SpringMVC-FileUpload-客户端发送的请求在语法上不正确

Question

我在同一个主题上看过几个qts。但是我没有发现此错误的任何线索。

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

如以上教程中所述，在独立模式下（春季嵌入式Tomcat），它可以正常工作。但是我想将其部署为Web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.";
        }
    }

}

我已经编写了以下客户端（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错误的请求-客户端发送的请求在语法上不正确

‘GET’通话正常。我将“ POST”请求的日志与我在春季教程中提到的使用独立方法进行测试时得到的“
POST”请求的日志进行了比较。在请求部分未找到任何差异。

我知道我在这篇文章中很冗长。我想提供尽可能多的上下文信息。请帮忙。

谢谢

Answer 1

您需要做两件事：

首先，将Apache Commons
FileUpload库添加到您的类路径。如果使用maven，则可以在此处获取依赖项。如果没有，您仍然可以下载jar并手动添加。

其次，您必须MultipartResolver在上下文中使用name 声明一个bean multipartResolver。通过Apache
Commonds FileUpload，您可以使用CommonsMultipartResolver。例如，使用Java配置，那将是

@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>

在Spring官方文档中有进一步的记录。