关于SSH的一个特别小的例子

package com.test.service.impl; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.List; import org.apache.poi.hssf.usermodel.HSSFCell; import org.apache.poi.hssf.usermodel.HSSFRow; import org.apache.poi.hssf.usermodel.HSSFSheet; import org.apache.poi.hssf.usermodel.HSSFWorkbook; import com.test.bean.User; import com.test.dao.UserDAO; import com.test.service.UserService; import com.test.util.CharacterUtils; public class UserServiceImpl implements UserService { private UserDAO userDao; public UserDAO getUserDao() { return userDao; } public void setUserDao(UserDAO userDao) { this.userDao = userDao; } public void delete(User user) { this.userDao.removeUser(user); } public List<User> findAll() { return this.userDao.findAllUserss(); } public User findById(Integer id) { return this.userDao.findUserById(id); } public void save(User user) { this.userDao.saveUser(user); } public void update(User user) { this.userDao.updateUser(user); } public InputStream getInputStream(){ //生成HSSFWorkbook,相当于一个建立一个excel HSSFWorkbook wb = new HSSFWorkbook(); //由wb来创建一个sheet HSSFSheet sheet = wb.createSheet(); //由sheet创建一行 HSSFRow row = sheet.createRow(0); //在一行中建立一个单位格 HSSFCell cell = row.createCell((short)0); //设置单位格的编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); //设置单位格的内容 cell.setCellValue("序号"); cell = row.createCell((short)1); //设置单位格的编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); //设置单位格的内容 cell.setCellValue("姓"); cell = row.createCell((short)2); //设置单位格的编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); //设置单位格的内容 cell.setCellValue("名"); cell = row.createCell((short)3); //设置单位格的编码格式 cell.setEncoding(HSSFCell.ENCODING_UTF_16); //设置单位格的内容 cell.setCellValue("年龄"); List<User> list = this.findAll(); for(int i = 0; i < list.size(); i++){ User user = list.get(i); row = sheet.createRow(i+1); cell = row.createCell((short)0); cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(i+1); cell = row.createCell((short)1); cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(user.getFirstname()); cell = row.createCell((short)2); cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(user.getLastname()); //row = sheet.createRow(i+1); cell = row.createCell((short)3); cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(user.getAge()); } //输出流，并没有写到文件中，而是以byte的形式让在内存中，然后直接用输入流去读这些内容 ByteArrayOutputStream os = new ByteArrayOutputStream(); try{ wb.write(os); }catch(IOException e){ e.printStackTrace(); } byte[] content = os.toByteArray(); InputStream is = new ByteArrayInputStream(content); return is; /* byte[] content = wb.getBytes(); InputStream is = new ByteArrayInputStream(content); return is;*/ /*String filename = CharacterUtils.getRandomString(5); filename = new StringBuffer(filename).append(".xls").toString(); final File file = new File(filename); //引入输出流，文件流 //输出流：以电脑为中心，把东西输到文件中，为输出流 //输入流：把文件里的东西输入到电脑就为输入流 try { OutputStream os = new FileOutputStream(file); wb.write(os); os.close(); } catch (Exception e) { e.printStackTrace(); } InputStream is = null; try { is = new FileInputStream(file); } catch (Exception e) { e.printStackTrace(); } new Thread(new Runnable(){ public void run(){ try{ Thread.sleep(15000); }catch(InterruptedException e){ e.printStackTrace(); } file.delete();//删除文件 } }).start(); return is;*/ } }