Excel文件(xls/xlsx)轉JavaBean工具的實現

摘要 Excel文件轉換為javabean一般用Apache POI工具,這個工具是專門操作微軟辦辦公軟件的。雖然比較簡單,但是比較費時費力,沒有提供xlsToBean這樣給力的方法。這次正好有這個需求,看了同事們的方法~~Orz給跪。既然是程序猿,那么就不要用人力解決問題,而是用算法解決它,所以還是直接寫工具,方便自己,也方便他人。

先看看同事的方法

public static List<JavaBean> getListByExcel(String file) throws BiffException, IOException, MyException{
        List<JavaBean> list=new ArrayList<JavaBean>();
        Workbook rwb=Workbook.getWorkbook(new File(file));
        Sheet rs=rwb.getSheet("商品");
        if(rs==null) {
            throw new MyException("行數為零");
        }
        int rows=rs.getRows();
        for (int i = 1; i < rows; i++) {
            if(rs.getCell(0, i).getContents()==null||rs.getCell(0, i).getContents().equals("")) {
                break;
            }
            String name=rs.getCell(1, i).getContents();
            String format=rs.getCell(2, i).getContents();
            String unit=rs.getCell(3, i).getContents();
            String factory=rs.getCell(4, i).getContents();
            String price=rs.getCell(5, i).getContents();
            String conversion=rs.getCell(6, i).getContents();
            String tname=rs.getCell(7, i).getContents();
            String tformat=rs.getCell(8, i).getContents();
            String tunit=rs.getCell(9, i).getContents();
            String tfactory=rs.getCell(10, i).getContents();
            String tprice=rs.getCell(11, i).getContents();
            String tendGoodsId=rs.getCell(12, i).getContents();
            String goodsId=rs.getCell(13, i).getContents();
            String factoryId=(rs.getCell(14, i).getContents()==null||rs.getCell(14, i).getContents().equals(""))?"0":rs.getCell(14, i).getContents();
            GoodsEntity a = new GoodsEntity();
            a.setName(name);
            a.setFormat(format);
            a.setUnit(unit);
            a.setFactory(factory);
            a.setPrice(price);
            a.setTend_goodsId(tendGoodsId);
            a.setGoodsId(goodsId);
            a.setFactoryId(factoryId);
            a.setUuId(UUID.randomUUID().toString());
            a.setTfactory(tfactory);
            a.setTformat(tformat);
            a.setTname(tname);
            a.setTunit(tunit);
            a.setConversion(conversion);
            a.setTprice(tprice);
            list.add(a);
        }
        return list;
    }

這只是其中一個javabean的轉換方法。所在類里面目前有10個左右的轉換方法,但是代碼已經有484行。這個項目才剛起步,到后期豈不是要幾千行上萬行?

首先說說我的想法,直接看偽代碼比較清楚

File file = new File(excel文件); 

WorkBook wb = new Workbook(file); //excel文件轉換文檔對象

Row row = wb.getSheet(0).getRow(行號);//讀取excel一行數據
//其實到這里,一行數據就是一個JavaBean

int cols = row.getLastCellNum();//獲取最后一列的列號

Object[] arr = new Object[cols];

//遍歷這行的每一個單元格,然后把單元格取到的數據添加到數組arr
for(int i = 0 ;i<cols;i++){
  Cell cell = row.getCell(i);
  arr[i] = cell.getCellValue();
}

//ok~到此為止我們把一行數據插入到了數組。那么接下來如何把數組填充到一個javabean呢?
//我的想法:數組的下標與javabean屬性對應起來。就可以利用反射將數組的元素一一設置到javabean。

看我的代碼,不BB

ExcelCell.java 注解

/** 
* @ClassName: ExcelCell 
* @Description: 實體字段與excel列號關聯的注解
* @author albert
*  
*/
@Documented
@Inherited
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
public @interface ExcelCell {
    int col();
    Class<?> Type() default String.class;
}

Excel 文件

商品名 單位 規格 生產廠家
感冒靈顆粒 3片/盒 貴州百靈

excel文件總共有4列,那么序號0-3;

Goods.java 實體類

這里要給實體類屬性添加注解,以便與Excel 列號對應

public class Goods{
  @ExcelCell(col=0)
  private String name; //商品名

  @ExcelCell(col=1)
  private String unit; //單位

  @ExcelCell(col=2)
  private String format; //規格

  @ExcelCell(col=3)
  private String factory;//生產廠家
}

最重要的工具類:ExcelConvert.java

/**
 * 
 */
package com.sy.utils;

/** 
* @ClassName: ExcelConveter 
* @Description: 
* @author albert
* @date 2017年5月5日 下午1:19:56 
*  
*/
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellType;
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 com.sy.exceptions.MyException;

public class ExcelConveter {
    
    public static Workbook readFile(File file) throws MyException {
        try {
            //xls和xlsx必須不同的處理類,POI就這么規定的
            if (file.getName().toLowerCase().endsWith(".xls")) {
                return readFileHSSF(new FileInputStream(file));
            } else {
                return readFileXSSF(new FileInputStream(file));
            }
        } catch (Exception e) {
            e.printStackTrace();
            throw new MyException(e.getMessage());
        }
    }
    //HSSF*是處理xls格式的,XSSF是處理xlsx格式文件
    private static Workbook readFileHSSF(InputStream stream) throws MyException, IOException {
        try {
            return new HSSFWorkbook(stream);
        } catch (IOException e) {
            e.printStackTrace();
            throw new MyException(e.getMessage());
        } finally {
            stream.close();
        }
    }

    private static Workbook readFileXSSF(InputStream stream) throws MyException, IOException {
        try {
            return new XSSFWorkbook(stream);
        } catch (IOException e) {
            e.printStackTrace();
            throw new MyException(e.getMessage());
        } finally {
            stream.close();
        }
    }

    public static Workbook readFile(String path) throws MyException {
        File file = new File(path);
        if (!file.exists())
            throw new MyException("文件不存在");
        if (!file.isFile())
            throw new MyException("不是合法的文件");
        return readFile(file);
    }

    public static Sheet readSheet(HSSFWorkbook workbook, Integer index) {
        return workbook.getSheetAt(index);
    }

    public static Object[] convertArrayByRow(Row row) {
        int cols = row.getLastCellNum();
        Object[] arr = new Object[cols];
        for (int i = 0; i < cols; i++) {
            Cell cell = row.getCell(i);
            if (cell == null)
                continue;
            if (cell.getCellTypeEnum() == CellType.STRING) {
                arr[i] = cell.getStringCellValue();
            } else if (cell.getCellTypeEnum() == CellType.NUMERIC) {
                arr[i] = cell.getNumericCellValue();
            } else {

            }
        }
        return arr;
    }

    public static <T extends Object> T convertBeanFromArray(Object[] arr, Class<T> clazz) throws MyException {
        T entity;
        try {
            entity = clazz.newInstance();
            Field[] fields = clazz.getDeclaredFields();
            for (Field field : fields) {
                if (!field.isAnnotationPresent(ExcelCell.class))
                    continue;

                field.setAccessible(true);
                ExcelCell anno = field.getAnnotation(ExcelCell.class);
                Class<?> cellType = anno.Type();
                Integer col = anno.col();

                if (col >= arr.length)
                    continue;
                if (arr[col] == null)
                    continue;
                if (cellType == null) {
                    field.set(entity, arr[col]);
                } else {
                    field.set(entity, numericByStr(cellType, arr[col]));
                }
            }
            return entity;
        } catch (Exception e) {
            e.printStackTrace();
            throw new MyException(e.getMessage());
        }
    }

    public static <T extends Object> Object numericByStr(Class<T> clazz, Object param) {
        if (param == null)
            return null;
        String arg = String.valueOf(param);
        if (clazz.isAssignableFrom(Double.class)) {
            return Double.valueOf(arg);
        } else if (clazz.isAssignableFrom(Long.class)) {
            Double d = Double.valueOf(arg);
            return d.longValue();
        } else if (clazz.isAssignableFrom(Integer.class)) {
            return Integer.valueOf(arg);
        } else {
            return arg;
        }
    }

    public static <T> List<T> getBean(String path, Class<T> clazz) throws MyException {
        List<T> list = new ArrayList<T>();
        Workbook book = readFile(path);
        for (int i = 1; i <= book.getSheetAt(0).getLastRowNum(); i++) {
            Object[] arr = convertArrayByRow(book.getSheetAt(0).getRow(i));
            T t = convertBeanFromArray(arr, clazz);
            list.add(t);
        }
        return list;
    }

    public static <T> List<T> getBean(File file, Class<T> clazz) throws MyException {
        List<T> list = new ArrayList<T>();
        Workbook book = readFile(file);
        for (int i = 1; i <= book.getSheetAt(0).getLastRowNum(); i++) {
            Object[] arr = convertArrayByRow(book.getSheetAt(0).getRow(i));
            T t = convertBeanFromArray(arr, clazz);
            list.add(t);
        }
        return list;
    }

    public static <T> List<T> getBean(InputStream stream, String excelType, Class<T> clazz)
            throws MyException, IOException {
        Workbook book;
        if (excelType.equals("xls")) {
            book = readFileHSSF(stream);
        } else {
            book = readFileXSSF(stream);
        }
        List<T> list = new ArrayList<T>();
        for (int i = 1; i <= book.getSheetAt(0).getLastRowNum(); i++) {
            Object[] arr = convertArrayByRow(book.getSheetAt(0).getRow(i));
            T t = convertBeanFromArray(arr, clazz);
            list.add(t);
        }
        return list;
    }
}

使用方法:就這么一行,有沒有很簡單?

List<Goods> list = ExcelConveter.getBean('excel文件路徑', Barcode.class);

所需jar包在apache 官網就可以下載 http://poi.apache.org/download.html#POI-3.16

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