目前需求, 客户上传excel文件, 有列名, 列名不固定, 想预览数据, 使用Jmesa做table, 有两种实现方法. 第一种使用动态类, 封装map对象. 第二种是一种巧妙的方法. 下面先介绍第一种方法:
使用动态类:
package com.founder.cst.action;
import Java.util.ArrayList;
import Java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.beanutils.BasicDynaBean;
import org.apache.commons.beanutils.BasicDynaClass;
import org.apache.commons.beanutils.DynaBean;
import org.apache.commons.beanutils.DynaClass;
import org.apache.commons.beanutils.DynaProperty;
import org.jmesa.core.filter.MatcherKey;
import org.jmesa.facade.TableFacade;
import org.jmesa.facade.TableFacadeFactory;
import org.jmesa.view.html.component.HtmlTable;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import com.founder.cst.common.StringFilterMatcher;
@Controller
@RequestMapping
public class DynaController {
@RequestMapping
public String books(final HttpServletRequest request, HttpServletResponse response, ModelMap model){
DynaClass bookClass = createBasicDynaClass();
try {
List<DynaBean> results = new ArrayList<DynaBean>();
DynaBean book11 = bookClass.newInstance();
book11.set("id", "1");
book11.set("name", "Spring");
book11.set("price", "18.29");
results.add(book11);
DynaBean book22 = bookClass.newInstance();
book22.set("id", "2");
book22.set("name", "Hibernate");
book22.set("price", "12.29");
results.add(book22);
DynaBean book33 = bookClass.newInstance();
book33.set("id", "3");
book33.set("name", "Python");
book33.set("price", "17.32");
results.add(book33);
TableFacade tableFacade = TableFacadeFactory.createTableFacade("booksTable", request);
tableFacade.setColumnProperties("id", "name", "price");
tableFacade.setMaxRows(10);
tableFacade.setMaxRowsIncrements(10, 20, 30);
tableFacade.setItems(results);
HtmlTable table = (HtmlTable) tableFacade.getTable();
table.getTableRenderer().setWidth("558px");
table.getRow().setUniqueProperty("id");
String html = tableFacade.render();
model.addAttribute("html", html);
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return "books";
}
public DynaClass createBasicDynaClass() {
DynaClass dynaClass = null;
//create basic field for dynaClass
DynaProperty[] dynaProps = new DynaProperty[3];
dynaProps[0] = new DynaProperty("id");
dynaProps[1] = new DynaProperty("name", String.class);
dynaProps[2] = new DynaProperty("price", String.class);
//create map filed for dynaClass
dynaClass = new BasicDynaClass("first", BasicDynaBean.class, dynaProps);
return dynaClass;
}
}
下面第二种:
@RequestMapping
public String bookslist(final HttpServletRequest request, HttpServletResponse response, ModelMap model){
List<Map<String, String>> books = new ArrayList<Map<String, String>>();
Map<String, String> book1 = new HashMap<String, String>();
book1.put("id", "1");
book1.put("name", "Spring");
book1.put("price", "18.29");
books.add(book1);
Map<String, String> book2 = new HashMap<String, String>();
book2.put("id", "2");
book2.put("name", "Hibernate");
book2.put("price", "28.98");
books.add(book2);
Map<String, String> book3 = new HashMap<String, String>();
book3.put("id", "3");
book3.put("name", "Python");
book3.put("price", "38.22");
books.add(book3);
model.addAttribute("books", books);
return "booklist";
}
<jmesa:tableFacade
id="booksTable"
items="${books}"
maxRows="10"
maxRowsIncrements="10,20,30"
var="book">
<jmesa:htmlTable width="630px">
<jmesa:htmlRow>
<c:forEach items="${book}" var="b">
<jmesa:htmlColumn property=" ${b.key}" title="${b.key}" filterable="false"/>
</c:forEach>
</jmesa:htmlRow>
</jmesa:htmlTable>
</jmesa:tableFacade>
这里注意property中的值.
今天查看源码, 和昨天想象一样, jmesa在渲染单元格的时候, 分两种, 一种就是map类型, 使用get(key)来取值, 另一种就是普通的javabean对象, 使用getPropertyName()取值渲染.
/*
* Copyright 2004 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 org.jmesa.util;
import Java.util.Collection;
import Java.util.Map;
import org.apache.commons.beanutils.PropertyUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* General utilities to process the Collecton of Beans or the Collection of
* Maps. Most methods wrap or add value to the commons Beanutils.
*
* @since 2.1
* @author Jeff Johnston
*/
public class ItemUtils {
private static final Logger logger = LoggerFactory.getLogger(ItemUtils.class);
public static final String JMESA_ITEM = "jmesa-item";
private ItemUtils() {
// hide constructor
}
/**
* Get the value from the Bean or Map by property.
*
* @param item The Bean or Map.
* @param property The Bean attribute or Map key.
* @return The value from the Bean or Map.
*/
public static Object getItemValue(Object item, String property) {
Object itemValue = null;
try {
if (item instanceof Map) {
itemValue = ((Map<?, ?>) item).get(property);
if (itemValue != null) {
return itemValue;
}
// ports such as the tags will store the original bean
Object bean = ((Map<?, ?>) item).get(JMESA_ITEM); if (bean == null) {
logger.debug("the map does not have property " + property);
return null;
}
itemValue = getItemValue(bean, property);
} else {
itemValue = PropertyUtils.getProperty(item, property);
}
} catch (Exception e) {
logger.debug("item class " + item.getClass().getName() + " does not have property " + property);
}
return itemValue;
}
/**
* Get the Class for the property.
*
* @param items The Collection of Beans or Maps.
* @param property The Bean attribute or Map key.
* @return The Class for the property.
*/
public static Class<?> getPropertyClassType(Collection<?> items, String property)
throws Exception {
Object item = items.iterator().next();
if (item instanceof Map) {
for (Object object : items) {
Map map = (Map) object;
Object val = map.get(property);
if (val == null) {
continue;
}
return val.getClass();
}
}
return PropertyUtils.getPropertyType(item, property);
}
}