Java POI导出Excel

Java POI导出Excel

JavaScript 脚本

<script type="text/javascript">
   function exportExcel(){
    var d = document.forms[0];
    d.action = "excelAction.action";
    d.submit;
  }
</script>

Jsp页面

<form action="">
      <input type="image" src="images/export.png" onclick="exportExcel()" />
</form>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="WebApp_ID" version="2.5">
<display-name>javapoi</display-name>
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>

<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>

Action 类

package com.zhanggaosong.poi;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
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;

import com.opensymphony.xwork2.ActionSupport;
import com.zhanggaosong.poi.domain.Student;

public class ExcelDownloadAction extends ActionSupport {

private static final long serialVersionUID = 1L;

/**
* @功能：手工构建一个简单格式的Excel
*/
private static List<Student> getStudent() throws Exception {
List<Student> list = new ArrayList<Student>();
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"));
Student user4 = new Student(4, "周六", 26, df.parse("1985-11-12"));
Student user5 = new Student(5, "赵七", 26, df.parse("1985-11-12"));
Student user6 = new Student(6, "关羽", 26, df.parse("1985-11-12"));

list.add(user1);
list.add(user2);
list.add(user3);
list.add(user4);
list.add(user5);
list.add(user6);

return list;
}

public InputStream getExcelFile() {

// 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("学生信息表");

// 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(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(0);

cell.setCellValue("学号");
cell.setCellStyle(style);
cell = row.createCell(1);
cell.setCellValue("姓名");
cell.setCellStyle(style);
cell = row.createCell(2);
cell.setCellValue("年龄");
cell.setCellStyle(style);
cell = row.createCell(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<Student> list = null;
try {
list = ExcelDownloadAction.getStudent();
} catch (Exception e1) {
e1.printStackTrace();
}
for (int i = 0; i < list.size(); i++) {

//设置自适应宽度 中文列无效
// sheet.autoSizeColumn(i+1);
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(0).setCellValue(stu.getId());
row.createCell(1).setCellValue(stu.getName());
row.createCell(2).setCellValue(stu.getAge());
row.createCell(3).setCellValue(new SimpleDateFormat("yyyy-mm-dd").format(stu.getBirth()));
}

ByteArrayOutputStream baos = new ByteArrayOutputStream();
try {
wb.write(baos);
} catch (IOException e) {
e.printStackTrace();
}
byte[] ba = baos.toByteArray();
ByteArrayInputStream bais = new ByteArrayInputStream(ba);
return bais;
}

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

Strudent实体

package com.zhanggaosong.poi.domain;
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;
}

}

Struts 2 配置文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
"http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>

<constant name="struts.enable.DynamicMethodInvocation" value="false" />
<constant name="struts.devMode" value="false" />

<package name="default" namespace="/" extends="struts-default">
<action name="excelAction" class="com.zhanggaosong.poi.ExcelDownloadAction">
<result name="success" type="stream">
<param name="contentType">application/vnd.ms-excel</param>
<param name="contentDisposition">attachment;filename="zhanggaosong.xls"</param>
<!-- <param name="contentDisposition">attachment;filename="${fileName}"</param> -->
<param name="inputName">excelFile</param>
</result>
</action>
</package>
</struts>