SpringMVC-FileUpload - 客户端发送的请求在语法上不正确

我见过几个关于同一主题的 qt。但我没有发现这个错误的任何线索。

我正在研究 POC，并点击下面的链接。http://spring.io/guides/gs/uploading-files/

正如上面教程中提到的，在独立模式下[spring embedded Tomcat]它工作得非常好。 但我想将其部署为网络应用程序。因此，我创建了一个单独的 SpringMVC 项目并添加了以下控制器。

控制器文件

@Controller
public class FileUploadController {

    @RequestMapping(value="/upload", method=RequestMethod.GET)
    public @ResponseBody String provideUploadInfo() {
        return "You can upload a file by posting to this same URL.";
    }

    @RequestMapping(value="/upload", method=RequestMethod.POST)
    public @ResponseBody String handleFileUpload(@RequestParam("name") String name, 
            @RequestParam("file") MultipartFile file){
        if (!file.isEmpty()) {
            try {
                byte[] bytes = file.getBytes();
                BufferedOutputStream stream = 
                        new BufferedOutputStream(new FileOutputStream(new File(name + "-uploaded")));
                stream.write(bytes);
                stream.close();
                return "You successfully uploaded " + name + " into " + name + "-uploaded !";
            } catch (Exception e) {
                return "You failed to upload " + name + " => " + e.getMessage();
            }
        } else {
            return "You failed to upload " + name + " because the file was empty.";
        }
    }

}

我编写了以下客户端（因为我不想在这里使用 RestTemplate）。

服务客户

private static final String URL_GET = "http://localhost:8080/SpringMVC/upload";
static String URL = "http://localhost:8080/SpringMVC/upload";

public static void main(String[] args) throws Exception {
    PropertyConfigurator.configure("C:/DevEnvProject/eclipse/workspace_exp/OCR/log4j.properties");
    testGet();
    testPOST();
}

private static void testGet() throws ClientProtocolException, IOException {
    HttpClient httpClient = new DefaultHttpClient();
    HttpContext localContext = new BasicHttpContext();
    HttpGet httpGet = new HttpGet(URL_GET);
    HttpResponse response = httpClient.execute(httpGet, localContext);

    BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8"));
    String sResponse = reader.readLine();

} 

static void testPOST() {
    try {
        HttpClient httpClient = new DefaultHttpClient();
        HttpContext localContext = new BasicHttpContext();
        HttpPost httpPost = new HttpPost(URL);

        MultipartEntity entity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);

        entity.addPart("name", new StringBody("testIcon.png"));
        entity.addPart("file", new FileBody(new File("C:/testIcon.png")));
        httpPost.setEntity(entity);
        HttpResponse response = httpClient.execute(httpPost, localContext);


        BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8"));
        String sResponse = reader.readLine();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

我无法成功调用 POST 端点。每次，我都会遇到以下异常。

400 Bad Request - 客户端发送的请求在语法上不正确

“GET”调用工作正常。我将“POST”请求的日志与我在使用 Spring 教程中提到的独立方法进行测试时收到的相同“POST”请求进行了比较。在请求部分没有发现任何差异。

我知道我在这篇文章中相当冗长。我想提供尽可能多的上下文信息。请帮忙。

Thanks

您需要做两件事：

首先，将 Apache Commons FileUpload 库添加到类路径中。如果使用maven，可以获取依赖here。如果没有，您仍然可以下载 jar 并手动添加。

其次，你必须声明一个MultipartResolver上下文中带有名称的 beanmultipartResolver。通过 Apache Commons FileUpload，您可以使用CommonsMultipartResolver。例如，对于 Java 配置，这将是

@Bean(name = "multipartResolver")
public CommonsMultipartResolver multipartResolver() {
    CommonsMultipartResolver commonsMultipartResolver = new CommonsMultipartResolver(); 
    // set any fields
    return commonsMultipartResolver; 
}

使用 XML 配置，

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

    <!-- set any properties -->
</bean>

这进一步记录在Spring官方文档.