这是一个很简单的处理重复导入的方法，但是速度比较慢，我想除了这个方法之外应该也可以用sql语句来对他进行处理吧！

我这里是对导入数据库的每一条记录和数据库里面相关的所有记录进行比较，只要存在相同的记录就不导入，如果没有相同的就插入新的记录！

以下是我的代码：

//导入数据库    public String intoDB() throws IOException{        HttpServletRequest request = ServletActionContext.getRequest();        HttpSession session = request.getSession();        String path = ServletActionContext.getServletContext().getRealPath(        "/general");        String fileName = null;        while(fileName == null){            fileName = (String) session.getAttribute("fileName");        }        File f = new File(path + "/" + fileName);        try {            //用jxl解析excel2003            if(this.getFileFileName()!=null && this.getFileFileName().indexOf(".xlsx")==-1){                Workbook book = Workbook.getWorkbook(f);//                  Sheet sheet = book.getSheet(0); // 获得第一个工作表对象                for (int i = 1; i < sheet.getRows(); i++) {                    BoatTable boat = new BoatTable();                    boat.setBenglishname(sheet.getCell(0, i).getContents());                    boat.setBchinesename(sheet.getCell(1, i).getContents());                    boat.setBregist(sheet.getCell(2, i).getContents());                    boat.setBboat(sheet.getCell(3, i).getContents());                    boat.setBrecongnize(sheet.getCell(4, i).getContents());                    boat.setBmaterial(sheet.getCell(5, i).getContents());                    boat.setBlength(Double.parseDouble(sheet.getCell(6, i).getContents()));                    boat.setBwidth(Double.parseDouble(sheet.getCell(7, i).getContents()));                    boat.setBdeep(Double.parseDouble(sheet.getCell(8, i).getContents()));                    boat.setBsum(Integer.parseInt(sheet.getCell(9, i).getContents()));                    boat.setBsulttle(Integer.parseInt(sheet.getCell(10, i).getContents()));                    boat.setBgross(Integer.parseInt(sheet.getCell(11, i).getContents()));                    boat.setBpower(Integer.parseInt(sheet.getCell(12, i).getContents()));                    boat.setBlog(sheet.getCell(13, i).getContents());                    boat.setBremark(sheet.getCell(14, i).getContents());                    boat.setBcheck(sheet.getCell(15, i).getContents());                    boat.setBwater(sheet.getCell(16, i).getContents());                    boat.setBoperat(sheet.getCell(17, i).getContents());                    boat.setBrange(sheet.getCell(18, i).getContents());                    boat.setBkind(sheet.getCell(19, i).getContents());                    boat.setBowner(sheet.getCell(20, i).getContents());                    //添加到数据库,处理重复提交                    List
     
       bList=boatService.propertyBoat("bchinesename", boat.getBchinesename());                    boolean flag = false;                    for (BoatTable blist : bList) {                        if(!blist.getBboat().equals(boat.getBboat()) || !blist.getBcheck().equals(boat.getBcheck()) || !blist.getBchinesename().equals(boat.getBchinesename())                                || !blist.getBdeep().equals(boat.getBdeep()) || !blist.getBenglishname().equals(boat.getBenglishname()) || !blist.getBgross().equals(boat.getBgross())                                || !blist.getBkind().equals(boat.getBkind()) || !blist.getBlength().equals(boat.getBlength()) || !blist.getBlog().equals(boat.getBlog())                                || !blist.getBmaterial().equals(boat.getBmaterial()) || !blist.getBoperat().equals(boat.getBoperat()) || !blist.getBowner().equals(boat.getBowner())                                || !blist.getBpower().equals(boat.getBpower()) || !blist.getBrange().equals(boat.getBrange()) || !blist.getBrecongnize().equals(boat.getBrecongnize())                                || !blist.getBregist().equals(boat.getBregist()) || !blist.getBremark().equals(boat.getBremark()) || !blist.getBsulttle().equals(boat.getBsulttle())                                || !blist.getBsum().equals(boat.getBsum()) || !blist.getBwater().equals(boat.getBwater()) || !blist.getBwidth().equals(boat.getBwidth())){                            flag = false;                        }else{                            flag = true;                            break;                        }                    }                    if(!flag){                        boatService.addOneBoat(boat);                    }                }            }else{ //用poi解析excel2007                // 构建1个工作簿对象                XSSFWorkbook xwb = null;                try {                    xwb = new XSSFWorkbook(new FileInputStream(f.getPath()));                } catch (Exception e) {                    e.printStackTrace();                }                //得到第一张工作表                XSSFSheet xSheet = xwb.getSheetAt(0);                //循环工作表的每一行                for (int rowNum = 1; rowNum <= xSheet.getLastRowNum(); rowNum++) {                    XSSFRow xRow = xSheet.getRow(rowNum);                    if (xRow == null) {                        continue;                    }                    BoatTable boat = new BoatTable();                    boat.setBenglishname(xRow.getCell(0).getStringCellValue());                    boat.setBchinesename(xRow.getCell(1).getStringCellValue());                    boat.setBregist(xRow.getCell(2).getStringCellValue());                    if(xRow.getCell(3).getCellType() == XSSFCell.CELL_TYPE_NUMERIC){                        boat.setBboat(Double.valueOf(xRow.getCell(3).getNumericCellValue()).toString());                    }else{                        boat.setBboat(xRow.getCell(3).getStringCellValue());                    }                    boat.setBrecongnize(xRow.getCell(4).getStringCellValue());                    boat.setBmaterial(xRow.getCell(5).getStringCellValue());                    boat.setBlength(xRow.getCell(6).getNumericCellValue());                    boat.setBwidth(xRow.getCell(7).getNumericCellValue());                    boat.setBdeep(xRow.getCell(8).getNumericCellValue());                    boat.setBsum((int)xRow.getCell(9).getNumericCellValue());                    boat.setBsulttle((int)xRow.getCell(10).getNumericCellValue());                    boat.setBgross((int)xRow.getCell(11).getNumericCellValue());                    boat.setBpower((int)xRow.getCell(12).getNumericCellValue());                    boat.setBlog(xRow.getCell(13).getStringCellValue());                    boat.setBremark(xRow.getCell(14).getStringCellValue());                    //如果单元格里面为数字，用String取得话会报异常，故有可能为数字的都要判断一下                    if(xRow.getCell(15).getCellType() == XSSFCell.CELL_TYPE_NUMERIC){                        boat.setBcheck(Double.valueOf(xRow.getCell(15).getNumericCellValue()).toString());                    }else{                        boat.setBcheck(xRow.getCell(15).getStringCellValue());                    }                    if(xRow.getCell(16).getCellType() == XSSFCell.CELL_TYPE_NUMERIC){                        boat.setBwater(Double.valueOf(xRow.getCell(16).getNumericCellValue()).toString());                    }else{                        boat.setBwater(xRow.getCell(16).getStringCellValue());                    }                    if(xRow.getCell(17).getCellType() == XSSFCell.CELL_TYPE_NUMERIC){                        boat.setBoperat(Double.valueOf(xRow.getCell(17).getNumericCellValue()).toString());                    }else{                        boat.setBoperat(xRow.getCell(17).getStringCellValue());                    }                    boat.setBrange(xRow.getCell(18).getStringCellValue());                    boat.setBkind(xRow.getCell(19).getStringCellValue());                    boat.setBowner(xRow.getCell(20).getStringCellValue());                    //添加到数据库                    List
      
        bList=boatService.propertyBoat("bchinesename", boat.getBchinesename());                    boolean flag = false;                    for (BoatTable blist : bList) {                        if(!blist.getBboat().equals(boat.getBboat()) || !blist.getBcheck().equals(boat.getBcheck()) || !blist.getBchinesename().equals(boat.getBchinesename())                                || !blist.getBdeep().equals(boat.getBdeep()) || !blist.getBenglishname().equals(boat.getBenglishname()) || !blist.getBgross().equals(boat.getBgross())                                || !blist.getBkind().equals(boat.getBkind()) || !blist.getBlength().equals(boat.getBlength()) || !blist.getBlog().equals(boat.getBlog())                                || !blist.getBmaterial().equals(boat.getBmaterial()) || !blist.getBoperat().equals(boat.getBoperat()) || !blist.getBowner().equals(boat.getBowner())                                || !blist.getBpower().equals(boat.getBpower()) || !blist.getBrange().equals(boat.getBrange()) || !blist.getBrecongnize().equals(boat.getBrecongnize())                                || !blist.getBregist().equals(boat.getBregist()) || !blist.getBremark().equals(boat.getBremark()) || !blist.getBsulttle().equals(boat.getBsulttle())                                || !blist.getBsum().equals(boat.getBsum()) || !blist.getBwater().equals(boat.getBwater()) || !blist.getBwidth().equals(boat.getBwidth())){                            flag = false;                        }else{                            flag = true;                            break;                        }                    }                    if(!flag){                        boatService.addOneBoat(boat);                    }                }            }        } catch (BiffException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }         f.delete();        session.removeAttribute("fileName");        return null;    }