ssm上传下载 增删改查

SSM是指Spring+SpringMVC+MyBatis，是一个JavaWeb开发框架。下面我将为您介绍SSM框架中的文件上传下载和增删改查操作。

文件上传下载：

1.上传文件

（1）在SpringMVC的配置文件中添加multipartResolver

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/>

（2）在Controller中添加上传文件处理方法

@RequestMapping(value = "/upload", method = RequestMethod.POST)
public String upload(@RequestParam("file") MultipartFile file, HttpServletRequest request) {
    if (!file.isEmpty()) {
        try {
            String fileName = file.getOriginalFilename();
            String filePath = request.getSession().getServletContext().getRealPath("/") + "upload/";
            File dest = new File(filePath + fileName);
            if (!dest.getParentFile().exists()) {
                dest.getParentFile().mkdirs();
            }
            file.transferTo(dest);
            return "success";
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    return "error";
}

2.下载文件

（1）在Controller中添加下载文件处理方法

@RequestMapping(value = "/download", method = RequestMethod.GET)
public void download(HttpServletRequest request, HttpServletResponse response) {
    String fileName = "xxx.jpg"; //文件名
    String filePath = request.getSession().getServletContext().getRealPath("/") + "upload/";
    File file = new File(filePath + fileName);
    if (file.exists()) {
        response.setContentType("application/force-download");
        response.addHeader("Content-Disposition", "attachment;fileName=" + fileName);
        byte[] buffer = new byte[1024];
        FileInputStream fis = null;
        BufferedInputStream bis = null;
        try {
            fis = new FileInputStream(file);
            bis = new BufferedInputStream(fis);
            OutputStream os = response.getOutputStream();
            int i = bis.read(buffer);
            while (i != -1) {
                os.write(buffer, 0, i);
                i = bis.read(buffer);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (bis != null) {
                try {
                    bis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

增删改查：

1.增加数据

（1）在Mapper中添加insert方法

public void insert(User user);

（2）在Service中添加insert方法

public void insert(User user) {
    userMapper.insert(user);
}

（3）在Controller中添加insert处理方法

@RequestMapping(value = "/insert", method = RequestMethod.POST)
public String insert(User user) {
    userService.insert(user);
    return "success";
}

2.删除数据

（1）在Mapper中添加delete方法

public void delete(int id);

（2）在Service中添加delete方法

public void delete(int id) {
    userMapper.delete(id);
}

（3）在Controller中添加delete处理方法

@RequestMapping(value = "/delete", method = RequestMethod.GET)
public String delete(int id) {
    userService.delete(id);
    return "success";
}

3.修改数据

（1）在Mapper中添加update方法

public void update(User user);

（2）在Service中添加update方法

public void update(User user) {
    userMapper.update(user);
}

（3）在Controller中添加update处理方法

@RequestMapping(value = "/update", method = RequestMethod.POST)
public String update(User user) {
    userService.update(user);
    return "success";
}

4.查询数据

（1）在Mapper中添加select方法

public List<User> selectAll();

（2）在Service中添加selectAll方法

public List<User> selectAll() {
    return userMapper.selectAll();
}

（3）在Controller中添加selectAll处理方法

@RequestMapping(value = "/selectAll", method = RequestMethod.GET)
public String selectAll(Model model) {
    List<User> userList = userService.selectAll();
    model.addAttribute("userList", userList);
    return "userList";
}

PS:以上代码仅供参考，具体实现需要根据具体业务需求进行修改。