需要引入poi的相关jar包即可。
1.ExcelHandle 判断Excel的格式
import java.io.File;
import java.io.FileInputStream;import java.io.IOException;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public class ExcelHandle {
private static final String EXCEL_XLS = "xls";
private static final String EXCEL_XLSX = "xlsx";
/**
* Judging the version of Excel
* @param in
* @param filename
* @return
* @throws IOException
*/
public static Workbook getWorkbook(File file) throws IOException{
Workbook wb = null;
FileInputStream in = new FileInputStream(file);
if(file.getName().endsWith(EXCEL_XLS)){ //Excel 2003
wb = new HSSFWorkbook(in);
System.out.println("Excel file type:xls");
}else if(file.getName().endsWith(EXCEL_XLSX)){ // Excel 2007/2010
wb = new XSSFWorkbook(in);
System.out.println("Excel file type:xlsx");
}
return wb;
}
}
2.ParseExcel用来解析Excel，一行一行读取
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
public class ParseExcel{
/**
* Read Excel test, compatible with Excel 2003/2007/2010
* @throws Exception
*/
public static void parse_excel(Workbook workbook) {
int sheetCount = workbook.getNumberOfSheets(); // Total number of sheets
for(int s = 0; s < sheetCount; s++) {
System.out.println("————————————————————————Start processing sheet"+(s+1)+"————————————————————————");
String sheetname = workbook.getSheetName(s);
System.out.println("Name of sheet"+(s+1)+":"+sheetname);
//Set the subscript of the excel sheet: 0 start
Sheet sheet = workbook.getSheetAt(s);//The first sheet
// Set the count to skip the first line of the directory
int count = 0;
//Total number of rows
int rowLength = sheet.getLastRowNum()+1;
System.out.println("Total number of rows:"+rowLength);
//Get the first line
Row rowzero = sheet.getRow(0);
//Total number of columns
int colLength = rowzero.getLastCellNum();
System.out.println("Total number of columns:"+colLength);
for (int i = 0; i < rowLength;i++) {
Row row = sheet.getRow(i);
for (int j = 0; j < colLength; j++) {
Cell cell = row.getCell(j);
if(cell==null || "".equals(cell.toString())){
System.out.print("null"+" ");
}else{
System.out.print(cell.toString()+" ");
}
}
System.out.println();
}
System.out.println("————————————————————————sheet"+(s+1)+" processing ends————————————————————————");
}
}
}
3.OutputToExcel往Excel写入数据
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
public class OutputToExcel{
public static void outputtoexcel(Workbook workbook) {
OutputStream out = null;
int sheetCount = workbook.getNumberOfSheets(); //Total number of sheets
try {
for(int s = 0; s < sheetCount; s++) {
System.out.println("————————————————————————Start processing sheet"+(s+1)+"————————————————————————");
String sheetname = workbook.getSheetName(s);
System.out.println("Name of sheet"+(s+1)+":"+sheetname);
//Set the subscript of the excel sheet: 0 start
Sheet sheet = workbook.getSheetAt(s);//The first sheet
// Set the count to skip the first line of the directory
int count = 0;
//Total number of rows
int rowLength = sheet.getLastRowNum()+1;
System.out.println("Total number of rows:"+rowLength);
//Get the first line
Row rowzero = sheet.getRow(0);
//Total number of columns
int colLength = rowzero.getLastCellNum();
System.out.println("Total number of columns:"+colLength);
//Determine if the result column already exists, create it without
if("Result".equals(rowzero.getCell(colLength-1).getStringCellValue())) {
colLength = colLength-1;
}else {
/**
* Write a new column to the sheet
*/
Cell newcell = rowzero.createCell(colLength);
newcell.setCellValue("Result");
}
/*
for (int i = 0; i < rowLength;i++) {
Row row = sheet.getRow(i);
for (int j = 0; j < colLength; j++) {
Cell cell = row.getCell(j);
if(cell==null || "".equals(cell.toString())){
System.out.print("null"+" ");
}else{
System.out.print(cell.toString()+" ");
}
}
System.out.println();
} */
int writeflag = 1;//Line number written
for(int j = 0 ; j < (rowLength-1)/15; j++) {
/**
* Write results back to sheet
*/
Row writerow = sheet.getRow(writeflag);
Cell writecell = writerow.createCell(colLength);
writecell.setCellValue("true");
writeflag+=15;
}
// Create file output and prepare output table
out = new FileOutputStream("C:\\Users\\test.xlsx");
workbook.write(out);
System.out.println("Data written successfully");
System.out.println("————————————————————————sheet"+(s+1)+" processing ends————————————————————————");
}
} catch (Exception e) {
e.printStackTrace();
} finally{
try {
if(out != null){
out.flush();
out.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
4.测试方法
public static void main(String[] args) {
// TODO Auto-generated method stub
try {
File file = new File("C:\\Users\\test.xlsx");
Workbook workbook = ExcelHandle.getWorkbook(file);
OutputToExcel.outputtoexcel(workbook);
//ParseExcel.parse_excel(workbook);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}