Java的Excel导出功能

<servlet>
<description>
</description>
<display-name>ExcelServlet</display-name>
<servlet-name>ExcelServlet</servlet-name>
<servlet-class>
*.excel.ExcelServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ExcelServlet</servlet-name>
<url-pattern>*.xls</url-pattern>
</servlet-mapping>

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.log4j.Logger;
public class ExcelServlet extends HttpServlet {
private final Logger log = Log4jUtil.getLogger(ExcelServlet.class);
public void init() throws ServletException {
}
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("application/vnd.ms-excel");
RequestPage page = new RequestPage(request, response, request.getSession());
ExcelOperator operator = null;
try {
operator = getOperator(request.getServletPath());
if (operator != null) {
operator.execute(page);
}
} catch (Exception ex) {
log.debug("导出excel出错：" + ex.toString());
ex.printStackTrace();
}
}
/**
* 根据不同的请求path获取不同的导出excel操作
*
* @param path
* @return
*/
public ExcelOperator getOperator(String path) {
return new ReportExcelExport();

}

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
public void destroy() {
}
}

import java.io.IOException;
import jxl.write.WriteException;

public abstract class ExcelOperator {

jxl.write.WritableWorkbook excel = null;
int fieldCount = 0;
public RequestPage page;
public void execute(RequestPage page) throws WriteException,
IndexOutOfBoundsException, IOException {
this.page = page;
excel = jxl.Workbook.createWorkbook(this.page.getResponse()
.getOutputStream());
excel.createSheet("sheet1", 0);
setTitle(getTitle());
writeContent(getContent());
write();
}
private void setTitle(String[] fields) throws IndexOutOfBoundsException,
WriteException {
this.fieldCount = fields.length;
for (int i = 0; i < fields.length; i++) {
excel.getSheet(0).addCell(new jxl.write.Label(i, 0, fields[i]));
}
}
private void writeContent(java.util.ArrayList cells)
throws IndexOutOfBoundsException, WriteException {
if (cells == null)
return;
for (int i = 1; i <= cells.size(); i++) {
Object obj = cells.get(i - 1);
for (int j = 0; j < fieldCount; j++) {
excel.getSheet(0).addCell(
new jxl.write.Label(j, i, getValue(obj, j)));
}
}
}
public abstract String getValue(Object obj, int index);
public abstract String[] getTitle();
public abstract java.util.ArrayList getContent();
private void write() throws IOException, WriteException, IOException {
excel.write();
excel.close();
}
}

import java.util.ArrayList;
import java.util.HashMap;
public class ReportExcelExport extends ExcelOperator {
@Override
public ArrayList getContent() {
}
/**
* 报表表头
*/
@Override
public String[] getTitle() {
return new String[] { "责任人ID","责任人","责任人角色","年份" };
}
/**
* 单元格的值
*/
@Override
public String getValue(Object obj, int index) {
switch (index) {
case 0:
return values.getUserId();

default:
return "";
}
}
}

if (request.getHeader("User-Agent").indexOf("MSIE 5.5") != -1) {
response.setHeader("Content-Disposition", "filename=" + fileName);
} else {
response.addHeader("Content-Disposition", "attachment;filename=" + fileName);
}
response.setCharacterEncoding("GBK");
//response.setContentType("text/html;charset=GBK");
ServletOutputStream stream = null;
BufferedInputStream buf = null;
FileInputStream fis = null;
try {
stream = response.getOutputStream();
fis = new FileInputStream(file);
buf = new BufferedInputStream(fis);
byte[] readBytes = new byte[4096];
int len = 0;
while ((len = buf.read(readBytes)) != -1) {
stream.write(readBytes, 0, len);
}
stream.flush();
response.setStatus(HttpServletResponse.SC_OK);
response.flushBuffer();
} catch (Exception ex) {
logger.info(ex.toString());
} finally {
if (stream != null) {
try {
stream.close();
} catch (IOException e) {
logger.info(e.toString());
e.printStackTrace();
}
}
if (buf != null) {
try {
buf.close();
} catch (IOException e) {
logger.info(e.toString());
e.printStackTrace();
}
}
if (fis != null) {
try {
fis.close();
} catch (IOException e) {
logger.info(e.toString());
e.printStackTrace();
}
}
}