java excel 文件导出
excel文件导出有两种，一种是以io流直接生成，一种是在本地生成一个excel文件（fileoutputStream)。这两种相比较而言应该是直接以io流直接生成更方便点。具体的生成方式如下：
1.在本地生成文件
a.新建一个Student实体,具体如下
package excel;
import java.util.Date;
public class Student {
private int id;
private String name;
private int age;
private Date birth;
public Student() {
}
public Student(int id, String name, int age, Date birth) {
this.id = id;
this.name = name;
this.age = age;
this.birth = birth;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public Date getBirth() {
return birth;
}
public void setBirth(Date birth) {
this.birth = birth;
}
}
b.生成file文件的实现如下：
package excel;import java.io.FileOutputStream; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.List; import org.apache.poi.hssf.usermodel.HSSFCell; import org.apache.poi.hssf.usermodel.HSSFCellStyle; import org.apache.poi.hssf.usermodel.HSSFRow; import org.apache.poi.hssf.usermodel.HSSFSheet; import org.apache.poi.hssf.usermodel.HSSFWorkbook; public class Test { /** * @功能：手工构建一个简单格式的Excel */ private static ListgetStudent() throws Exception
{
List list = new ArrayList();
SimpleDateFormat df = new SimpleDateFormat("yyyy-mm-dd");
Student user1 = new Student(1, "张三", 16, df.parse("1997-03-12"));
Student user2 = new Student(2, "李四", 17, df.parse("1996-08-12"));
Student user3 = new Student(3, "王五", 26, df.parse("1985-11-12"));
list.add(user1);
list.add(user2);
list.add(user3);
return list;
}
public static void main(String[] args) throws Exception
{
// 第一步，创建一个webbook，对应一个Excel文件
HSSFWorkbook wb = new HSSFWorkbook();
// 第二步，在webbook中添加一个sheet,对应Excel文件中的sheet
HSSFSheet sheet = wb.createSheet("学生表一");
// 第三步，在sheet中添加表头第0行,注意老版本poi对Excel的行数列数有限制short
HSSFRow row = sheet.createRow((int) 0);
// 第四步，创建单元格，并设置值表头 设置表头居中
HSSFCellStyle style = wb.createCellStyle();
style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 创建一个居中格式
HSSFCell cell = row.createCell((short) 0);
cell.setCellValue("学号");
cell.setCellStyle(style);
cell = row.createCell((short) 1);
cell.setCellValue("姓名");
cell.setCellStyle(style);
cell = row.createCell((short) 2);
cell.setCellValue("年龄");
cell.setCellStyle(style);
cell = row.createCell((short) 3);
cell.setCellValue("生日");
cell.setCellStyle(style);
// 第五步，写入实体数据 实际应用中这些数据从数据库得到，
List list = Test.getStudent();
for (int i = 0; i < list.size(); i++)
{
row = sheet.createRow((int) i + 1);
Student stu = (Student) list.get(i);
// 第四步，创建单元格，并设置值
row.createCell((short) 0).setCellValue((double) stu.getId());
row.createCell((short) 1).setCellValue(stu.getName());
row.createCell((short) 2).setCellValue((double) stu.getAge());
cell = row.createCell((short) 3);
cell.setCellValue(new SimpleDateFormat("yyyy-mm-dd").format(stu
.getBirth()));
}
// 第六步，将文件存到指定位置
try
{
FileOutputStream fout = new FileOutputStream("E:/students.xls");
wb.write(fout);
fout.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
2.生成io流的实现如下：
package excel;import java.io.IOException;import java.io.OutputStream;import java.net.URLEncoder;import java.util.List;import javax.servlet.http.HttpServletResponse;import org.apache.poi.hssf.usermodel.HSSFRow;import org.apache.poi.hssf.usermodel.HSSFSheet;import org.apache.poi.hssf.usermodel.HSSFWorkbook;public class TestB {/** * 导出到Excel * * @param list * @param response */public void exportToExcel(Listlist, HttpServletResponse response) {OutputStream os = null;HSSFWorkbook hw = null;try {String fileName = "学生表.xlsx";os = response.getOutputStream();// 去除缓存response.reset();response.setHeader("Content-disposition", "attachment; filename = " + URLEncoder.encode(fileName, "UTF-8"));response.setContentType("application/octet-streem");hw = new HSSFWorkbook();// sheet名称HSSFSheet sheet = hw.createSheet("学生表");setSheetHeader(sheet);setSheetBody(sheet, list);hw.write(os);} catch (IOException e) {e.printStackTrace();} finally {if (null != os) {try {os.close();} catch (IOException e) {e.printStackTrace();}}}}/** * 头信息 * * @param hSheet */private void setSheetHeader(HSSFSheet hSheet) {HSSFRow hRow = hSheet.createRow(0);// 序号hRow.createCell(0).setCellValue("序号");hRow.createCell(1).setCellValue("姓名");hRow.createCell(2).setCellValue("电话");hRow.createCell(3).setCellValue("年龄");hRow.createCell(4).setCellValue("地址");}/** * 具体要导出的 内容 * @param list * @param hSheet */private void setSheetBody(HSSFSheet hSheet, Listlist) {
for (int i = 0; i < list.size(); i++) {
Student student = list.get(i);
HSSFRow row = hSheet.createRow(i + 1);
row.createCell(0).setCellValue(student.getId());
row.createCell(1).setCellValue(student.getBirth());
row.createCell(2).setCellValue(student.getName());
}
}
}
