Spring框架实现文件上传功能
在Java中实现文件的上传有多种方式,如smartUpload或是使用Strus2,本文与大家分享使用Spring框架中的MultipartFile类来实例文件的上传。
不啰嗦了,直接上干货。先是编写了一个实现文件上传的类FileUploadingUtil,此类中定义了两个对外公开的方法,upload和getFileMap。
前者需要传入一个Map参数,是用户提交的表单中的文件列表,最终返回值的也是一个Map类型对象,其键名为上传的文件名称,键值为文件在服务器上的存储路径;后者主要是用于测试用途,非主要功能,看官可以忽略此方法。
package com.emerson.cwms.utils;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import org.springframework.web.multipart.MultipartFile;
/**
* 文件上传工具类
*
* @author Chris Mao(Zibing)
*
*/
public class FileUploadingUtil {
/**
* 服务器上的保存路径,在使用到上传功能的Controller中对其进行赋值
*/
public static String FILEDIR = null;
/**
* 上传多个文件,返回文件名称和服务器存储路径列表
*
* @param files
* @return
* @throws IOException
*/
public static Map<String, String> upload(Map<String, MultipartFile> files) throws IOException {
File file = new File(FILEDIR);
if (!file.exists()) {
file.mkdir();
}
Map<String, String> result = new HashMap<String, String>();
Iterator<Entry<String, MultipartFile>> iter = files.entrySet().iterator();
while (iter.hasNext()) {
MultipartFile aFile = iter.next().getValue();
if (aFile.getSize() != 0 && !"".equals(aFile.getName())) {
result.put(aFile.getOriginalFilename(), uploadFile(aFile));
}
}
return result;
}
/**
* 上传单个文件,并返回其在服务器中的存储路径
*
* @param aFile
* @return
* @throws FileNotFoundException
* @throws IOException
*/
private static String uploadFile(MultipartFile aFile) throws IOException {
String filePath = initFilePath(aFile.getOriginalFilename());
try {
write(aFile.getInputStream(), new FileOutputStream(filePath));
} catch (FileNotFoundException e) {
logger.error("上传的文件: " + aFile.getName() + " 不存在!!");
e.printStackTrace();
}
return filePath;
}
/**
* 写入数据
*
* @param in
* @param out
* @throws IOException
*/
private static void write(InputStream in, OutputStream out) throws IOException {
try {
byte[] buffer = new byte[1024];
int bytesRead = -1;
while ((bytesRead = in.read(buffer)) != -1) {
out.write(buffer, 0, bytesRead);
}
out.flush();
} finally {
try {
in.close();
out.close();
} catch (IOException ex) {
}
}
}
/**
* 遍历服务器目录,列举出目录中的所有文件(含子目录)
* @return
*/
public static Map<String, String> getFileMap() {
logger.info(FileUploadingUtil.FILEDIR);
Map<String, String> map = new HashMap<String, String>();
File[] files = new File(FileUploadingUtil.FILEDIR).listFiles();
if (files != null) {
for (File file : files) {
if (file.isDirectory()) {
File[] files2 = file.listFiles();
if (files2 != null) {
for (File file2 : files2) {
String name = file2.getName();
logger.info(file2.getParentFile().getAbsolutePath());
logger.info(file2.getAbsolutePath());
map.put(file2.getParentFile().getName() + "/" + name,
name.substring(name.lastIndexOf("_") + 1));
}
}
}
}
}
return map;
}
/**
* 返回文件存储路径,为防止重名文件被覆盖,在文件名称中增加了随机数
* @param name
* @return
*/
private static String initFilePath(String name) {
String dir = getFileDir(name) + "";
File file = new File(FILEDIR + dir);
if (!file.exists()) {
file.mkdir();
}
Long num = new Date().getTime();
Double d = Math.random() * num;
return (file.getPath() + "/" + num + d.longValue() + "_" + name).replaceAll(" ", "-");
}
/**
*
* @param name
* @return
*/
private static int getFileDir(String name) {
return name.hashCode() & 0xf;
}
}
Controller代码,使用上述定义的FileUploadingUtil类实现文件上传之功能。
package com.emerson.cwms.web;
import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import com.emerson.cwms.utils.FileUploadingUtil;
/**
* 文件上传控制器
*
* @author Chris Mao(Zibing)
*
*/
@Controller
@RequestMapping(value = "/files")
public class FileController {
@RequestMapping(value = "/", method = RequestMethod.GET)
public String list(HttpServletRequest request, HttpServletResponse response, Model model) {
iniFileDir(request);
System.out.println(request.getAttribute("files"));
model.addAttribute("files", FileUploadingUtil.getFileMap());
return "files/list";
}
@RequestMapping(value = "/upload", method = RequestMethod.POST)
public String doUpload(HttpServletRequest request) {
iniFileDir(request);
try {
MultipartHttpServletRequest mRequest = (MultipartHttpServletRequest) request;
Map<String, String> uploadedFiles = FileUploadingUtil.upload(mRequest.getFileMap());
Iterator<Entry<String, String>> iter = uploadedFiles.entrySet().iterator();
while (iter.hasNext()) {
Entry<String, String> each = iter.next();
System.out.print("Uploaded File Name = " + each.getKey());
System.out.println(", Saved Path in Server = " + each.getValue());
}
} catch (Exception e) {
e.printStackTrace();
}
return "redirect:/files/";
}
private void iniFileDir(HttpServletRequest request) {
FileUploadingUtil.FILEDIR = request.getSession().getServletContext().getRealPath("/") + "files/";
if (FileUploadingUtil.FILEDIR == null) {
FileUploadingUtil.FILEDIR = request.getSession().getServletContext().getRealPath("/") + "files/";
}
}
}
注意事项:一定要在pom.xml文件中添加对commons-fileupload的依赖引用,否则代码在运行时会提示找不到FileItemFactory类的错误。
依赖引用如下。
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.3.1</version>
</dependency>
以上是 Spring框架实现文件上传功能 的全部内容, 来源链接: utcz.com/z/313585.html