list集合转csv文件以及servlet导出csv和excel文件

public class CsvToListObjectTest {

    /**
     * 写入csv文件
     * @param list
     * @param fileName
     * @return
     */
    public static File getCsvFile(List<User> list, String fileName){
        File file = new File(fileName);
        FileOutputStream fos = null;
        OutputStreamWriter osw = null;
        BufferedWriter bfw = null;
        try {
            fos = new FileOutputStream(file);
            osw = new OutputStreamWriter(fos);
            bfw = new BufferedWriter(osw);
            bfw.write(list.get(0).getKeyString()+"\r");
            for (int i = 0; i < list.size(); i++) {
                bfw.write(list.get(i).getValueString()+"\r");
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                if (bfw != null){
                    bfw.close();
                }
                if (osw != null){
                    osw.close();
                }
               if (fos != null){
                   fos.close();
               }
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
        return file;
    }



    public static void main(String[] agrs){
        User user = null;
        ArrayList<User> list = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            user = new User();
            user.setUser_id(10000+i);
            user.setUser_name("user"+i);
            user.setUser_age(20+i);
            user.setUser_sex("男");
            user.setUser_pwd("123456"+i);
            user.setUser_phone("123456789"+i);
            user.setUser_type(""+i);
            list.add(user);
        }
        File file = getCsvFile(list,"user.csv");
    }

    /**
     * Servlet导出list集合的csv文件
     * @param response
     * @param list
     * @param fileName
     */
    public static void getCsvFile(HttpServletResponse response, List<User> list, String fileName){
        //设置文件名
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        String fname = fileName+sdf.format(new Date())+".csv";
        //设置response
        response.reset();
        response.setHeader("Content-disposition", "attachment; filename="+fname);
        response.setContentType("application/ms-txt.numberformat:@");
        //获得输出流
        OutputStream os = null;
        OutputStreamWriter osw = null;
        BufferedWriter bfw = null;
        //写入数据
        try {
            os = response.getOutputStream();
            osw = new OutputStreamWriter(os);
            bfw = new BufferedWriter(osw);
            bfw.write(list.get(0).getKeyString()+"\r");
            for (int i = 0; i < list.size(); i++) {
                bfw.write(list.get(i).getValueString()+"\r");
            }
           
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                if (bfw != null){
                    bfw.flush();
                    bfw.close();
                }
                if (osw != null){
                    osw.close();
                }
                if (os != null){
                    os.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

public class User {

    private Integer user_id;

    private String user_name;

    private String user_pwd;

    private Integer user_age;

    private String user_sex;

    private String user_phone;

    private String user_type;


    public String getKeyString() {
        return "user_id,"+"user_name,"+"user_pwd,"+"user_age,"+"user_sex,"+"user_phone,"+"user_type";
    }

    public String getValueString(){
        return user_id+","+user_name+","+user_pwd+","+user_age+","+user_sex+","+user_phone+","+user_type;
    }


    public Integer getUser_id() {
        return user_id;
    }

    public void setUser_id(Integer user_id) {
        this.user_id = user_id;
    }

    public String getUser_name() {
        return user_name;
    }

    public void setUser_name(String user_name) {
        this.user_name = user_name;
    }

    public String getUser_pwd() {
        return user_pwd;
    }

    public void setUser_pwd(String user_pwd) {
        this.user_pwd = user_pwd;
    }

    public Integer getUser_age() {
        return user_age;
    }

    public void setUser_age(Integer user_age) {
        this.user_age = user_age;
    }

    public String getUser_sex() {
        return user_sex;
    }

    public void setUser_sex(String user_sex) {
        this.user_sex = user_sex;
    }

    public String getUser_phone() {
        return user_phone;
    }

    public void setUser_phone(String user_phone) {
        this.user_phone = user_phone;
    }

    public String getUser_type() {
        return user_type;
    }

    public void setUser_type(String user_type) {
        this.user_type = user_type;
    }
}

User类中以及实现了csv头部和值的连接。

使用workbook导出excel:

  /**
     * 导出list集合的excel文件
     */
    public static void excelFile(HttpServletResponse response, List<UserInfo> list, String fileName, String fileType){
        //设置文件名
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        String fname = fileName+sdf.format(new Date())+fileType;
        //设置response
        response.reset();
        response.setHeader("Content-disposition", "attachment; filename="+fname);
        response.setContentType("application/ms-excel.numberformat:@");
        //获得输出流
        OutputStream os = null;
        try {
            os = response.getOutputStream();
            Workbook workbook = null;
            if (fileType.equals(".xlsx")){
                //.xlsx
                workbook = new XSSFWorkbook();
            }else {
                //.xls
                workbook = new HSSFWorkbook();
            }
            Sheet sheet = workbook.createSheet();
            Row rowh = sheet.createRow(0);
            rowh.createCell(0).setCellValue("user_id");
            rowh.createCell(1).setCellValue("user_name");
            rowh.createCell(2).setCellValue("user_age");
            rowh.createCell(3).setCellValue("user_sex");
            rowh.createCell(4).setCellValue("user_phone");
            rowh.createCell(5).setCellValue("user_type");
            for (int i = 1; i < list.size(); i++) {
                Row row = sheet.createRow(i);
                row.createCell(0).setCellValue(list.get(i).getUserId());
                row.createCell(1).setCellValue(list.get(i).getUserName());
                row.createCell(2).setCellValue(list.get(i).getUserAge());
                row.createCell(3).setCellValue(list.get(i).getUserSex());
                row.createCell(4).setCellValue(list.get(i).getUserPhone());
                row.createCell(5).setCellValue(list.get(i).getUserType());
            }
           workbook.write(os);
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if (os != null){
                try {
                    os.flush();
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }