java 利用 poi 生成 Excel文件与spring使用文件流形式下载文件

本文为结合参考资料整合而来。

第一步导包：

三个jar：

poi

poi-ooxml

poi-ooxml-schemas

maven：

<properties>
<poi.version>3.12</poi.version>
</properties>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>${poi.version}</version>
<type>pom</type>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>${poi.version}</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml-schemas</artifactId>
<version>${poi.version}</version>
</dependency>

公用类：ExcelUtil

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.CellRangeAddress;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;

/**
* Excel util, create excel sheet, cell and style.
* @param <T> generic class.
*/
public class ExcelUtil<T> {

public HSSFCellStyle getCellStyle(HSSFWorkbook workbook,boolean isHeader){
HSSFCellStyle style = workbook.createCellStyle();
style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
style.setBorderRight(HSSFCellStyle.BORDER_THIN);
style.setBorderTop(HSSFCellStyle.BORDER_THIN);
style.setLocked(true);
if (isHeader) {
style.setFillForegroundColor(HSSFColor.GREY_25_PERCENT.index);
style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
HSSFFont font = workbook.createFont();
font.setColor(HSSFColor.BLACK.index);
font.setFontHeightInPoints((short) 12);
font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
style.setFont(font);
}
return style;
}

public  void generateHeader(HSSFWorkbook workbook,HSSFSheet sheet,String[] headerColumns){
HSSFCellStyle style = getCellStyle(workbook, true);
Row row = sheet.createRow(0);
row.setHeightInPoints(30);
for(int i=0;i<headerColumns.length;i++){
Cell cell = row.createCell(i);
String[] column = headerColumns[i].split("_#_");
sheet.setColumnWidth(i, Integer.valueOf(column[1]));
cell.setCellValue(column[0]);
cell.setCellStyle(style);
}
}

public static InputStream writeExcelToStream(HSSFWorkbook workbook,HSSFSheet sheet) {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
try {
workbook.write(bos);
} catch (IOException e) {
e.printStackTrace();
}
try {
workbook.close();
} catch (IOException e) {
e.printStackTrace();
}
//数据在bos中
ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
return bis;
}

@SuppressWarnings({ "rawtypes", "unchecked" })
public  HSSFSheet creatAuditSheet(HSSFWorkbook workbook,String sheetName,
List<T> dataset,String[] headerColumns,String[] fieldColumns) throws NoSuchMethodException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {

HSSFSheet sheet = workbook.createSheet(sheetName);
//sheet.protectSheet(""); //保护生成Excel文档，设置密码访问.
//自动对生成的Excel 文档第一行标题栏设置成filter 过滤形式, 方便用户使用
char[] endChar = Character.toChars( 'A' + (headerColumns.length - 1) );
String rangeAddress = "A1:" + String.valueOf(endChar) + "1";
sheet.setAutoFilter(CellRangeAddress.valueOf(rangeAddress));

generateHeader(workbook,sheet,headerColumns);
HSSFCellStyle style = getCellStyle(workbook,false);
SimpleDateFormat sd = new SimpleDateFormat("yyyy-MM-dd");
int rowNum = 0;
for(T t:dataset){
rowNum++ ;
Row row = sheet.createRow(rowNum);
row.setHeightInPoints(25);
for(int i = 0; i < fieldColumns.length; i++){
String fieldName = fieldColumns[i] ;

String getMethodName = "get" + fieldName.substring(0,1).toUpperCase() + fieldName.substring(1);
try {
Class clazz = t.getClass();
Method getMethod;
getMethod = clazz.getMethod(getMethodName, new Class[]{} );
Object value = getMethod.invoke(t, new Object[]{});
String cellValue = "";
if (value instanceof Date){
Date date = (Date)value;
cellValue = sd.format(date);
}else{
cellValue = null != value ? value.toString() : "";
}
Cell cell = row.createCell(i);
cell.setCellStyle(style);
cell.setCellValue(cellValue);

} catch (Exception e) {

}
}
}
return sheet;
}
}

下载提供流的形式：

import org.springframework.util.FileCopyUtils;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
/**
* Download Excel Util
*/
public class ExcelOperateUtil {
public static void downloadExcel(InputStream inputStream, HttpServletResponse response, String excelName){
response.setContentType("application/vnd.ms-excel");
response.setHeader("Content-Disposition", "attachment;" + "filename=" + excelName);
try {
FileCopyUtils.copy(inputStream, response.getOutputStream());
} catch (IOException e) {
e.printStackTrace();
}
}
}

测试类：

UserTest

package ExcelTest;

public  class UserTest {

private String name;
private int age;
private String address;

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 String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}

public UserTest(String name, int age, String address) {
this.name = name;
this.age = age;
this.address = address;
}
}

PoiTest ：

package ExcelTest;
import java.io.*;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.List;
import com.fx.util.ExcelUtil;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

public class PoiTest {
/*excel column formate:column_#_width, excel中每一列的名称*/
public static final String[] USER_RECORES_COLUMNS = new String[]{
"User Name_#_3000",
"Address_#_7000"
};
/*the column will display on xls files. must the same as the entity fields.对应上面的字段.*/
public static final String[] USER_RECORES_FIELDS = new String[]{
"name","address"
};
public static void main(String[] args) throws NoSuchMethodException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, IOException {
List<UserTest> users = new ArrayList<UserTest>();
for(int i=0; i<10;i++){
UserTest u = new UserTest("name: " + i, i, "address: " + i);
users.add(u);
}
//实际项目中，这个list 是从数据库中得到的
HSSFWorkbook workbook = new HSSFWorkbook();
ExcelUtil<UserTest> UserTestSheet = new ExcelUtil<UserTest>();
HSSFSheet sheet = UserTestSheet.creatAuditSheet(workbook, "UserTest sheet xls",
users, USER_RECORES_COLUMNS, USER_RECORES_FIELDS);
/* FileOutputStream fileOut = new FileOutputStream("d:/user_test.xls");
workbook.write(fileOut);
fileOut.close();*/

ByteArrayInputStream inputStream = (ByteArrayInputStream) ExcelUtil.writeExcelToStream(workbook, sheet);

FileOutputStream fileOut = new FileOutputStream("d:/user_test1.xls");
int data=inputStream.read();
while(data!=-1){
fileOut.write(data);
data=inputStream.read();
}
fileOut.close();
}
}

运行PoiTest，可以看到声称的excel效果。

参考完全复制粘贴，文件下载参考：

http://ju.outofmemory.cn/entry/67140

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