pom包的配置
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>启动项类修改
/**
* 防止文件大于10M时Tomcat连接重置
*
* @return
*/
@Bean
public TomcatServletWebServerFactory tomcatEmbedded() {
TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory();
tomcat.addConnectorCustomizers((TomcatConnectorCustomizer) connector -> {
if ((connector.getProtocolHandler() instanceof AbstractHttp11Protocol<?>)) {
((AbstractHttp11Protocol<?>) connector.getProtocolHandler()).setMaxSwallowSize(-1);
}
});
return tomcat;
}配置文件修改
# 禁用 thymeleaf 缓存
spring.thymeleaf.cache=false
# 是否支持批量上传 (默认值 true)
spring.servlet.multipart.enabled=true
# 上传文件的临时目录 （一般情况下不用特意修改）
spring.servlet.multipart.location=
# 上传文件最大为 1M （默认值 1M 根据自身业务自行控制即可）
spring.servlet.multipart.max-file-size=10MB
# 上传请求最大为 10M（默认值10M 根据自身业务自行控制即可）
spring.servlet.multipart.max-request-size=10MB
# 文件大小阈值，当大于这个阈值时将写入到磁盘，否则存在内存中，（默认值0 一般情况下不用特意修改）
spring.servlet.multipart.file-size-threshold=0
# 判断是否要延迟解析文件（相当于懒加载，一般情况下不用特意修改）
spring.servlet.multipart.resolve-lazily=false
file.upload.path: /file/upload单文件上传
@PostMapping("/upload")
public Map<String, String> upload(@RequestParam MultipartFile file) throws IOException {
//创建本地文件
File localFile = new File(path, file.getOriginalFilename());
//把传上来的文件写到本地文件
file.transferTo(localFile);
//返回localFile文件路径
Map<String, String> path = new HashMap<>();
path.put("path", localFile.getAbsolutePath());
return path;
}这时候系统将会出现FileNotFoundException，日志类似下面这样：
java.io.FileNotFoundException:C:\Users\cheng\AppData\Local\Temp\tomcat.7543349588424487992.9000\work\Tomcat\localhost\ROOT\file\upload\tmp\file\upload\1558332190813.jpg (系统找不到指定的路径。)这是什么原因呢？可以进入transferTo方法
@Override
public void transferTo(File dest) throws IOException, IllegalStateException {
this.part.write(dest.getPath());
if (dest.isAbsolute() && !dest.exists()) {
// Servlet 3.0 Part.write is not guaranteed to support absolute file paths:
// may translate the given path to a relative location within a temp dir
// (e.g. on Jetty whereas Tomcat and Undertow detect absolute paths).
// At least we offloaded the file from memory storage; it'll get deleted
// from the temp dir eventually in any case. And for our user's purposes,
// we can manually copy it to the requested location as a fallback.
FileCopyUtils.copy(this.part.getInputStream(), Files.newOutputStream(dest.toPath()));
}
}而后我们再进入write方法
@Override
public void write(String fileName) throws IOException {
File file = new File(fileName);
if (!file.isAbsolute()) {
file = new File(location, fileName);
}
try {
fileItem.write(file);
} catch (Exception e) {
throw new IOException(e);
}
}这时候我们看到如果file.isAbsolute()成立,也就是我们没有使用绝对路径,那么file = new File(location,fileName);会在原来的基础上加上location路径.这就是原因所在,可以通过修改绝对路径解决
- 直接将file.upload.path修改为绝对路径即可
在代码中控制
@PostMapping("/upload") public Map<String, String> upload(@RequestParam MultipartFile file) throws IOException { //创建本地文件 String classpath = ResourceUtils.getURL("classpath:").getPath(); File localFile = new File(classpath + path, file.getOriginalFilename()); //把传上来的文件写到本地文件 file.transferTo(localFile); //返回localFile文件路径 Map<String, String> path = new HashMap<>(); path.put("path", localFile.getAbsolutePath()); return path; }通过
ResourceUtils.getURL("classpath:").getPath()获得项目路径，然后加上设置的相对路径。网络上还有一种修改
location值的方式，可以看 这篇博客但是我个人使用是一直不可以。或者可以不使用transferTo，代码如下
@PostMapping("/singleFileUpload") public String singleFileUpload(@RequestParam("file") MultipartFile file) throws IOException { byte[] bytes = file.getBytes(); Path filePath = Paths.get(path + file.getOriginalFilename()); Files.write(filePath, bytes); return file.getOriginalFilename(); }Paths.get所使用的也是绝对路径，如果您在Windows机器上使用了这种路径(从/开始的路径)，那么路径将被解释为相对于当前驱动器，例如/file/upload/1.txt而您的项目位于D盘。那么这条路径就会对应这条完整的路径:
D:\file\upload\1.txt
为了简便，以下代码均是使用绝对路径。
文件上传控制器编写
多文件上传
@PostMapping("/uploads")
public Map<String, String> uploads(@RequestParam MultipartFile[] files) throws IOException {
StringBuilder sb = new StringBuilder();
Map<String, String> paths = new HashMap<>();
for (MultipartFile file : files) {
//创建本地文件
File localFile = new File(path, file.getOriginalFilename());
//把传上来的文件写到本地文件
file.transferTo(localFile);
sb.append(localFile.getAbsolutePath()).append(",");
paths.put(file.getOriginalFilename(), localFile.getAbsolutePath());
}
//返回localFile文件路径
return paths;
}多文件上传+表单提交
@PostMapping("/uploadsWithForm")
public Map<String, String> uploadsWithForm(@RequestParam String tmpString, @RequestParam MultipartFile[] files) throws IOException {
StringBuilder sb = new StringBuilder();
Map<String, String> paths = new HashMap<>();
paths.put("tmpString", tmpString);
for (MultipartFile file : files) {
//创建本地文件
File localFile = new File(path, file.getOriginalFilename());
//把传上来的文件写到本地文件
file.transferTo(localFile);
sb.append(localFile.getAbsolutePath()).append(",");
paths.put(file.getOriginalFilename(), localFile.getAbsolutePath());
}
//返回localFile文件路径
return paths;
}多文件上传+Json数据提交
@PostMapping(value = "/uploadsWithJson")
public Map<String, String> uploadsWithJson(@RequestPart("files") MultipartFile[] files, @RequestPart("jsonMap") Map<String, Object> jsonMap) throws IOException {
StringBuilder sb = new StringBuilder();
Map<String, String> paths = new HashMap<>();
System.out.println(jsonMap);
for (MultipartFile file : files) {
//创建本地文件
File localFile = new File(path, file.getOriginalFilename());
//把传上来的文件写到本地文件
file.transferTo(localFile);
sb.append(localFile.getAbsolutePath()).append(",");
paths.put(file.getOriginalFilename(), localFile.getAbsolutePath());
}
paths.put("jsonMap", JsonUtils.obj2json(jsonMap));
//返回localFile文件路径
return paths;
}呵呵，不好用对不对。项目抛出了个异常，HttpMediaTypeNotSupportedException。
WARN o.s.w.s.m.support.DefaultHandlerExceptionResolver - Resolved [org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'application/octet-stream' not supported]所以我们需要添加个转换器类
@Component
public class MultipartJackson2HttpMessageConverter extends AbstractJackson2HttpMessageConverter {
/**
* Converter for support http request with header Content-Type: multipart/form-data
*/
public MultipartJackson2HttpMessageConverter(ObjectMapper objectMapper) {
super(objectMapper, MediaType.APPLICATION_OCTET_STREAM);
}
@Override
public boolean canWrite(Class<?> clazz, MediaType mediaType) {
return false;
}
@Override
public boolean canWrite(Type type, Class<?> clazz, MediaType mediaType) {
return false;
}
@Override
protected boolean canWrite(MediaType mediaType) {
return false;
}
}这样就能够识别了
总结
感觉把springboot文件上传所能遇到的坑全踩了个变，心累。
如果需要项目代码，可以去我的github中下载；具体代码可以查看file.upload目录
