struts2+poi导出excel出错

Question

做struts2+poi导出excel时，发生如下错误，不知怎么解决，请各位指教：

java.lang.IllegalStateException: Cannot call sendError() after the response has been committed
	at org.apache.catalina.connector.ResponseFacade.sendError(ResponseFacade.java:462)
	at org.apache.struts2.dispatcher.DefaultDispatcherErrorHandler.sendErrorResponse(DefaultDispatcherErrorHandler.java:80)
	at org.apache.struts2.dispatcher.DefaultDispatcherErrorHandler.handleError(DefaultDispatcherErrorHandler.java:59)
	at org.apache.struts2.dispatcher.Dispatcher.sendError(Dispatcher.java:909)
	at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:576)
	at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:81)
	at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:537)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1085)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:658)
	at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1556)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1513)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:745)

struts.xml文件

<!-- 导出excel -->
		<action name="export_*" class="org.fkjava.s2sh.action.ExportExcelAction">
			<result name="success" type="stream">
				<!-- 指定二进制流的类型 -->
				<param name="contentType">${fileType}</param>
				<!-- 默认就是 inputStream，它将会指示 StreamResult 通过 inputName 属性值的 getter 方法, 
					比如这里就是 getExcelInputStream() 来获取下载文件的内容，意味着你的 Action 要有这个方法 
				-->
				<param name="inputName">is</param>
				<param name="contentDisposition"> attachment;filename=${fileName}</param> 
				<!-- 输出时缓冲区的大小 -->
				<param name="bufferSize">4096</param>
			</result>
		</action>

action

package org.fkjava.s2sh.action;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.List;

import org.fkjava.s2sh.domain.User;
import org.fkjava.s2sh.service.UserService;
import org.fkjava.s2sh.util.ExcelUtil;

import com.opensymphony.xwork2.Action;

public class ExportExcelAction implements Action {
	private UserService us;
	private List<User> users;
	private String fileType;
	private String fileName;

	public String getFileName() {
		return fileName;
	}

	public void setFileName(String fileName) {
		this.fileName = fileName;
	}

	public String getFileType() {
		return fileType;
	}

	public void setFileType(String fileType) {
		this.fileType = fileType;
	}

	public List<User> getUsers() {
		return users;
	}

	public void setUsres(List<User> users) {
		this.users = users;
	}

	public void setUs(UserService us) {
		this.us = us;
	}

	public InputStream getIs() {
		users = us.getAllUser(null);
		ByteArrayOutputStream out = null;
		if (fileType.equals("application/vnd.ms-excel")) {
			out = new ByteArrayOutputStream();
			ExcelUtil.toExcel(users, out);
			return new ByteArrayInputStream(out.toByteArray());
		}
		return null;
	}

	@Override
	public String execute() throws Exception {
		return SUCCESS;
	}
}

jsp页面

<a href="${pageContext.request.contextPath }/export_excel?fileType=application/vnd.ms-excel&fileName=userInfo.xls">导出Excel报表</a>

ExcelUtil.java

package org.fkjava.s2sh.util;

import java.io.OutputStream;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFDataFormat;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.fkjava.s2sh.domain.User;

/**
 * excel导出工具类
 * 
 * @author 杨仔
 * @Description TODO
 * @ClassName ExcelUtil
 * @date 2015年10月10日
 * @version 1.0
 *
 */
public class ExcelUtil {
	public static void toExcel(List<User> users, OutputStream out) {

		String[] title = { "姓名", "密码", "生日" };

		try {
			HSSFWorkbook wwb = new HSSFWorkbook();

			// 创建工作簿
			HSSFSheet sheet = wwb.createSheet("教学档案");

			HSSFRow row = null;
			// 创建表头
			row = sheet.createRow(0);
			for (int i = 0; i < title.length; i++) {
				row.createCell(i).setCellValue(title[i]);
			}

			// 添加内容
			User user = null;
			for (int i = 0; i < users.size(); i++) {
				user = users.get(i);

				row = sheet.createRow(i + 1);

				// 列
				row.createCell(0).setCellValue(user.getName());
				row.createCell(1).setCellValue(user.getPass());
				row.createCell(2).setCellValue(user.getBirth());

			}

			HSSFDataFormat format = wwb.createDataFormat();
			// 格式化数据
			HSSFCellStyle style = wwb.createCellStyle();
			style.setDataFormat(format.getFormat("yyyy-MM-dd hh
              

Answer 1

getIs方法响应了两次，就报这个错，不知怎么解决

Answer 2

就是你说的struts响应OutputStream这部分，但我不知道怎么改

Answer 3

回复
struts了解不是很深，帮不到你了。 两次响应这种问题应该是常见问题吧？

Answer 4

就是不知道怎么解决这种两次响应问题

Answer 5

回复
http://bbs.csdn.net/topics/370053062，借鉴一下吧。

Answer 6

谢谢啊

Answer 7

表面上看是 response 时，出现问题了

java.lang.IllegalStateException: Cannot call sendError() after the response has been committed

深层次的问题需要确定你

ExcelUtil.toExcel(users, out);

方法是否正确工作了，如果这句话正确并且产生的 excel 没问题。那么重点就落在你  struts 响应 OutputStream 这部分吧。

Answer 8

刚开始把contentType在struts.xml中写死是可以的，我后来改成$(fileType)就报错了了，

Answer 9

jsp页面问题，导出excel要用把参数以form的形式提交。