createviewpage.java

Java/J2EE框架Jdon-Framework系统的Sample

/**
 * Copyright 2005 Jdon.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.jdon.strutsutil.util;

import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionForm;
import javax.servlet.http.HttpServletRequest;

import com.jdon.util.Debug;

import com.jdon.model.ModelHandler;
import com.jdon.model.ModelForm;
import com.jdon.model.ModelManager;
import com.jdon.strutsutil.FormBeanUtil;
import org.apache.struts.config.FormBeanConfig;
import org.apache.struts.config.ModuleConfig;


/**
 *  提供用于Model创建页面的准备工作
 * <p>Copyright: Jdon.com Copyright (c) 2003</p>
 * <p></p>
 * @author banq
 * @version 1.0
 */
public class CreateViewPage {
  private final static String module = CreateViewPage.class.getName();

  private ModelManager modelManager;
  public CreateViewPage(ModelManager modelManager) {
    this.modelManager = modelManager;
  }

  /**
   * 如果在action配置中，配置了name值，那么直接使用Struts自动生成的ModelForm实例
   * 如果只规定了attribute值，那么使用ModelHandler子类initForm的ModelForm实例
   * @param actionMapping ActionMapping
   * @param actionForm ActionForm
   * @param request HttpServletRequest
   * @throws Exception
   */
  public void doCreate(ActionMapping actionMapping,
                       ActionForm actionForm,
                       HttpServletRequest request,
                       ModuleConfig moduleConfig) throws Exception {
    Debug.logVerbose(" enter doCreate... ", module);
    ModelForm form = getModelFormFromHandler(actionMapping, actionForm, request);
    if (form == null)
      if (actionForm != null)
        form = (ModelForm) actionForm;
      else
        form = FormBeanUtil.createModelFormNow(actionMapping, actionForm, request,
                                               moduleConfig);
    form.setAction(ModelForm.CREATE_STR);
  }

  /**
   * 为创家页面准备一个ModelForm实例
   * @param actionMapping
   * @param request
   * @return
   * @throws java.lang.Exception
   */
  private ModelForm getModelFormFromHandler(ActionMapping actionMapping,
                                          ActionForm actionForm,
                                          HttpServletRequest request) throws
      Exception {
    String formName = FormBeanUtil.getFormName(actionMapping);
    ModelHandler modelHandler = modelManager.borrowtHandlerObject(formName);
    ModelForm form = null;
    try {
      form = modelHandler.initForm(request);
      Debug.logVerbose(" active modelHandler.initForm ", module);
      FormBeanUtil.saveActionForm(form, actionMapping, request);
      if (modelHandler != null)
          modelHandler.customizeForm(form, request);
    } catch (Exception ex) {
      Debug.logError("please check struts-config.xml or modelHandler.initForm" +
                     ex, module);
      throw new Exception("System error! please call system Admin." + ex);
    } finally {
      modelManager.returnHandlerObject(modelHandler); //返回modelhandler再用
    }
    return form;
  }




}