Thinker IN JAVA - BlogJava

1.?如何使用导出功能

Q: 如何使用导出功能

A: 为了使用导出功能，只需要在web.xml文件中加入eXtremeComponents的导出过滤器的配置，内容如下：

<filter>
    <filter-name>eXtremeExport</filter-name>
    <filter-class>org.extremecomponents.table.filter.ExportFilter</filter-class>
    <init-param>
      <param-name>responseHeadersSetBeforeDoFilter</param-name>
      <param-value>true</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>eXtremeExport</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

2.?传入中文参数乱码

Q: 传入中文参数乱码，如下页面：

		<form id="form1" name="form1" method="post" action="应用eXtremeTable的action或是结果页面名">
  <select name="selecttype" size="6">
    <option value="第一个">第一个</option>
    <option value="第二个">第二个</option>
    <option value="第三个">第三个</option>
  </select>
  <input type="text" name="username" />
  <input type="submit" name="Submit" value="提交" />
</form>

当你提交时含有eXtremeTable的结果页面会自动取得页面上的表单参数，那怕是经过了action的mapping.findForward("forward"),在我的试用过程中到页面上会出现传递过去的参数，但出现了乱码问题，使用查询（filter）功能是的中文参数问题类似。

A:

确认服务器的参数是否设置了正确的编码，如果使用Tomcat请确认Server.xml：

 <Connector port="80" URIEncoding="UTF-8" maxThreads="150" minSpareThreads="25" maxSpareThreads="75" enableLookups="false"
            redirectPort="8443" acceptCount="100" debug="0" connectionTimeout="20000" disableUploadTimeout="true" />

添加编码过滤器到你的应用工程：

/*
 * Copyright 1999-2001,2004 The Apache Software Foundation.
 *
 * 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 filters;


import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.UnavailableException;


/**
 * <p>Example filter that sets the character encoding to be used in parsing the
 * incoming request, either unconditionally or only if the client did not
 * specify a character encoding.  Configuration of this filter is based on
 * the following initialization parameters:</p>
 * <ul>
 * <li><strong>encoding</strong> - The character encoding to be configured
 *     for this request, either conditionally or unconditionally based on
 *     the <code>ignore</code> initialization parameter.  This parameter
 *     is required, so there is no default.</li>
 * <li><strong>ignore</strong> - If set to "true", any character encoding
 *     specified by the client is ignored, and the value returned by the
 *     <code>selectEncoding()</code> method is set.  If set to "false,
 *     <code>selectEncoding()</code> is called <strong>only</strong> if the
 *     client has not already specified an encoding.  By default, this
 *     parameter is set to "true".</li>
 * </ul>
 *
 * <p>Although this filter can be used unchanged, it is also easy to
 * subclass it and make the <code>selectEncoding()</code> method more
 * intelligent about what encoding to choose, based on characteristics of
 * the incoming request (such as the values of the <code>Accept-Language</code>
 * and <code>User-Agent</code> headers, or a value stashed in the current
 * user's session.</p>
 *
 * @author Craig McClanahan
 * @version $Revision: 1.3 $ $Date: 2004/02/28 03:35:22 $
 */

public class SetCharacterEncodingFilter implements Filter {


    // ----------------------------------------------------- Instance Variables


    /**
     * The default character encoding to set for requests that pass through
     * this filter.
     */
    protected String encoding = null;


    /**
     * The filter configuration object we are associated with.  If this value
     * is null, this filter instance is not currently configured.
     */
    protected FilterConfig filterConfig = null;


    /**
     * Should a character encoding specified by the client be ignored?
     */
    protected boolean ignore = true;


    // --------------------------------------------------------- Public Methods


    /**
     * Take this filter out of service.
     */
    public void destroy() {

        this.encoding = null;
        this.filterConfig = null;

    }


    /**
     * Select and set (if specified) the character encoding to be used to
     * interpret request parameters for this request.
     *
     * @param request The servlet request we are processing
     * @param result The servlet response we are creating
     * @param chain The filter chain we are processing
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet error occurs
     */
    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain)
   throws IOException, ServletException {

        // Conditionally select and set the character encoding to be used
        if (ignore || (request.getCharacterEncoding() == null)) {
            String encoding = selectEncoding(request);
            if (encoding != null)
                request.setCharacterEncoding(encoding);
        }

   // Pass control on to the next filter
        chain.doFilter(request, response);

    }


    /**
     * Place this filter into service.
     *
     * @param filterConfig The filter configuration object
     */
    public void init(FilterConfig filterConfig) throws ServletException {

   this.filterConfig = filterConfig;
        this.encoding = filterConfig.getInitParameter("encoding");
        String value = filterConfig.getInitParameter("ignore");
        if (value == null)
            this.ignore = true;
        else if (value.equalsIgnoreCase("true"))
            this.ignore = true;
        else if (value.equalsIgnoreCase("yes"))
            this.ignore = true;
        else
            this.ignore = false;

    }


    // ------------------------------------------------------ Protected Methods


    /**
     * Select an appropriate character encoding to be used, based on the
     * characteristics of the current request and/or filter initialization
     * parameters.  If no character encoding should be set, return
     * <code>null</code>.
     * <p>
     * The default implementation unconditionally returns the value configured
     * by the <strong>encoding</strong> initialization parameter for this
     * filter.
     *
     * @param request The servlet request we are processing
     */
    protected String selectEncoding(ServletRequest request) {

        return (this.encoding);

    }


}

在web.xml中添加编码过滤器配置：

 <filter>
    <filter-name>Set Character Encoding</filter-name>
    <filter-class>filters.SetCharacterEncodingFilter</filter-class>
    <init-param>
      <param-name>encoding</param-name>
      <param-value>gb2312</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>Set Character Encoding</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

3.?导出时中文文件名乱码

Q：关于导出时中文文件名为乱码的问题

A: 这是个bug，建议使用英文文件名，主要原因还是编码问题。我们现在正在想办法解决。

4.?导出时文件内容乱码

Q：导出时文件内容乱码

A:首先请确认使用的是extremecomponents-1.0.1-M5-A4版以后的版本

Excle：导出为Excle的中文问题已经修正，默认的情况下支持导出中文，用户不需要任何改动
PDF ：由于extremecomponents使用了FOP来生成PDF文件，FOP在导出中文内容时会产生乱码。具体的解决方案大家可以参考最新eXtremeComponents包：支持 PDF中文导出

5.?变量命名问题

Q：当变量名为"action"，在IE下执行产生javascript错误

A: 内部使用了一些关键字，就目前我所知的为"action"、"submit"。建议大家命名时尽量避免，如果大家必须使用，则可以使用table标签的autoIncludeParameters参数设置为"false":

autoIncludeParameters="false"

6.?格式化输出表单中的数据

Q：怎么样格式化输出表单中的数据

A: 你可以设置列的cell：

日期格式化： cell = " date " format = " yyyy-MM-dd "
数字格式化： cell="currency" format="###,###,##0.00"

详细信息请参考指南

7.?加入链接

Q：怎么样加入链接

A: 你可以参考下例:

            <ec:table
    var="pres"
    items="presidents"
    action="${pageContext.request.contextPath}/compact.run"
    imagePath="${pageContext.request.contextPath}/images/table/compact/*.gif"
    view="compact"
    title="Compact Toolbar View"
    showTooltips="false"
    >
      <ec:exportPdf
           fileName="output.pdf"
           tooltip="Export PDF"
           headerColor="black"
           headerBackgroundColor="#b6c2da"
           headerTitle="Presidents"
           text="PDF"
           />
      <ec:exportXls
           fileName="output.xls"
           tooltip="Export Excel"
           text="XLS"
           />
        <ec:row>
            <ec:column property="fullName" title="Name">
               <a href="http://www.whitehouse.gov/history/presidents/">${pres.fullName}</a>
            </ec:column>
            <ec:column property="nickName"/>
            <ec:column property="term"/>
            <ec:column property="born" cell="date"/>
            <ec:column property="died" cell="date"/>
            <ec:column property="career"/>
        </ec:row>
  </ec:table>