fieldexpressionvalidator.java

在Struts2中的jar包xwork的源代码.版本为2.0.7

/*
 * Copyright (c) 2002-2006 by OpenSymphony
 * All rights reserved.
 */

package com.opensymphony.xwork2.validator.annotations;

import java.lang.annotation.*;

/**
 * <!-- START SNIPPET: description -->
 * This validator uses an OGNL expression to perform its validator.
 * The error message will be added to the field if the expression returns
 * false when it is evaluated against the value stack.
 * <!-- END SNIPPET: description -->
 *
 * <p/> <u>Annotation usage:</u>
 *
 * <!-- START SNIPPET: usage -->
 * <p/>The annotation must be applied at method level.
 * <!-- END SNIPPET: usage -->
 *
 * <p/> <u>Annotation parameters:</u>
 *
 * <!-- START SNIPPET: parameters -->
 * <table class='confluenceTable'>
 * <tr>
 * <th class='confluenceTh'> Parameter </th>
 * <th class='confluenceTh'> Required </th>
 * <th class='confluenceTh'> Default </th>
 * <th class='confluenceTh'> Notes </th>
 * </tr>
 * <tr>
 * <td class='confluenceTd'>message</td>
 * <td class='confluenceTd'>yes</td>
 * <td class='confluenceTd'>&nbsp;</td>
 * <td class='confluenceTd'>field error message</td>
 * </tr>
 * <tr>
 * <td class='confluenceTd'>key</td>
 * <td class='confluenceTd'>no</td>
 * <td class='confluenceTd'>&nbsp;</td>
 * <td class='confluenceTd'>i18n key from language specific properties file.</td>
 * </tr>
 * <tr>
 * <td class='confluenceTd'>fieldName</td>
 * <td class='confluenceTd'>no</td>
 * <td class='confluenceTd'>&nbsp;</td>
 * <td class='confluenceTd'>&nbsp;</td>
 * </tr>
 * <tr>
 * <td class='confluenceTd'>shortCircuit</td>
 * <td class='confluenceTd'>no</td>
 * <td class='confluenceTd'>false</td>
 * <td class='confluenceTd'>If this validator should be used as shortCircuit.</td>
 * </tr>
 * <tr>
 * <td class='confluenceTd'>type</td>
 * <td class='confluenceTd'>yes</td>
 * <td class='confluenceTd'>ValidatorType.FIELD</td>
 * <td class='confluenceTd'>Enum value from ValidatorType. Either FIELD or SIMPLE can be used here.</td>
 * </tr>
 * <tr>
 * <td class='confluenceTd'> expression </td>
 * <td class='confluenceTd'> yes </td>
 * <td class='confluenceTd'>&nbsp;</td>
 * <td class='confluenceTd'> An OGNL expression that returns a boolean value.  </td>
 * </tr>
 * </table>
 * <!-- END SNIPPET: parameters -->
 *
 * <p/> <u>Example code:</u>
 *
 * <pre>
 * <!-- START SNIPPET: example -->
 * &#64;FieldExpressionValidator(message = "Default message", key = "i18n.key", shortCircuit = true, expression = "an OGNL expression")
 * <!-- END SNIPPET: example -->
 * </pre>
 *
 * @author Rainer Hermanns
 * @version $Id: FieldExpressionValidator.java 1187 2006-11-13 08:05:32Z mrdon $
 */
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface FieldExpressionValidator {

    /**
     *  An OGNL expression that returns a boolean value.
     */
    String expression();

    /**
     * The default error message for this validator.
     */
    String message();

    /**
     * The message key to lookup for i18n.
     */
    String key() default "";

    /**
     * The optional fieldName for SIMPLE validator types.
     */
    String fieldName() default "";

    /**
     * If this is activated, the validator will be used as short-circuit.
     *
     * Adds the short-circuit="true" attribute value if <tt>true</tt>.
     *
     */
    boolean shortCircuit() default false;
}