Struts example source code file (FieldError.java)

This example Struts source code file (FieldError.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Struts tags/keywords

boolean, fielderror, fielderror, http, list, override, render, request, response, servlet, string, string, strutstag, strutstagattribute, strutstagattribute, template, template, uibean, util

The Struts FieldError.java source code

/*
 * $Id: FieldError.java 805635 2009-08-19 00:18:54Z musachy $
 *
 * 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.struts2.components;

import com.opensymphony.xwork2.util.ValueStack;
import org.apache.struts2.components.Param.UnnamedParametric;
import org.apache.struts2.views.annotations.StrutsTag;
import org.apache.struts2.views.annotations.StrutsTagAttribute;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.ArrayList;
import java.util.List;

/**
 * <!-- START SNIPPET: javadoc -->
 *
 * Render field errors if they exists. Specific layout depends on the particular theme.
 * The field error strings will be html escaped by default.
 *
 * <!-- END SNIPPET: javadoc -->
 *
 * <p/> Examples
 *
 * <pre>
 * <!-- START SNIPPET: example -->
 *
 *    <!-- example 1 -->
 *    <s:fielderror />
 *
 *    <!-- example 2 -->
 *    <s:fielderror>
 *         <s:param>field1</s:param>
 *         <s:param>field2</s:param>
 *    </s:fielderror>
 *    <s:form .... >
 *       ....
 *    </s:form>
 *
 *    OR
 *
 *    <s:fielderror>
 *          <s:param value="%{'field1'}" />
 *          <s:param value="%{'field2'}" />
 *    </s:fielderror>
 *    <s:form .... >
 *       ....
 *    </s:form>
 *
 *    OR
 *
 *    <s:fielderror fieldName="field1" />
 *
 * <!-- END SNIPPET: example -->
 * </pre>
 *
 *
 * <p/> Description

 *
 *
 * <pre>
 * <!-- START SNIPPET: description -->
 *
 * Example 1: display all field errors<p/>
 * Example 2: display field errors only for 'field1' and 'field2'<p/>
 *
 * <!-- END SNIPPET: description -->
 * </pre>
 *
 */
@StrutsTag(name="fielderror", tldTagClass="org.apache.struts2.views.jsp.ui.FieldErrorTag", description="Render field error (all " +
                "or partial depending on param tag nested)if they exists")
public class FieldError extends UIBean implements UnnamedParametric {

    private List<String> errorFieldNames = new ArrayList();
    private boolean escape = true;

    public FieldError(ValueStack stack, HttpServletRequest request, HttpServletResponse response) {
        super(stack, request, response);
    }

    private static final String TEMPLATE = "fielderror";

    protected String getDefaultTemplate() {
        return TEMPLATE;
    }

    @Override
    protected void evaluateExtraParams() {
        super.evaluateExtraParams();

        if (errorFieldNames != null)
            addParameter("errorFieldNames", errorFieldNames);

        addParameter("escape", escape);
    }

    public void addParameter(Object value) {
        if (value != null) {
            errorFieldNames.add(value.toString());
        }
    }

    public List<String> getFieldErrorFieldNames() {
        return errorFieldNames;
    }

    @StrutsTagAttribute(description="Field name for single field attribute usage", type="String")
    public void setFieldName(String fieldName) {
        addParameter(fieldName);
    }

    @StrutsTagAttribute(description=" Whether to escape HTML", type="Boolean", defaultValue="true")
    public void setEscape(boolean escape) {
        this.escape = escape;
    }
}