利用Java怎么将excel表格转换成json数据

package org.duang.test;import java.io.File;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import net.sf.json.JSONArray;import org.apache.poi.ss.usermodel.Cell;import org.apache.poi.ss.usermodel.DateUtil;import org.apache.poi.ss.usermodel.FormulaEvaluator;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.ss.usermodel.WorkbookFactory;public class Excel2JSONHelper {  //常亮，用作第一种模板类型，如下图  private static final int HEADER_VALUE_TYPE_Z=1;  //第二种模板类型，如下图  private static final int HEADER_VALUE_TYPE_S=2;  public static void main(String[] args) {     File dir = new File("e:\\2003.xls");     Excel2JSONHelper excelHelper = getExcel2JSONHelper();     //dir文件，0代表是第一行为保存到数据库或者实体类的表头，一般为英文的字符串，2代表是第二种模板，      JSONArray jsonArray = excelHelper.readExcle(dir, 0, 2);     System.out.println(jsonArray.toString());;  }    private static Excel2JSONHelper getExcel2JSONHelper(){    return new Excel2JSONHelper();  }    private boolean fileNameFileter(File file){    boolean endsWith = false;    if(file != null){      String fileName = file.getName();      endsWith = fileName.endsWith(".xls") || fileName.endsWith(".xlsx");    }    return endsWith;  }    private Row getHeaderRow(Sheet sheet, int index){    Row headerRow = null;    if(sheet!=null){      headerRow = sheet.getRow(index);    }    return headerRow;  }    private Object getCellValue(Row row,int cellIndex,FormulaEvaluator formula){    Cell cell = row.getCell(cellIndex);    if(cell != null){      switch (cell.getCellType()) {      //String类型      case Cell.CELL_TYPE_STRING:        return cell.getRichStringCellValue().getString();       //number类型      case Cell.CELL_TYPE_NUMERIC:        if (DateUtil.isCellDateFormatted(cell)) {          return cell.getDateCellValue().getTime();        } else {          return cell.getNumericCellValue();        }      //boolean类型      case Cell.CELL_TYPE_BOOLEAN:        return cell.getBooleanCellValue();      //公式        case Cell.CELL_TYPE_FORMULA:        return formula.evaluate(cell).getNumberValue();      default:        return null;      }    }    return null;  }    private String getHeaderCellValue(Row headerRow,int cellIndex,int type){    Cell cell = headerRow.getCell(cellIndex);    String headerValue = null;    if(cell != null){      //第一种模板类型      if(type == HEADER_VALUE_TYPE_Z){        headerValue = cell.getRichStringCellValue().getString();        int l_bracket = headerValue.indexOf("（");        int r_bracket = headerValue.indexOf("）");        if(l_bracket == -1){          l_bracket = headerValue.indexOf("(");        }        if(r_bracket == -1){          r_bracket = headerValue.indexOf(")");        }        headerValue = headerValue.substring(l_bracket+1, r_bracket);      }else if(type == HEADER_VALUE_TYPE_S){      //第二种模板类型        headerValue = cell.getRichStringCellValue().getString();      }    }    return headerValue;  }    public JSONArray readExcle(File file,int headerIndex,int headType){    List<Map<String, Object>> lists = new ArrayList<Map<String, Object>>();    if(!fileNameFileter(file)){      return null;    }else{      try {        //加载excel表格        WorkbookFactory wbFactory = new WorkbookFactory();        Workbook wb = wbFactory.create(file);        //读取第一个sheet页        Sheet sheet = wb.getSheetAt(0);         //读取表头行        Row headerRow = getHeaderRow(sheet, headerIndex);        //读取数据        FormulaEvaluator formula = wb.getCreationHelper().createFormulaEvaluator();        for(int r = headerIndex+1; r<= sheet.getLastRowNum();r++){          Row dataRow = sheet.getRow(r);          Map<String, Object> map = new HashMap<String, Object>();          for(int h = 0; h<dataRow.getLastCellNum();h++){            //表头为key            String key = getHeaderCellValue(headerRow,h,headType);            //数据为value            Object value = getCellValue(dataRow, h, formula);            if(!key.equals("") && !key.equals("null") && key != null ){              map.put(key, value);            }          }          lists.add(map);        }      } catch (Exception e) {        e.printStackTrace();      }     }    JSONArray jsonArray = JSONArray.fromObject(lists);    return jsonArray;  }}