editeviewpageutil.java

用jbuilder写的源程序

/**
 * Copyright 2003-2006 the original author or authors.
 * 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 javax.servlet.http.HttpServletRequest;

import org.apache.commons.beanutils.ConvertUtils;
import org.apache.struts.action.ActionMapping;

import com.jdon.controller.model.ModelIF;
import com.jdon.model.ModelForm;
import com.jdon.model.ModelHandler;
import com.jdon.model.ModelKey;
import com.jdon.model.ModelManager;
import com.jdon.model.config.ModelMapping;
import com.jdon.strutsutil.FormBeanUtil;
import com.jdon.util.Debug;

/**
 * prepare for push a editable jsp page. this class will call the service to get
 * a model that has datas. this work will delegate the ModelHandler class
 * 
 * 
 * @author banq
 */
public class EditeViewPageUtil {
    private final static String module = EditeViewPageUtil.class.getName();

    protected ModelManager modelManager;


    public EditeViewPageUtil(ModelManager modelManager) {
        this.modelManager = modelManager;
    }

    /**
     * two things: 1. create a ModelForm null instance 2. obtain a existed Model
     * instance copy the Model instance to the ModelForm instance
     *  
     */
    public ModelIF getModelForEdit(ActionMapping actionMapping, ModelForm modelForm, HttpServletRequest request)
            throws Exception {
        ModelIF model = null;
        ModelHandler modelHandler = null;
        try {
            String formName = FormBeanUtil.getFormName(actionMapping);
            modelHandler = modelManager.borrowtHandlerObject(formName);

            ModelForm form = modelHandler.initForm(request);
            if (form != null) {
                form.setAction(ModelForm.EDIT_STR);
                FormBeanUtil.saveActionForm(form, actionMapping, request);
            } else {
                form = modelForm;
            }
            Debug.logVerbose("[JdonFramework] got a ModelForm ... ", module);

            Debug.logVerbose("[JdonFramework] prepare to fetch a Model from service layer", module);
            model = fetchModel(request, formName, modelHandler);
            Debug.logVerbose("[JdonFramework] got the Model data successfully..", module);

            modelHandler.modelIFCopyToForm(model, form);

        } catch (Exception ex) {
            Debug.logError("[JdonFramework]please check your service 、 model or form, error is: " + ex, module);
        } finally {
            modelManager.returnHandlerObject(modelHandler); //返回modelhandler再用
        }
        return model;
    }

    protected ModelIF fetchModel(HttpServletRequest request, String formName, ModelHandler modelHandler) throws Exception {
        ModelIF model = null;
        try {
            Object keyValue = getParamKeyValue(request, modelHandler);
            clearModelCache(formName, keyValue, modelHandler);
            model = modelHandler.findModelIF(keyValue, request);
            if (model == null) {
                Debug.logError("[JdonFramework] Error: got a NULL Model..", module);
                throw new Exception("got a NULL Model");
            } else {
                addModelCache(formName, keyValue, modelHandler, model);
            }
        } catch (Exception ex) {
            Debug.logError("[JdonFramework] the method 'findModelByKey' of your handler or 'getMethod' of service happened error: " + ex, module);
            throw new Exception(ex);
        }
        return model;
    }
    
   
    private void clearModelCache(String formName, Object keyValue, ModelHandler modelHandler) {
        ModelIF model = null;
        try {
            ModelKey modelKey = new ModelKey(keyValue, formName);
            model = modelManager.getCache(modelKey);
            if (model != null) {//clear the cache
                modelManager.removeCache(keyValue);
            }
        } catch (Exception e) {
            Debug.logError("[JdonFramework] clearModelCache error: " + e);
        }
    }

    private void addModelCache(String formName, Object keyValue, ModelHandler modelHandler, ModelIF model) {
        ModelKey modelKey = new ModelKey(keyValue, formName);
        modelManager.addCache(modelKey, model);
    }

    /**
     * 获得参数key值 例如： /admin/productAction.do?action=edit&productId=1721
     * 缺省:productId为product的modelmapping.xml中key定义值
     * 
     * 对于如下调用： /admin/productAction.do?action=edit&userId=16
     * userId不是modelmapping.xml中key定义值，则需要override本方法，
     * 
     * 
     * @param actionMapping
     * @param request
     * @return 参数key值
     * @throws java.lang.Exception
     */
    public Object getParamKeyValue(HttpServletRequest request, ModelHandler modelHandler) {

        Object keyValue = null;
		try {
			ModelMapping modelMapping = modelHandler.getModelMapping();
			String keyName = modelMapping.getKeyName();
			Debug.logVerbose("[JdonFramework] the keyName is  " + keyName, module);
			String keyValueS = request.getParameter(keyName);
			Debug.logVerbose("[JdonFramework] got the keyValue is  " + keyValueS, module);
			if (keyValueS == null) {
			    Debug.logVerbose("[JdonFramework]the keyValue is null", module);
			}
			Class keyClassType = modelMapping.getKeyClassType();
			if (keyClassType.isAssignableFrom(String.class)) {
				keyValue = keyValueS;
			}else{
				Debug.logVerbose("[JdonFramework] convert String keyValue to" + keyClassType.getName(), module);
				keyValue = ConvertUtils.convert(keyValueS, keyClassType);
			}
		} catch (Exception e) {
			Debug.logError("[JdonFramework] getParamKeyValue error: " + e);
		}
        return keyValue;
    }

}