java - JERSEY 使用 jquery/AJAX 上传文件

Question

我想通过 jquery/AJAX 上传带有 Jersey 的文件，但我不知道如何从输入中获取文件并使用 ajax 发送它。

到目前为止，这是我的代码:

html

<form action="rest/files/upload" method="post" enctype="multipart/form-data">

   <p>
    Select a file : <input type="file" name="file" size="50" />
   </p>

   <input type="submit" value="Upload It" />
</form>

JAVA

    @POST
@Path("/upload")
@Consumes(MediaType.MULTIPART_FORM_DATA)
public Response uploadFile(
        @FormDataParam("file") InputStream fileInputStream,
        @FormDataParam("file") FormDataContentDisposition contentDispositionHeader) {

    String filePath = SERVER_UPLOAD_LOCATION_FOLDER + contentDispositionHeader.getFileName();

    // save the file to the server
    saveFile(fileInputStream, filePath);

    String output = "File saved to server location : " + filePath;

    return Response.status(200).entity(output).build();

}

// save uploaded file to a defined location on the server
private void saveFile(InputStream uploadedInputStream,
        String serverLocation) {

    try {
        OutputStream outpuStream = new FileOutputStream(new File(serverLocation));
        int read = 0;
        byte[] bytes = new byte[1024];

        outpuStream = new FileOutputStream(new File(serverLocation));
        while ((read = uploadedInputStream.read(bytes)) != -1) {
            outpuStream.write(bytes, 0, read);
        }
        outpuStream.flush();
        outpuStream.close();
    } catch (IOException e) {

        e.printStackTrace();
    }

}

该代码与正常的 html 提交一起工作。

我用了这个例子:jersey file upload

这是我目前的方法

var file = $('input[name="file"').get(0).files[0];

          var formData = new FormData();
          formData.append('file', file);

          $.ajax({
                url : '/OIS/rest/upload', //Server script to process data
                type : 'POST',
                data : formData,
                cache : false,
                contentType : 'multipart/form-data',
                dataType : 'application/json',
                processData : false,
                success : function(data, textStatus, jqXHR) {
                    var userObj = JSON.parse(jqXHR.responseText);
                    alert(userObj);
                },
                error : function(jqXHR, textStatus, errorThrown) {
                    alert(textStatus);

                }
            });

但是它抛出了空指针异常

   Jan 31, 2015 12:51:46 PM org.apache.catalina.core.StandardWrapperValve invoke
SCHWERWIEGEND: Servlet.service() for servlet [Smart_Office] in context with path [/Smart_Office] threw exception
java.lang.NullPointerException
    at com.sun.jersey.multipart.impl.MultiPartReaderClientSide.unquoteMediaTypeParameters(MultiPartReaderClientSide.java:244)
    at com.sun.jersey.multipart.impl.MultiPartReaderClientSide.readMultiPart(MultiPartReaderClientSide.java:171)
    at com.sun.jersey.multipart.impl.MultiPartReaderServerSide.readMultiPart(MultiPartReaderServerSide.java:80)
    at com.sun.jersey.multipart.impl.MultiPartReaderClientSide.readFrom(MultiPartReaderClientSide.java:157)
    at com.sun.jersey.multipart.impl.MultiPartReaderClientSide.readFrom(MultiPartReaderClientSide.java:85)
    at com.sun.jersey.spi.container.ContainerRequest.getEntity(ContainerRequest.java:490)
    at com.sun.jersey.spi.container.ContainerRequest.getEntity(ContainerRequest.java:555)
    at com.sun.jersey.multipart.impl.FormDataMultiPartDispatchProvider$FormDataInjectableValuesProvider.getInjectableValues(FormDataMultiPartDispatchProvider.java:122)
    at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$EntityParamInInvoker.getParams(AbstractResourceMethodDispatchProvider.java:153)
    at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:203)
    at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
    at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:302)
    at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
    at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
    at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
    at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1542)
    at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1473)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1419)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1409)
    at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:409)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:540)
    at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:715)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Answer 1

你的服务器端源代码接缝是明智的，因为你已经遵循了一篇写得很好的教程，但是当你试图混合来自这篇文章和那篇文章的代码来带来一个 Ajaxified Upload with Jersey 示例时，这不会无缝地工作。

我要注意的主要问题是服务器端端点和客户端代码之间的内容协商。

我不会进入 Jersey 内部并寻找如何抛出 NPE 但我会建议更新您的客户端 Ajax 调用以省略 contentType 处理，将以下属性设置为 false :

• 内容类型
• 处理数据

并省略 dataType 属性，因此生成的代码如下所示:

var file = $('input[name="file"').get(0).files[0];
var formData = new FormData();
formData.append('file', file);
$.ajax({
  url : '/OIS/rest/upload',
  type : 'POST',
  data : formData,
  cache : false,
  contentType : false,
  processData : false,
  success : function(data, textStatus, jqXHR) {
    var userObj = JSON.parse(jqXHR.responseText);
    alert(userObj);
  },
  error : function(jqXHR, textStatus, errorThrown) {
    alert(textStatus);
  }
});