直接上代码：

    public static void main(String[] args) {

        // 设置excel工作簿
        ExcelWriter excelWriter = EasyExcel.write("F:\\excel\\a.xls")
                .build();

        List<User> userList = new ArrayList<>();
        userList.add(new User("lisi", "12"));
        userList.add(new User("wangWu", "15"));
        userList.add(new User("zhaoLiu", "22"));
        ExcelWriterSheetBuilder userExcelSheet = new ExcelWriterSheetBuilder();
        userExcelSheet.sheetName("学生信息");
        userExcelSheet.sheetNo(0);
        excelWriter.write(userList, userExcelSheet.build());


        List<ClassInfo> classInfoList = new ArrayList<>();
        classInfoList.add(new ClassInfo("1班", "22"));
        classInfoList.add(new ClassInfo("2班", "32"));
        ExcelWriterSheetBuilder classExcelSheet = new ExcelWriterSheetBuilder();
        classExcelSheet.sheetName("班级信息");
        classExcelSheet.sheetNo(1);
        excelWriter.write(classInfoList, classExcelSheet.build());

        excelWriter.finish();
    }

注意：
当设置完sheet时最后必须调用finish 方法不然当你打开excel时就会