Java 通过Poi api操作(read/write)Excel

依赖jar

<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.14</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.14</version>
</dependency>

我写的工具类

package com.plugins.core.util;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.*;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
* 支持取.txt、.doc、.docx、.xls、.xlsx，5种格式文档的内容，以字符串的形式返回。
* {@link http://poi.apache.org} *
* Created by simon on 16-6-28.
*/
public class JavaExcelUtils {

//   Excel格式如下示例:

//    systemFileType    fileNo  fileName    responsibleDpt  remark
//    1                 SC0001  test1.clxs  航海部         没有备注1
//    1                 SC0002  test2.clxs  航海部         没有备注2
//    2                 SC0003  test3.clxs  航海部         没有备注3

private static final Logger logger = LoggerFactory.getLogger(JavaExcelUtils.class);

//解析Excel文件
public static List<List<Object>> parseExcel(InputStream input) throws Exception {
final DecimalFormat decimalFormat = new DecimalFormat("#.####");

final List<List<Object>> items = new ArrayList<List<Object>>();

final Workbook wb =WorkbookFactory.create(input);

final Sheet sheet = wb.getSheetAt(0);
Iterator<Row> rowIterator = sheet.iterator();
// skip the first row
if (rowIterator.hasNext()) {
rowIterator.next();
}
while (rowIterator.hasNext()) {
Row row = rowIterator.next();
List<Object> object=new ArrayList<Object>();
items.add(object);

int colIndex = 0;
Iterator<Cell> cellIterator = row.cellIterator();
while (cellIterator.hasNext()) {
Cell cell = cellIterator.next();
String value = getCellValueAsString(cell, decimalFormat);
switch(colIndex) {
case 0: //文件类型
object.add(value);
break;
case 1: //文件编号
object.add(value);
break;
case 2: //文件名称
object.add(value);
break;
case 3: ////responsibleDpt
object.add(value);
break;
default:
object.add(value);
break;
}
colIndex++;
}
}
wb.close();
return items;
}

public  static byte[] createExcel(List<List<Object>> lists) throws Exception {
Workbook wb = new HSSFWorkbook();
Sheet sheet = wb.createSheet("Sheet 1");
// Create a row and put some cells in it. Rows are 0 based.
int colIndex = 0;
Row row = sheet.createRow(0);
row.createCell(colIndex++).setCellValue("systemFileType");
row.createCell(colIndex++).setCellValue("fileNo");
row.createCell(colIndex++).setCellValue("fileName");
row.createCell(colIndex++).setCellValue("responsibleDpt");
row.createCell(colIndex++).setCellValue("remark");

int rowIndex = 1;
for (List<Object> item : lists) {
colIndex = 0; // 重置列索引为0
row = sheet.createRow(rowIndex);
for(int i=0;i<item.size();i++){
row.createCell(colIndex++).setCellValue(item.get(i).toString());
}
rowIndex++;
}

ByteArrayOutputStream output = new ByteArrayOutputStream();
wb.write(output);
output.close();
wb.close();
return output.toByteArray();
}

// byte[] to file
public static void getFile(byte[] bfile, String filePath,String fileName) {
BufferedOutputStream bos = null;
FileOutputStream fos = null;
File file = null;
try {
File dir = new File(filePath);
if(!dir.exists()&&dir.isDirectory()){//判断文件目录是否存在
dir.mkdirs();
}
file = new File(filePath+File.separator+fileName);
fos = new FileOutputStream(file);
bos = new BufferedOutputStream(fos);
bos.write(bfile);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (bos != null) {
try {
bos.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
if (fos != null) {
try {
fos.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
}

private static String getCellValueAsString(Cell cell, DecimalFormat decimalFormat) {
switch (cell.getCellType()) {
case Cell.CELL_TYPE_NUMERIC:
double numericCellValue = cell.getNumericCellValue();
return decimalFormat.format(numericCellValue);
case Cell.CELL_TYPE_STRING:
return cell.getStringCellValue();
case Cell.CELL_TYPE_BOOLEAN:
return String.valueOf(cell.getBooleanCellValue());
default:
break;
}
return null;
}
}

我写的测试类

@Test
public  void  test45() throws Exception {
System.out.println("start......");
File file=new File("/software/mine-workspace/idea/platform/data/filestorage/1/201606/2815/2348/5de92fb8-c6ce-4ed5-9e8f-b0da0816ce0e.xlsx");
InputStream inputStream=new FileInputStream(file);
List<List<Object>> lists= JavaExcelUtils.parseExcel(inputStream);
for (List<Object> o:lists){
for(int i=0;i<o.size();i++){
System.out.print(o.get(i)+"\t");
}
System.out.println();
}

System.out.println("write.....");
byte[] bytes=JavaExcelUtils.createExcel(lists);
JavaExcelUtils.getFile(bytes,"/home/simon/桌面/","data.xlsx");
System.out.println("end..........");
}