Jeesite-導入導出源碼跟蹤分析（導入）

在使用Excel導入的時候，我們的思想基本上和導出是一樣的，但是要先讀取Excel中的數據，然後遍歷cell，並且判斷類型，最終導入我們的數據

導入工具類

` public class ImportExcel {

private static Logger log = LoggerFactory.getLogger(ImportExcel.class);

/**
 * 工作薄對象
 */
private Workbook wb;

/**
 * 工作表對象
 */
private Sheet sheet;

/**
 * 標題行號
 */
private int headerNum;

/**
 * 構造函數
 * @param path 導入文件，讀取第一個工作表
 * @param headerNum 標題行號，數據行號=標題行號+1
 * @throws InvalidFormatException 
 * @throws IOException 
 */
public ImportExcel(String fileName, int headerNum) 
        throws InvalidFormatException, IOException {
    this(new File(fileName), headerNum);
}

/**
 * 構造函數
 * @param path 導入文件對象，讀取第一個工作表
 * @param headerNum 標題行號，數據行號=標題行號+1
 * @throws InvalidFormatException 
 * @throws IOException 
 */
public ImportExcel(File file, int headerNum) 
        throws InvalidFormatException, IOException {
    this(file, headerNum, 0);
}

/**
 * 構造函數
 * @param path 導入文件
 * @param headerNum 標題行號，數據行號=標題行號+1
 * @param sheetIndex 工作表編號
 * @throws InvalidFormatException 
 * @throws IOException 
 */
public ImportExcel(String fileName, int headerNum, int sheetIndex) 
        throws InvalidFormatException, IOException {
    this(new File(fileName), headerNum, sheetIndex);
}

/**
 * 構造函數
 * @param path 導入文件對象
 * @param headerNum 標題行號，數據行號=標題行號+1
 * @param sheetIndex 工作表編號
 * @throws InvalidFormatException 
 * @throws IOException 
 */
public ImportExcel(File file, int headerNum, int sheetIndex) 
        throws InvalidFormatException, IOException {
    this(file.getName(), new FileInputStream(file), headerNum, sheetIndex);
}

/**
 * 構造函數
 * @param file 導入文件對象
 * @param headerNum 標題行號，數據行號=標題行號+1
 * @param sheetIndex 工作表編號
 * @throws InvalidFormatException 
 * @throws IOException 
 */
public ImportExcel(MultipartFile multipartFile, int headerNum, int sheetIndex) 
        throws InvalidFormatException, IOException {
    this(multipartFile.getOriginalFilename(), multipartFile.getInputStream(), headerNum, sheetIndex);
}

/**
 * 構造函數
 * @param path 導入文件對象
 * @param headerNum 標題行號，數據行號=標題行號+1
 * @param sheetIndex 工作表編號
 * @throws InvalidFormatException 
 * @throws IOException 
 */
public ImportExcel(String fileName, InputStream is, int headerNum, int sheetIndex) 
        throws InvalidFormatException, IOException {
    if (StringUtils.isBlank(fileName)){
        throw new RuntimeException("導入文檔爲空!");
    }else if(fileName.toLowerCase().endsWith("xls")){    
        this.wb = new HSSFWorkbook(is);    
    }else if(fileName.toLowerCase().endsWith("xlsx")){  
        this.wb = new XSSFWorkbook(is);
    }else{  
        throw new RuntimeException("文檔格式不正確!");
    }  
    if (this.wb.getNumberOfSheets()<sheetIndex){
        throw new RuntimeException("文檔中沒有工作表!");
    }
    this.sheet = this.wb.getSheetAt(sheetIndex);
    this.headerNum = headerNum;
    log.debug("Initialize success.");
}

/**
 * 獲取行對象
 * @param rownum
 * @return
 */
public Row getRow(int rownum){
    return this.sheet.getRow(rownum);
}

/**
 * 獲取數據行號
 * @return
 */
public int getDataRowNum(){
    return headerNum+1;
}

/**
 * 獲取最後一個數據行號
 * @return
 */
public int getLastDataRowNum(){
    return this.sheet.getLastRowNum()+headerNum;
}

/**
 * 獲取最後一個列號
 * @return
 */
public int getLastCellNum(){
    return this.getRow(headerNum).getLastCellNum();
}

/**
 * 獲取單元格值
 * @param row 獲取的行
 * @param column 獲取單元格列號
 * @return 單元格值
 */
public Object getCellValue(Row row, int column){
    Object val = "";
    try{
        Cell cell = row.getCell(column);
        if (cell != null){
            if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC){
                val = cell.getNumericCellValue();
            }else if (cell.getCellType() == Cell.CELL_TYPE_STRING){
                val = cell.getStringCellValue();
            }else if (cell.getCellType() == Cell.CELL_TYPE_FORMULA){
                val = cell.getCellFormula();
            }else if (cell.getCellType() == Cell.CELL_TYPE_BOOLEAN){
                val = cell.getBooleanCellValue();
            }else if (cell.getCellType() == Cell.CELL_TYPE_ERROR){
                val = cell.getErrorCellValue();
            }
        }
    }catch (Exception e) {
        return val;
    }
    return val;
}

/**
 * 獲取導入數據列表
 * @param cls 導入對象類型
 * @param groups 導入分組
 */
public <E> List<E> getDataList(Class<E> cls, int... groups) throws InstantiationException, IllegalAccessException,RuntimeException{
    List<Object[]> annotationList = Lists.newArrayList();
    // Get annotation field 
    Field[] fs = cls.getDeclaredFields();
    for (Field f : fs){
        ExcelField ef = f.getAnnotation(ExcelField.class);
        if (ef != null && (ef.type()==0 || ef.type()==2)){
            if (groups!=null && groups.length>0){
                boolean inGroup = false;
                for (int g : groups){
                    if (inGroup){
                        break;
                    }
                    for (int efg : ef.groups()){
                        if (g == efg){
                            inGroup = true;
                            annotationList.add(new Object[]{ef, f});
                            break;
                        }
                    }
                }
            }else{
                annotationList.add(new Object[]{ef, f});
            }
        }
    }
    // Get annotation method
    Method[] ms = cls.getDeclaredMethods();
    for (Method m : ms){
        ExcelField ef = m.getAnnotation(ExcelField.class);
        if (ef != null && (ef.type()==0 || ef.type()==2)){
            if (groups!=null && groups.length>0){
                boolean inGroup = false;
                for (int g : groups){
                    if (inGroup){
                        break;
                    }
                    for (int efg : ef.groups()){
                        if (g == efg){
                            inGroup = true;
                            annotationList.add(new Object[]{ef, m});
                            break;
                        }
                    }
                }
            }else{
                annotationList.add(new Object[]{ef, m});
            }
        }
    }
    // Field sorting
    Collections.sort(annotationList, new Comparator<Object[]>() {
        public int compare(Object[] o1, Object[] o2) {
            return new Integer(((ExcelField)o1[0]).sort()).compareTo(
                    new Integer(((ExcelField)o2[0]).sort()));
        };
    });

    Row checkrow = this.getRow(1);
    int checkcolumn = 0;
    for (Object obj[] : annotationList) {
        Object val = this.getCellValue(checkrow, checkcolumn++);
        if(val==null){
            val = "";
        }
        ExcelField ef = (ExcelField) obj[0];
        if(!val.toString().equals(ef.title())){
            if(StringUtils.isEmpty(val.toString())){
                log.info("excel異常:"+val.toString()+":"+ef.title());
                throw new RuntimeException(ef.title()+"列不存在,請重新下載模板!");
            }
            if(StringUtils.isNotEmpty(val.toString())&&StringUtils.isNotEmpty(ef.title())){
                log.info("excel異常:"+val.toString()+":"+ef.title());
                throw new RuntimeException("excel表格列對應不一致,請重新下載模板!");
            }
        }
    }

    //log.debug("Import column count:"+annotationList.size());
    // Get excel data
    List<E> dataList = Lists.newArrayList();
    for (int i = this.getDataRowNum(); i < this.getLastDataRowNum(); i++) {
        E e = (E)cls.newInstance();
        int column = 0;
        Row row = this.getRow(i);
        StringBuilder sb = new StringBuilder();
        for (Object[] os : annotationList){
            Object val = this.getCellValue(row, column++);
            if (val != null){
                ExcelField ef = (ExcelField)os[0];
                // If is dict type, get dict value
                if (StringUtils.isNotBlank(ef.dictType())){
                    String oldVal = val.toString();
                    val = DictUtils.getDictValue(val.toString().trim(), ef.dictType(), val.toString());
                    if(StringUtils.isEmpty(val.toString())){
                        val = com.cyou.seal.modules.network.utils.DictUtils.getDictValue(val.toString().trim(), ef.dictType(), val.toString());
                    }
                    if(e.getClass().getName().equals("com.cyou.seal.modules.application.VO.AssetQueryImportVO")){
                        if("[empty]".equals(val)){
                            val = "[empty]";
                        }
                    }else if(!oldVal.equals("") && val.toString().equals("")) {
                        throw new RuntimeException(ef.title()+",沒有找到【"+oldVal+"】的數據字典值");
                    }
                    //log.debug("Dictionary type value: ["+i+","+colunm+"] " + val);
                }
                // Get param type and type cast
                Class<?> valType = Class.class;
                if (os[1] instanceof Field){
                    valType = ((Field)os[1]).getType();
                }else if (os[1] instanceof Method){
                    Method method = ((Method)os[1]);
                    if ("get".equals(method.getName().substring(0, 3))){
                        valType = method.getReturnType();
                    }else if("set".equals(method.getName().substring(0, 3))){
                        valType = ((Method)os[1]).getParameterTypes()[0];
                    }
                }
                //log.debug("Import value type: ["+i+","+column+"] " + valType);
                try {
                    if (valType == String.class){
                        String s = String.valueOf(val.toString());
                        if(StringUtils.endsWith(s, ".0")){
                            val = StringUtils.substringBefore(s, ".0");
                        }else{
                            val = String.valueOf(val.toString());
                        }
                    }else if (valType == Integer.class){
                        val = Double.valueOf(val.toString()).intValue();
                    }else if (valType == Long.class){
                        val = Double.valueOf(val.toString()).longValue();
                    }else if (valType == Double.class){
                        val = Double.valueOf(val.toString());
                    }else if (valType == Float.class){
                        val = Float.valueOf(val.toString());
                    }else if (valType == Date.class){
                        val = DateUtil.getJavaDate((Double)val);
                    }else{
                        if (ef.fieldType() != Class.class){
                            val = ef.fieldType().getMethod("getValue", String.class).invoke(null, val.toString());
                        }else{
                            val = Class.forName(this.getClass().getName().replaceAll(this.getClass().getSimpleName(), 
                                    "fieldtype."+valType.getSimpleName()+"Type")).getMethod("getValue", String.class).invoke(null, val.toString());
                        }
                    }
                } catch (Exception ex) {
                    log.info("Get cell value ["+i+","+column+"] error: " + ex.toString());
                    val = null;
                }
                // set entity value
                if (os[1] instanceof Field){
                    Reflections.invokeSetter(e, ((Field)os[1]).getName(), val);
                }else if (os[1] instanceof Method){
                    String mthodName = ((Method)os[1]).getName();
                    if ("get".equals(mthodName.substring(0, 3))){
                        mthodName = "set"+StringUtils.substringAfter(mthodName, "get");
                    }
                    Reflections.invokeMethod(e, mthodName, new Class[] {valType}, new Object[] {val});
                }
            }
            sb.append(val+", ");
        }
        dataList.add(e);
        log.debug("Read success: ["+i+"] "+sb.toString());
    }
    return dataList;
}

} `

如何使用這個工具類

1.初始化:ImportExcel

ImportExcel ei = new ImportExcel(file, 1, 0);

我們跟蹤初始化代碼：獲取文檔的文件名稱，判斷是否爲空，是否是.xls或者.xlsx,判斷文檔中是否有工作表，獲取到對應的工作表，和標題行

2.調用getDataList獲取Excel中映射得到的實體List 在這個方法裏面，跟導出類型，就不多做解釋。獲取帶有ExcelField註解的字段，在獲取帶有ExcelField的方法。將遍歷得到的數據放到List。排序。我們最終得到的這個List我們還需要進行遍歷，判斷取出的cell的字符和我們實體類中的字符是否相符。遍歷得到的list,得到Excel中的cell中的值Object val = this.getCellValue(row, column++); 判斷值的類型，從而轉換成對應的實體類的字段的類型。 3.遍歷導入即可