用Java玩轉(zhuǎn)Excel，竟然如此easy~

<dependency>    <groupId>org.apache.poigroupId>    <artifactId>poiartifactId>    <version>3.9version>dependency><dependency>    <groupId>org.apache.poigroupId>    <artifactId>poi-ooxmlartifactId>    <version>3.9version>dependency>

HSSF is the POI Project's pure Java implementation of the Excel '97(-2007) file format.XSSF?is?the?POI?Project's?pure?Java?implementation?of?the?Excel?2007?OOXML?(.xlsx)?file?format.

//直接創(chuàng)建新的HSSFWorkbook()
//通過(guò)輸入流創(chuàng)建HSSFWorkbook(java.io.InputStream s)

//直接創(chuàng)建新的XSSFWorkbook()
//通過(guò)File類創(chuàng)建XSSFWorkbook(java.io.File file)
//通過(guò)輸入流創(chuàng)建XSSFWorkbook(java.io.InputStream is)

workbook.createSheet();workbook.createSheet(String?sheetName);

sheet.createRow(int rownum);

row.createCell(int?column);row.createCell(int?column,?int?type);

import java.io.*;import org.apache.poi.xssf.usermodel.*;public class CreateWorkBook{   public static void main(String[] args)throws Exception   {      //Create Blank workbook      XSSFWorkbook workbook = new XSSFWorkbook();      //Create file system using specific name      FileOutputStream out = new FileOutputStream(      new File("createworkbook.xlsx"));      //write operation workbook using file out object      workbook.write(out);      out.close();      System.out.println("      createworkbook.xlsx written successfully");   }}

import java.io.*;import org.apache.poi.xssf.usermodel.*;public class OpenWorkBook
   public static void main(String args[])throws Exception      File file = new File("openworkbook.xlsx");      FileInputStream fIP = new FileInputStream(file);      //Get the workbook instance for XLSX file      XSSFWorkbook workbook = new XSSFWorkbook(fIP);      if(file.isFile() && file.exists())      {         System.out.println(         "openworkbook.xlsx file open successfully.");      }      else      {         System.out.println(         "Error to open openworkbook.xlsx file.");      }   }}

@Excel(name = "學(xué)生標(biāo)簽頁(yè)")public class Student {
    @Excel(name = "姓名")    private String name;
    private boolean male;
    @Excel(name = "身高")    private int height;
    public String getName() {        return name;    }
    public void setName(String name) {        this.name = name;    }
    public boolean isMale() {        return male;    }
    public void setMale(boolean male) {        this.male = male;    }
    public int getHeight() {        return height;    }
    public void setHeight(int height) {        this.height = height;    }}

public static void main(String[] args) {    List list = new ArrayList();    Student student1 = new Student();    student1.setName("小紅");    student1.setMale(false);    student1.setHeight(167);
    Student student2 = new Student();    student2.setName("小明");    student2.setMale(true);    student2.setHeight(185);
    list.add(student1);    list.add(student2);
    File file = new File("C:/Users/Dulk/Desktop/1314.xls");    createExcel(list, file);}

import?java.lang.annotation.Retention;import?java.lang.annotation.RetentionPolicy;

@Retention(RetentionPolicy.RUNTIME)public?@interface?Excel?{????//設(shè)置名稱????public?String?name()?default?"";}

import org.apache.log4j.Logger;import org.apache.poi.hssf.usermodel.HSSFWorkbook;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;import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.lang.reflect.Field;import java.lang.reflect.InvocationTargetException;import java.lang.reflect.Method;import java.util.ArrayList;import java.util.List;
/** * Excel的操作工具類 */public class ExcelUtil {    private static Logger log = Logger.getLogger(ExcelUtil.class);
    /**     * 獲取某個(gè)File文件對(duì)應(yīng)的Workbook工作簿對(duì)象     */    public static Workbook gainWorkbook(File file) throws ExcelException {        if (!isExcel(file)) {            throw new ExcelException("文件不是Excel類型");        }        //如果文件不存在則新建        if (!file.exists()) {            try {                OutputStream os = new FileOutputStream(file);                Workbook workbook = isOlderEdition(file) ? new HSSFWorkbook() : new XSSFWorkbook();                workbook.write(os);                log.debug("文件不存在，新建該Excel文件");                os.close();
            } catch (FileNotFoundException e) {                e.printStackTrace();            } catch (IOException e) {                e.printStackTrace();            }        }
        try {            InputStream is = new FileInputStream(file);            return isOlderEdition(file) ? new HSSFWorkbook(is) : new XSSFWorkbook(is);
        } catch (FileNotFoundException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }
        return null;    }
    /**     * 判斷某個(gè)Excel文件是否是2003-2007通用舊版     */    private static boolean isOlderEdition(File file) {        return file.getName().matches(".+\\.(?i)xls");    }
    /**     * 判斷文件是否是一個(gè)Excel文件     */    private static boolean isExcel(File file) {        String fileName = file.getName();        String regXls = ".+\\.(?i)xls";        String regXlsx = ".+\\.(?i)xlsx";        return fileName.matches(regXls) || fileName.matches(regXlsx);    }
    /**     * 將某個(gè)對(duì)象的List轉(zhuǎn)換為Excel工作簿     */    public static  Workbook createExcel(List list, File file) {        String sheetName = "default";        if (list.size() == 0) {            return null;        }
        Workbook workbook = null;        try {            Class clazz = list.get(0).getClass();            Field[] fields = clazz.getDeclaredFields();            if (clazz.isAnnotationPresent(Excel.class)) {                Excel excel = (Excel) clazz.getAnnotation(Excel.class);                sheetName = excel.name();            }
            workbook = gainWorkbook(file);            Sheet sheet = workbook.createSheet(sheetName);            //創(chuàng)建首行            Row line = sheet.createRow(0);            for (int k = 0; k < fields.length; k++) {                Cell cell = line.createCell(k);                String columnName = fields[k].getName();                if (fields[k].isAnnotationPresent(Excel.class)) {                    Excel excel = fields[k].getAnnotation(Excel.class);                    columnName = excel.name();                }                cell.setCellValue(columnName);            }            //創(chuàng)建數(shù)據(jù)            for (int i = 1; i <= list.size(); i++) {                Row row = sheet.createRow(i);                for (int j = 1; j <= fields.length; j++) {                    Cell cell = row.createCell(j - 1);                    String fieldName = fields[j - 1].getName();                    String fieldFirstLetterUpper = fieldName.substring(0, 1).toUpperCase();                    String prefix = "get";                    if ("boolean".equals(fields[j - 1].getType().getName())) {                        prefix = "is";                    }                    String methodName = prefix + fieldFirstLetterUpper + fieldName.substring(1);                    Method method = clazz.getMethod(methodName);                    cell.setCellValue(String.valueOf(method.invoke(list.get(i - 1))));                }            }            log.debug("List讀入完畢");            OutputStream os = new FileOutputStream(file);            workbook.write(os);            os.close();
        } catch (ExcelException e) {            e.printStackTrace();        } catch (InvocationTargetException e) {            e.printStackTrace();        } catch (NoSuchMethodException e) {            e.printStackTrace();        } catch (IllegalAccessException e) {            e.printStackTrace();        } catch (FileNotFoundException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }        return workbook;    }}