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下面简单给大家介绍poi导出配置
1.首先导入依赖
<!--poi-->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.6</version>
</dependency>2.创建工具类
package javaj.work.util;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class ExcelUtil {
//参数说明: fileName：文件名 projects：对象集合 columnNames： 列名 keys： map中的key
public static void start_download(HttpServletResponse response, String fileName, List<?> projects,
String[] columnNames, String[] keys) throws IOException {
//将集合中对象的属性 对应到 List<Map<String,Object>>
List<Map<String,Object>> list=createExcelRecord(projects, keys);
ByteArrayOutputStream os = new ByteArrayOutputStream();
try {
//将转换成的Workbook对象通过流形式下载
createWorkBook(list,keys,columnNames).write(os);
} catch (IOException e) {
e.printStackTrace();
}
byte[] content = os.toByteArray();
InputStream is = new ByteArrayInputStream(content);
// 设置response参数，可以打开下载页面
response.reset();
response.setContentType("application/vnd.ms-excel;charset=utf-8");
response.setHeader("Content-Disposition", "attachment;filename="+ new String((fileName + ".xls").getBytes(), "iso-8859-1"));
ServletOutputStream out = response.getOutputStream();
BufferedInputStream bis = null;
BufferedOutputStream bos = null;
try {
bis = new BufferedInputStream(is);
bos = new BufferedOutputStream(out);
byte[] buff = new byte[2048];
int bytesRead;
while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
bos.write(buff, 0, bytesRead);
}
} catch (final IOException e) {
throw e;
} finally {
if (bis != null)
bis.close();
if (bos != null)
bos.close();
}
}
private static List<Map<String, Object>> createExcelRecord(List<?> projects, String[] keys) {
List<Map<String, Object>> listmap = new ArrayList<Map<String, Object>>();
Map<String, Object> map = new HashMap<String, Object>();
map.put("sheetName", "sheet");
listmap.add(map);
Object project=null;
for (int j = 0; j < projects.size(); j++) {
project=projects.get(j);
Map<String, Object> mapValue = new HashMap<String, Object>();
for(int i=0; i<keys.length; i++){
mapValue.put(keys[i], getFieldValueByName(keys[i], project));
}
listmap.add(mapValue);
}
return listmap;
}
/**
* 利用反射 根据属性名获取属性值
* */
private static Object getFieldValueByName(String fieldName, Object o) {
try {
String firstLetter = fieldName.substring(0, 1).toUpperCase();
String getter = "get" + firstLetter + fieldName.substring(1);
Method method = o.getClass().getMethod(getter, new Class[] {});
Object value = method.invoke(o, new Object[] {});
return value;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
/**
* 创建excel文档对象
* @param keys list中map的key数组集合
* @param columnNames excel的列名
* */
private static Workbook createWorkBook(List<Map<String, Object>> list, String []keys, String columnNames[]) {
// 创建excel工作簿
Workbook wb = new HSSFWorkbook();
// 创建第一个sheet（页），并命名
Sheet sheet = wb.createSheet(list.get(0).get("sheetName").toString());
// 手动设置列宽。第一个参数表示要为第几列设；，第二个参数表示列的宽度，n为列高的像素数。
for(int i=0;i<keys.length;i++){
sheet.setColumnWidth((short) i, (short) (35.7 * 150));
}
// 创建第一行
Row row = sheet.createRow((short) 0);
// 创建两种单元格格式
CellStyle cs = wb.createCellStyle();
CellStyle cs2 = wb.createCellStyle();
// 创建两种字体
Font f = wb.createFont();
Font f2 = wb.createFont();
// 创建第一种字体样式（用于列名）
f.setFontHeightInPoints((short) 10);
f.setColor(IndexedColors.BLACK.getIndex());
f.setBoldweight(Font.BOLDWEIGHT_BOLD);
// 创建第二种字体样式（用于值）
f2.setFontHeightInPoints((short) 10);
f2.setColor(IndexedColors.BLACK.getIndex());
// 设置第一种单元格的样式（用于列名）
cs.setFont(f);
cs.setBorderLeft(CellStyle.BORDER_THIN);
cs.setBorderRight(CellStyle.BORDER_THIN);
cs.setBorderTop(CellStyle.BORDER_THIN);
cs.setBorderBottom(CellStyle.BORDER_THIN);
cs.setAlignment(CellStyle.ALIGN_CENTER);
// 设置第二种单元格的样式（用于值）
cs2.setFont(f2);
cs2.setBorderLeft(CellStyle.BORDER_THIN);
cs2.setBorderRight(CellStyle.BORDER_THIN);
cs2.setBorderTop(CellStyle.BORDER_THIN);
cs2.setBorderBottom(CellStyle.BORDER_THIN);
cs2.setAlignment(CellStyle.ALIGN_CENTER);
//设置列名
for(int i=0;i<columnNames.length;i++){
Cell cell = row.createCell(i);
cell.setCellValue(columnNames[i]);
cell.setCellStyle(cs);
}
//设置每行每列的值
for (short i = 1; i < list.size(); i++) {
// Row 行,Cell 方格 , Row 和 Cell 都是从0开始计数的
// 创建一行，在页sheet上
Row row1 = sheet.createRow((short) i);
// 在row行上创建一个方格
for(short j=0;j<keys.length;j++){
Cell cell = row1.createCell(j);
cell.setCellValue(list.get(i).get(keys[j]) == null?" ": list.get(i).get(keys[j]).toString());
cell.setCellStyle(cs2);
}
}
return wb;
}
}
3.pojo
public class Student {
private int no;
private String name;
private int age;
//此处省略getter和setter
}4.配置controller
@RequestMapping(value = "download")
public void index(HttpServletResponse response){
String fileName = "人员档案列表";
List<Student> students = new ArrayList<Student>();
for (int i = 0;i<20 ;i++){
Student student = new Student();
student.setAge(i+10);
student.setName("张三"+i);
student.setNo(i);
students.add(student);
}
// 列名
String columnNames[] = { "ID", "姓名", "年龄" };
// map中的key
String keys[] = { "no", "name", "age" };
try {
ExcelUtil.start_download(response, fileName, students,columnNames, keys);
} catch (IOException e) {
e.printStackTrace();
}
}5.页面
<a href="download.do">导出Excel</a>