在解決了excel兼容性問題之后, 終于可以開始制作這個(gè)小工具了, 這個(gè)工具主要是用來通過excel文件獲得JavaBean對象和Map映射的.
先說簡單的, 轉(zhuǎn)換map

    public static List<Map<String,Object>> importExcel(InputStream in) throws Exception {
        List<Map<String,Object>> mapList = new ArrayList<Map<String,Object>>();
        Workbook workbook = WorkbookFactory.create(in);
        Sheet sheet = workbook.getSheetAt(0);
        Row row = sheet.getRow(0);
        List<String> keys = new ArrayList<String>();
        for(int i = 0; i < row.getLastCellNum(); i++){
            Cell cell = row.getCell(i);
            keys.add(String.valueOf(getValue(cell)));
        }
        
        for(int i = 0; i < sheet.getLastRowNum(); i++){
            Row currentRow = sheet.getRow(i + 1);
            Map<String, Object> map = new HashMap<String, Object>();
            for(int j = 0; j < currentRow.getLastCellNum(); j++){
                map.put(keys.get(j), getValue(currentRow.getCell(j)));
            }
            mapList.add(map);
        }
        return mapList;
    }

代碼比較簡單, 不多解釋, 為了讓excel單元格取值簡單, 封裝了一個(gè)getValue方法, 代碼中有一些過期的方法, 但是沒關(guān)系... 也有點(diǎn)懶不想找替代方法了

private static Object getValue(Cell cell) {
        if (cell.getCellType() == Cell.CELL_TYPE_BOOLEAN) {
            return cell.getBooleanCellValue();
        } else if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) {
            return cell.getNumericCellValue();
        } else {
            return String.valueOf(cell.getStringCellValue());
        }
    }

接著是轉(zhuǎn)換成JavaBean的方法

    public static <T> List<T> importExcel(InputStream in, Class<T> c) throws Exception {
        List<T> list = new ArrayList<T>();
        Workbook workbook = WorkbookFactory.create(in);
        Sheet sheet = workbook.getSheetAt(0);
        Row row = sheet.getRow(0);
        List<String> keys = new ArrayList<String>();
        for(int i = 0; i < row.getLastCellNum(); i++){
            Cell cell = row.getCell(i);
            keys.add(getValue(cell));
        }
        
        for(int i = 0; i < sheet.getLastRowNum(); i++){
            Row currentRow = sheet.getRow(i + 1);
            Map<String, String> map = new HashMap<String, String>();
            for(int j = 0; j < currentRow.getLastCellNum(); j++){
                map.put(keys.get(j), getValue(currentRow.getCell(j)));
            }
            T t = mapToObject(c,map);
            list.add(t);
        }
        
        return list;
    }

總體上和轉(zhuǎn)換map的代碼差不多, 邏輯是一樣的, 為了裝逼用了泛型, 關(guān)鍵是map和javabean的轉(zhuǎn)換, 用了一個(gè)mapToObject的方法

    private static <T> T mapToObject(Class<T> c,Map<String, Object> map) throws Exception {
        BeanInfo beanInfo = Introspector.getBeanInfo(c);
        T t = c.newInstance();
        PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
        for(int i = 0; i < propertyDescriptors.length; i++){
            PropertyDescriptor descriptor = propertyDescriptors[i];
            String propertyName = descriptor.getName();
            if(map.containsKey(propertyName)){
                Object value = map.get(propertyName);
                Object[] args = new Object[1];
                args[0] = value;
                //這里捕獲異常為了讓不正常的值可以暫時(shí)跳過不影響正常字段的賦值
                try {
                    descriptor.getWriteMethod().invoke(t, args);
                } catch (IllegalAccessException e) {
                    e.printStackTrace();
                } catch (IllegalArgumentException e) {
                    e.printStackTrace();
                } catch (InvocationTargetException e) {
                    e.printStackTrace();
                }
            }
        }
        return t;
    }

以上代碼不是很嚴(yán)謹(jǐn), 希望看到問題的能交流一下, 也歡迎大家提問.

參考資料
http://poi.apache.org/apidocs/