org.apache.ibatis.ognl.PropertyAccessor Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of mybatis Show documentation

The MyBatis SQL mapper framework makes it easier to use a relational database with object-oriented applications. MyBatis couples objects with stored procedures or SQL statements using a XML descriptor or annotations. Simplicity is the biggest advantage of the MyBatis data mapper over object relational mapping tools.

The newest version!

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.ibatis.ognl;

/**
 * This interface defines methods for setting and getting a property from a target object. A
 * "property" in this case is a named data value that takes the generic form of an Object---the same
 * definition as is used by beans. But the operational semantics of the term will vary by
 * implementation of this interface: a bean-style implementation will get and set properties as
 * beans do, by reflection on the target object's class, but other implementations are possible,
 * such as one that uses the property name as a key into a map.
 * 
 * An implementation of this interface will often require that its target objects all be of some
 * particular type. For example, the MapPropertyAccessor class requires that its targets all
 * implement the java.util.Map interface.
 * 
 * Note that the "name" of a property is represented by a generic Object. Some implementations may
 * require properties' names to be Strings, while others may allow them to be other types---for
 * example, ArrayPropertyAccessor treats Number names as indexes into the target object, which must
 * be an array.
 */
public interface PropertyAccessor {

    /**
     * Extracts and returns the property of the given name from the given target object.
     *
     * @param context The current execution context.
     * @param target  the object to get the property from
     * @param name    the name of the property to get.
     * @return the current value of the given property in the given object
     * @throws OgnlException if there is an error locating the property in the given object
     */
    Object getProperty(OgnlContext context, Object target, Object name) throws OgnlException;

    /**
     * Sets the value of the property of the given name in the given target object.
     *
     * @param context The current execution context.
     * @param target  the object to set the property in
     * @param name    the name of the property to set
     * @param value   the new value for the property.
     * @throws OgnlException if there is an error setting the property in the given object
     */
    void setProperty(OgnlContext context, Object target, Object name, Object value) throws OgnlException;

    /**
     * Returns a java string representing the textual method that should be called to access a
     * particular element. (ie "get")
     *
     * @param context The current execution context.
     * @param target  The current object target on the expression tree being evaluated.
     * @param index   The index object that will be placed inside the string to access the value.
     * @return The source accessor method to call.
     */
    String getSourceAccessor(OgnlContext context, Object target, Object index);

    /**
     * Returns a java string representing the textual method that should be called to set a
     * particular element. (ie "set")
     *
     * @param context The current execution context.
     * @param target  The current object target on the expression tree being evaluated.
     * @param index   The index object that will be placed inside the string to set the value.
     * @return The source setter method to call.
     */
    String getSourceSetter(OgnlContext context, Object target, Object index);
}