springMVC之单文件上传

springmvc对form表单的支持已经很成熟，仅仅两步：

配置支持文件上传的bean：org.springframework.web.multipart.commons.CommonsMultipartResolver



同时设置文件编码、单次提交表单上传文件最大字节数、以及写文件时使用的缓冲区大小

开发处理：handler[org.hy.ssm.web.controller.FormController.uploadOne(MultipartFile)]

Java代码


/**

* @Title: uploadOne

* @Description: 单文件上传

* @param file

* @return ModelMap

*/

@RequestMapping("/uploadOne")

@ResponseBody

public ModelMap uploadOne(MultipartFile file) {

final String UPLOAD_DIR = "/upload/";

final String KEY_OF_ORIGINAL_FILE_NAME = "origFileName";

final String KEY_OF_FILE_URL = "fileUrl";

final String KEY_OF_FILE_SUFFIX = "fileSuffix";

boolean flag = false;

String message = null;

Map<String, String> data = Maps.newHashMap();

// 原文件名(通常用于下载展示)

String originalFilename = file.getOriginalFilename();

data.put(KEY_OF_ORIGINAL_FILE_NAME, originalFilename);

// 文件类型(后缀)

String suffix = FileUtil.getSuffix(originalFilename);

data.put(KEY_OF_FILE_SUFFIX, suffix);

// 目标文件名(通常情况需要重命名, 防止同名文件覆盖)

String fileName = String.valueOf(System.currentTimeMillis()) + suffix;

String fileUrl = (UPLOAD_DIR + fileName);

data.put(KEY_OF_FILE_URL, fileUrl);

try {

File dest = WebUtil.getFile(fileUrl);

file.transferTo(dest);

flag = true;

} catch (Exception e) {

flag = false;

message = "";

LOGGER.warn(message + " : " + e.getMessage(), e);

}

return WebUtil.getModelMap(flag, data, message);

}

接下来验证结果是否正确：



正常验证





非法验证，文件大小超出。当前测试数据70+MB

Java代码


org.springframework.web.multipart.MaxUploadSizeExceededException: Maximum upload size of 32505856 bytes exceeded; nested exception is org.apache.commons.fileupload.FileUploadBase$SizeLimitExceededException: the request was rejected because its size (79882924) exceeds the configured maximum (32505856)

at org.springframework.web.multipart.commons.CommonsMultipartResolver.parseRequest(CommonsMultipartResolver.java:160)

at org.springframework.web.multipart.commons.CommonsMultipartResolver.resolveMultipart(CommonsMultipartResolver.java:139)

at org.springframework.web.servlet.DispatcherServlet.checkMultipart(DispatcherServlet.java:1020)

at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:883)

at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)

at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)

at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)

at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:504)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)

at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421)

at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1074)

at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)

at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)

at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)

at java.lang.Thread.run(Thread.java:722)

Caused by: org.apache.commons.fileupload.FileUploadBase$SizeLimitExceededException: the request was rejected because its size (79882924) exceeds the configured maximum (32505856)

at org.apache.commons.fileupload.FileUploadBase$FileItemIteratorImpl.<init>(FileUploadBase.java:937)

at org.apache.commons.fileupload.FileUploadBase.getItemIterator(FileUploadBase.java:331)

at org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:351)

at org.apache.commons.fileupload.servlet.ServletFileUpload.parseRequest(ServletFileUpload.java:126)

at org.springframework.web.multipart.commons.CommonsMultipartResolver.parseRequest(CommonsMultipartResolver.java:156)

... 28 more

由错误也可定位出，#multipartResolver.maxUploadSize 是用来定位单次表单提交时，文件的限定大小

到此，单文件上传已经搞定。是不是很简单呢？当然了还有稍微原始的方法，通过 org.apache.commons.fileupload.servlet.ServletFileUpload 也能实现文件上传的功能，在此不做详解。大致步骤如下：

获取工厂 DiskFileItemFactory

通过工厂获取上传组件 ServletFileUpload

解析请求获取表单项

判断表单项类型

解析表单项

Java代码


/**

* @Title: uploadByFileUpload

* @Description: 使用Commons.FileUpload上传文件

*/

@RequestMapping("/uploadByFileUpload")

public void uploadByFileUpload() {

final String UPLOAD_DIR = "upload/";

final String basePath = WebUtil.getBaseFilPath();

HttpServletRequest request = WebUtil.getRequest();

try {

// 防止中文名乱码

request.setCharacterEncoding("utf-8");

// 1. 获取工厂 DiskFileItemFactory

DiskFileItemFactory fileItemFactory = new DiskFileItemFactory();

// 缓存区目录

fileItemFactory.setRepository(new File(basePath + "tmp/"));

// 缓存区大小

fileItemFactory.setSizeThreshold(1024 * 6);

// 2. 通过工厂获取上传组件 ServletFileUpload

ServletFileUpload servletFileUpload = new ServletFileUpload(fileItemFactory);

// 设置文件的大小为2M

servletFileUpload.setSizeMax(1024 * 1024 * 2);

// 防止中文乱码(文件名)

servletFileUpload.setHeaderEncoding("UTF-8");

// 3. 解析请求获取表单项

@SuppressWarnings("unchecked")

List<FileItem> items = servletFileUpload.parseRequest(request);

// 4. 判断表单项类型

for (FileItem item : items) {

// 5. 解析表单项

// 表单项名称

String fieldName = item.getFieldName();

if (item.isFormField()) {

// 普通表单项处理

String name = fieldName;

String value = item.getString("UTF-8");

System.out.println(name + ":" + value);

} else {

// 文件表单项

// 获取文件名

String originalFileName = item.getName();

String suffix = FileUtil.getSuffix(originalFileName);

String newFileName = String.valueOf(System.currentTimeMillis());

// 写入文件

String fileName = File.separator + newFileName + suffix;

File newFile = FileUtil.createQuietly(basePath + UPLOAD_DIR + fileName);

item.write(newFile);

item.delete();

}

}

} catch (Exception e) {

LOGGER.warn(e.getMessage(), e);

}

}

注意：如果使用上面的方式获取上传文件，需要停止 springmvc 的文件解析机制，否则将不能获取数据 ！！







源码下载：ssmFU.zip