JAVA文件上传基本操作 最近在学习文件上传部署的一些操作,以此记录做备忘之用.一共两种方式:1> 标准上传方式,可通过form表单action属性请求或者ajax方式进行请求,返回服务器上的存储路径.2> 在前端将文件转换为Base64,然后将文件名和Base64字符串后端,经过解析之后,以输出流的方式写入到指定文件路径之中.项目绝对路径基本可通过servletContext和类加载器.getPath的方式得到,不做赘述.获取项目绝对路径://类加载器方式 ClassLoader classLoader = this.getClass().getClassLoader(); URL resource = classLoader.getResource("."); String path = resource.getPath(); //通过ServletContext ServletContext servletContext = request.getServletContext(); String realPath = servletContext.getRealPath("");<!--文件上传导包--> <!-- https://mvnrepository.com/artifact/commons-fileupload/commons-fileupload --> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.1<ersion> </dependency> <!-- https://mvnrepository.com/artifact/commons-io/commons-io --> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.5<ersion> </dependency>两种文件上传方式: import com.alibaba.fastjson.JSON; import com.sakura.Common.ResponseCode; import com.sakura.Common.ServerResponse; import com.sakura.Const.Const; import com.sakura.Pojo.User; import com.sakura.Utils.Random; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; import org.springframework.stereotype.Service; import javax.servlet.ServletContext; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import java.io.*; import java.util.ArrayList; import java.util.Base64; import java.util.List; @Service public class UploadFileService { // 上传配置 private static final int MEMORY_THRESHOLD = 1024 * 1024 * 3; // 3MB private static final int MAX_FILE_SIZE = 1024 * 1024 * 40; // 40MB private static final int MAX_REQUEST_SIZE = 1024 * 1024 * 50; // 50MB private ResponseCode data=new ResponseCode(); //基本文件上传 public ServerResponse loadFile(HttpSession session, HttpServletRequest request, HttpServletResponse response) { try { request.setCharacterEncoding("UTF-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } response.setContentType("textml;charset=UTF-8"); // 检测是否为多媒体上传 if (!ServletFileUpload.isMultipartContent(request)) { // 如果不是则停止 PrintWriter writer = null; try { writer = response.getWriter(); } catch (IOException e) { e.printStackTrace(); } writer.println("Error: 表单必须包含 enctype=multipart/form-data"); writer.flush(); return ServerResponse.DefaultResponse(Const.OPERATION_DEFAULE, Const.DEFAULT_FILE); } // 配置上传参数 DiskFileItemFactory factory = new DiskFileItemFactory(); // 设置内存临界值 - 超过后将产生临时文件并存储于临时目录中 factory.setSizeThreshold(MEMORY_THRESHOLD); // 设置临时存储目录 factory.setRepository(new File(System.getProperty("java.io.tmpdir"))); ServletFileUpload upload = new ServletFileUpload(factory); // 设置最大文件上传值 upload.setFileSizeMax(MAX_FILE_SIZE); // 设置最大请求值 (包含文件和表单数据) upload.setSizeMax(MAX_REQUEST_SIZE); // 中文处理 upload.setHeaderEncoding("UTF-8"); // 构造临时路径来存储上传的文件 // 这个路径相对当前应用的目录 String UPLOAD_DIRECTORY = "upload"; //存储文件目录 ServletContext servletContext = request.getServletContext(); String realPath = servletContext.getRealPath(""); String uploadPath = realPath + File.separator + UPLOAD_DIRECTORY; System.out.println("uploadPath:" + uploadPath); // 如果目录不存在则创建 File uploadDir = new File(uploadPath); if (!uploadDir.exists()) { uploadDir.mkdir(); } try { // 解析请求的内容提取文件数据 @SuppressWarnings("unchecked") List<FileItem> formItems = upload.parseRequest(request); if (formItems != null && formItems.size() > 0) { int size = formItems.size(); List<String> UrlList = new ArrayList(); // 迭代表单数据 for (FileItem item : formItems) { // 处理不在表单中的字段 if (!item.isFormField()) { String fileName = new File(item.getName()).getName(); //时间 UUID随机串以避免重复 String uuid =Random.RandUUIDAndDate()+"_"+fileName; String filePath = uploadPath + File.separator + uuid; File storeFile = new File(filePath); // 在控制台输出文件的上传路径 System.out.println("filePath:" + filePath); // 保存文件到硬盘 item.write(storeFile); UrlList.add(UPLOAD_DIRECTORY + "/" + uuid); } } data.setMsg(JSON.toJSONString(UrlList)); data.setStatus(200); } } catch (Exception ex) { String error = "错误信息: " + ex.getMessage(); data.setMsg(error); data.setStatus(100); } return ServerResponse.SuccessResponse(data); } /** * Base64方式存储文件 此法不通 需配置tomcat文件 同时Base64解码会出错,待研 * 究,不可用! * @param name * @param base64String * @param session * @param request * @param response * @return */ public ServerResponse loadFileBase64(String name, String base64String, HttpSession session, HttpServletRequest request, HttpServletResponse response) { ServerResponse res=null; String UPLOAD_DIRECTORY = "upload"; byte[] decode = Base64.getDecoder().decode(base64String); //存储文件目录 ServletContext servletContext = request.getServletContext(); String realPath = servletContext.getRealPath(""); String uploadPath = realPath + File.separator + UPLOAD_DIRECTORY + File.separator + Random.RandUUIDAndDate() +"_"+name; String path=File.separator + UPLOAD_DIRECTORY + File.separator +Random.RandUUIDAndDate()+"_"+name; File file = new File(uploadPath); FileOutputStream fileOutputStream =null; BufferedOutputStream bufferedOutputStream =null; try { fileOutputStream = new FileOutputStream(file); bufferedOutputStream = new BufferedOutputStream(fileOutputStream); bufferedOutputStream.write(decode); bufferedOutputStream.flush(); res.setMsg("上传成功"); res.setStatus(200); res.setData(path); } catch (IOException e) { res.setMsg("上传失败"); res.setStatus(100); path=null; } finally { if (bufferedOutputStream != null) { try { bufferedOutputStream.close(); } catch (IOException e) { e.printStackTrace(); } } if (fileOutputStream != null) { try { fileOutputStream.close(); } catch (IOException e) { e.printStackTrace(); } } } return res; } }

分页插件PageHelper使用 本文使用PageHelper物理分页插件,因为需要在项目中使用分页功能,在此记录做备忘之用GitHub基本文档以作参考.maven导入:<dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper</artifactId> <version>latest version</version> </dependency>1.配置sqlSessionFactory:<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <!-- other configuration --> <property name="plugins"> <array> <bean class="com.github.pagehelper.PageInterceptor"> <property name="properties" value="mysql"/> </bean> </array> </property> </bean>2.使用pageInfo方式://获取第1页，10条内容，默认查询总数count PageHelper.startPage(1, 10); List<User> list = userMapper.selectAll(); //用PageInfo对结果进行包装 PageInfo page = new PageInfo(list);