Excel文件操作

package com.zzy.skd.dao.utils;

import java.io.InputStream;
import java.lang.reflect.Field;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map.Entry;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.exception.ExceptionUtils;
import org.apache.commons.lang3.math.NumberUtils;
import org.apache.commons.lang3.time.DateUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import jxl.Cell;
import jxl.Sheet;
import jxl.Workbook;

public class ExcelUtils {
    private static final Logger LOGGER = LoggerFactory.getLogger(ExcelUtils.class);

    /**
     * 将Excel转化为List
     *
     * @param in ：承载着Excel的输入流
     * @param sheetName ：要导入的工作表序号
     * @param entityClass ：List中对象的类型（Excel中的每一行都要转化为该类型的对象）
     * @param fieldMap ：Excel中的中文列头和类的英文属性的对应关系Map
     * @param uniqueFields ：指定业务主键组合（即复合主键），这些列的组合不能重复
     * @return list集合
     * @throws Exception 异常
     */
    public static <T> List<T> excelToList(InputStream in, String sheetName, Class<T> entityClass,
            LinkedHashMap<String, String> fieldMap, String[] uniqueFields) throws Exception {

        // 定义要返回的list
        List<T> resultList = new ArrayList<T>();

        try {

            // 根据Excel数据源创建WorkBook
            Workbook wb = Workbook.getWorkbook(in);
            // 获取工作表
            Sheet sheet = null;
            if(StringUtils.isNotBlank(sheetName)){
                sheet = wb.getSheet(sheetName);
            }else{
                sheet = wb.getSheet(0);
            }

            // 获取工作表的有效行数
            int realRows = 0;
            for (int i = 0; i < sheet.getRows(); i++) {

                int nullCols = 0;
                for (int j = 0; j < sheet.getColumns(); j++) {
                    Cell currentCell = sheet.getCell(j, i);
                    if (currentCell == null || "".equals(currentCell.getContents().toString())) {
                        nullCols++;
                    }
                }

                if (nullCols == sheet.getColumns()) {
                    break;
                } else {
                    realRows++;
                }
            }

            // 如果Excel中没有数据则提示错误
            if (realRows <= 1) {
                LOGGER.error("[ExcelUtil][listToExcel] no data row is  {}", realRows);
                throw new Exception("Excel文件中没有任何数据");
            }
            // 如果Excel中数据太大
            if (realRows > 20001) {
                LOGGER.error("[ExcelUtil][listToExcel] realRows is out of 20000! current row is {}", realRows);
                throw new Exception("Excel文件中数据行数 " + realRows + " 超过两万，请分批导入");
            }
            Cell[] firstRow = sheet.getRow(0);

            String[] excelFieldNames = new String[firstRow.length];

            // 获取Excel中的列名
            for (int i = 0; i < firstRow.length; i++) {
                excelFieldNames[i] = firstRow[i].getContents().toString().trim();
            }

            // 判断需要的字段在Excel中是否都存在
            boolean isExist = true;
            List<String> excelFieldList = Arrays.asList(excelFieldNames);
            for (String cnName : fieldMap.keySet()) {
                if (!excelFieldList.contains(cnName)) {
                    isExist = false;
                    break;
                }
            }

            // 如果有列名不存在，则抛出异常，提示错误
            if (!isExist) {
                throw new Exception("Excel中缺少必要的字段，或字段名称有误");
            }

            // 将列名和列号放入Map中,这样通过列名就可以拿到列号
            LinkedHashMap<String, Integer> colMap = new LinkedHashMap<String, Integer>();
            for (int i = 0; i < excelFieldNames.length; i++) {
                colMap.put(excelFieldNames[i], firstRow[i].getColumn());
            }

            // 判断是否有重复行
            // 1.获取uniqueFields指定的列
            Cell[][] uniqueCells = new Cell[uniqueFields.length][];
            for (int i = 0; i < uniqueFields.length; i++) {
                int col = colMap.get(uniqueFields[i]);
                uniqueCells[i] = sheet.getColumn(col);
            }

            // 2.从指定列中寻找重复行
            for (int i = 1; i < realRows; i++) {
                int nullCols = 0;
                for (int j = 0; j < uniqueFields.length; j++) {
                    String currentContent = uniqueCells[j][i].getContents();
                    Cell sameCell = sheet.findCell(currentContent, uniqueCells[j][i].getColumn(),
                            uniqueCells[j][i].getRow() + 1, uniqueCells[j][i].getColumn(),
                            uniqueCells[j][realRows - 1].getRow(), true);
                    if (sameCell != null) {
                        nullCols++;
                    }
                }

                if (nullCols == uniqueFields.length) {
                    throw new Exception("Excel中有重复行，请检查");
                }
            }

            // 将sheet转换为list
            for (int i = 1; i < realRows; i++) {
                // 新建要转换的对象
                T entity = entityClass.newInstance();

                // 给对象中的字段赋值
                for (Entry<String, String> entry : fieldMap.entrySet()) {
                    // 获取中文字段名
                    String cnNormalName = entry.getKey();
                    // 获取英文字段名
                    String enNormalName = entry.getValue();
                    // 根据中文字段名获取列号
                    int col = colMap.get(cnNormalName);
                    // 获取当前单元格中的内容
                    String content = sheet.getCell(col, i).getContents().toString().trim();
                    // 给对象赋值
                    setFieldValueByName(enNormalName, content, entity);
                }

                resultList.add(entity);
            }
        } catch (Exception e) {
            LOGGER.error("[ExcelUtil][listToExcel] error!{}", ExceptionUtils.getStackTrace(e));
            // 如果是Exception，则直接抛出
            if (e instanceof Exception) {
                throw (Exception) e;
                // 否则将其它异常包装成Exception再抛出
            } else {
                throw new Exception("导入Excel失败");
            }
        }
        return resultList;
    }

    /**
     * 根据字段名给对象的字段赋值
     *
     * @param fieldName 字段名
     * @param fieldValue 字段值
     * @param o 对象
     * @throws Exception 异常
     */
    public static void setFieldValueByName(String fieldName, Object fieldValue, Object o) throws Exception {

        Field field = getFieldByName(fieldName, o.getClass());
        if (field != null) {
            field.setAccessible(true);
            // 获取字段类型
            Class<?> fieldType = field.getType();

            // 根据字段类型给字段赋值
            if (String.class == fieldType) {
                field.set(o, String.valueOf(fieldValue));
            } else if ((Integer.TYPE == fieldType) || (Integer.class == fieldType)) {
                if (NumberUtils.isNumber(fieldValue.toString())) {
                    field.set(o, NumberUtils.toInt(fieldValue.toString()));
                }
            } else if ((Long.TYPE == fieldType) || (Long.class == fieldType)) {
                if (NumberUtils.isNumber(fieldValue.toString())) {
                    field.set(o, NumberUtils.toLong(fieldValue.toString()));
                }
            } else if ((Float.TYPE == fieldType) || (Float.class == fieldType)) {
                if (NumberUtils.isNumber(fieldValue.toString())) {
                    field.set(o, NumberUtils.toFloat(fieldValue.toString()));
                }
            } else if ((Short.TYPE == fieldType) || (Short.class == fieldType)) {
                if (NumberUtils.isNumber(fieldValue.toString())) {
                    field.set(o, NumberUtils.toShort(fieldValue.toString()));
                }
            } else if ((Double.TYPE == fieldType) || (Double.class == fieldType)) {
                if (NumberUtils.isNumber(fieldValue.toString())) {
                    field.set(o, NumberUtils.toDouble(fieldValue.toString()));
                }
            } else if (Character.TYPE == fieldType) {
                if ((fieldValue != null) && (StringUtils.isNotBlank(fieldValue.toString()))) {
                    field.set(o, Character.valueOf(fieldValue.toString().charAt(0)));
                }
            } else if (Date.class == fieldType) {
                Date date = DateUtils.parseDate(fieldValue.toString(), "yyyy-MM-dd", "yyyy/MM/dd", "yyyy-MM-dd HH:mm:ss");
                field.set(o, date);
            } else if (BigDecimal.class == fieldType) {
                if (NumberUtils.isNumber(fieldValue.toString())) {
                    field.set(o, new BigDecimal(fieldValue.toString()));
                }
            } else {
                field.set(o, fieldValue);
            }
        } else {
            throw new Exception(o.getClass().getSimpleName() + "类不存在字段名 " + fieldName);
        }
    }

    /**
     * 根据字段名获取字段
     *
     * @param fieldName 字段名
     * @param clazz 包含该字段的类
     * @return 字段
     */
    public static Field getFieldByName(String fieldName, Class<?> clazz) {
        // 拿到本类的所有字段
        Field[] selfFields = clazz.getDeclaredFields();

        // 如果本类中存在该字段，则返回
        for (Field field : selfFields) {
            if (field.getName().equals(fieldName)) {
                return field;
            }
        }

        // 否则，查看父类中是否存在此字段，如果有则返回
        Class<?> superClazz = clazz.getSuperclass();
        if (superClazz != null && superClazz != Object.class) {
            return getFieldByName(fieldName, superClazz);
        }

        // 如果本类和父类都没有，则返回空
        return null;
    }

}