)) + getterName.substring(prefixLen + 1);
    }

    public boolean isNullable() {
        return nullable;
    }

    public boolean isUnique() {
        return unique;
    }

    /**
     * Gets the name of the persistent property or field
     *
     * @return the name of the persistent property or field
     */
    public String getName() {
        return name;
    }

    public String getGetterName() {
        return getterName;
    }

    public TypeInfo getType() {
        return type;
    }

    public String getSetterName() {
        return setterName;
    }

    public boolean isId() {
        return false;
    }

    public boolean isAutoincrement() {
        return false;
    }

    /**
     * Gets the name of the convertor function to use when applying a value of this
     * property to a PreparedStatement
     *
     * @return the name of the convertor function to use when applying a value of this
     * property to a PreparedStatement
     */
    public String getConvertor() {
        return "";
    }

    /**
     * Returns true if the property/field is an embedded class
     *
     * @return
     */
    public boolean isEmbedded() {
        return false;
    }

    /**
     * Returns true if the property/field is an unboxed, primitive type
     *
     * @return true if the property/field is an unboxed, primitive type
     */
    public boolean isPrimitive() {
        return false;
    }

    /**
     * Returns true if this property/field is a related entity with a One-To-One or
     * Many-To-One relationship
     *
     * @return
     */
    public boolean isToOne() {
        return false;
    }

    /**
     * Gets the mapping
     *
     * @return
     */
    public EntityMapping getEmbeddedClass() {
        return null;
    }

    public EntityMapping getRelatedEntity() {
        return null;
    }

    public String callGetter(String varName) {
        return varName + "." + getterName + "()";
    }

    public boolean isInsertable() {
        return insertable;
    }

    public boolean isUpdatable() {
        return updatable;
    }

    public String getReaderName() {
        return null;
    }

    /**
     * Returns a list of SQL column types used to store this entity member.
     * (Most entity members are stored as a single column, but embedded columns, for example,
     * span several columns, and collections are not store in columns at all)
     *
     * @return the list of SQL column types in which to store this field.
     */
    public abstract List<ColumnMapping> getColumns();

    /**
     * Returns information on the column in which this persistent property/field is stored,
     * or null if this property/field is stored in several columns.
     *
     * @return information on the column in which this persistent property/field is stored,
     * or null if this property/field is stored in several columns.
     */
    public ColumnMapping getColumn() {
        List<ColumnMapping> columns = getColumns();
        if (columns.size() == 1)
            return columns.get(0);

        return null;
    }

    public abstract void writeColumnValues(JSONStringer writer, Object entity) throws JSONException;

    /**
     * Uses reflection to read the value of this property from an object
     * instance.
     *
     * @param instance The instance of a class to which this mapping is a member
     * @return The value of this field in the given instance
     */
    public Object getValue(Object instance) {
        Object value;
        try {
            Method getter = instance.getClass().getMethod(getGetterName());

            value = getter.invoke(instance);

        } catch (NullPointerException e) {
            value = null;
        } catch (Exception e) {
            throw new MappingException("Exception thrown while getting the value.\n" + "Field: " + getName() + "\n"
                    + "Mapping:" + this.toString(), e);
        }
        return value;
    }

}