在 Java 中使用 Rest API 上传文件答案

【问题标题】：File Upload using Rest API in Java在 Java 中使用 Rest API 上传文件
【发布时间】：2014-07-22 14:51:40
【问题描述】：

我是 REST API 的新手。我想使用 REST API 将用户选择的文件上传到用户提供的路径（远程或本地路径）。我的 html 文件有 1 个文本框和 1 个文件选择器。用户将在文本框中输入 FilePath（本地或远程计算机文件夹位置）。请建议如何解决此问题。

这是我的代码：

文件上传.html：：

<body>
    <form action="rest/file/upload" method="post" enctype="multipart/form-data">
        <p>
            Select a file : <input type="file" name="file" size="45" />
        </p>
        <p>Target Upload Path : <input type="text" name="path" /></p>
        <input type="submit" value="Upload It" />
   </form>
</body>

UploadFileService.java

@Path("/file")
public class UploadFileService {

    @POST
    @Path("/upload")
    @Consumes(MediaType.MULTIPART_FORM_DATA)
    public Response uploadFile(
            @FormDataParam("file") InputStream uploadedInputStream,
            @FormDataParam("file") FormDataContentDisposition fileDetail,
            @FormParam("path") String path) {

        /*String uploadedFileLocation = "d://uploaded/"                                                                 + fileDetail.getFileName();*/

        /*String uploadedFileLocation = //10.217.14.88/Installables/uploaded/"                                                                  + fileDetail.getFileName();*/
        String uploadedFileLocation = path
                + fileDetail.getFileName();

        // save it
        writeToFile(uploadedInputStream, uploadedFileLocation);

        String output = "File uploaded to : " + uploadedFileLocation;

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

    }

    // save uploaded file to new location
    private void writeToFile(InputStream uploadedInputStream,
            String uploadedFileLocation) {

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

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

            e.printStackTrace();
        }

    }

}

Web.xml

<display-name>JAXRSFileUploadJerseyExample</display-name>
<servlet>
    <servlet-name>jersey-serlvet</servlet-name>
    <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
    <init-param>
        <param-name>com.sun.jersey.config.property.packages</param-name>
        <param-value>com.mkyong.rest</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>jersey-serlvet</servlet-name>
    <url-pattern>/rest/*</url-pattern>
</servlet-mapping>

例外：

HTTP Status 500 - com.sun.jersey.api.container.ContainerException: Exception obtaining parameters
type Exception report
message com.sun.jersey.api.container.ContainerException: Exception obtaining parameters
description The server encountered an internal error that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: com.sun.jersey.api.container.ContainerException: Exception obtaining parameters
        com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:425)
        com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
        com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
root cause
com.sun.jersey.api.container.ContainerException: Exception obtaining parameters
        com.sun.jersey.server.impl.inject.InjectableValuesProvider.getInjectableValues(InjectableValuesProvider.java:54)
        com.sun.jersey.multipart.impl.FormDataMultiPartDispatchProvider$FormDataInjectableValuesProvider.getInjectableValues(FormDataMultiPartDispatchProvider.java:125)
        com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$EntityParamInInvoker.getParams(AbstractResourceMethodDispatchProvider.java:153)
        com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:203)
        com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
        com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
        com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
        com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
        com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
        com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
        com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
        com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
        com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
        com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
        com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
        com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
        com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
root cause
java.lang.IllegalStateException: The @FormParam is utilized when the content type of the request entity is not application/x-www-form-urlencoded
        com.sun.jersey.server.impl.model.parameter.FormParamInjectableProvider$FormParamInjectable.getValue(FormParamInjectableProvider.java:81)
        com.sun.jersey.server.impl.inject.InjectableValuesProvider.getInjectableValues(InjectableValuesProvider.java:46)
        com.sun.jersey.multipart.impl.FormDataMultiPartDispatchProvider$FormDataInjectableValuesProvider.getInjectableValues(FormDataMultiPartDispatchProvider.java:125)
        com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$EntityParamInInvoker.getParams(AbstractResourceMethodDispatchProvider.java:153)
        com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:203)
        com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
        com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
        com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
        com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
        com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
        com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
        com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
        com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
        com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
        com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
        com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
        com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
        com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:699)
        javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

【问题讨论】：

标签： java web-services rest file-upload jersey

【解决方案1】：

我已经更新了下面类中的方法签名并且它工作正常。而不是@FormParam，使用@FormDataParam("path")字符串路径，它解决了我的问题。以下是更新后的代码：

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.ws.rs.Consumes;
import javax.ws.rs.FormParam;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;

import com.sun.jersey.core.header.FormDataContentDisposition;
import com.sun.jersey.multipart.FormDataParam;

@Path("/file")
public class UploadFileService {

@POST
@Path("/upload")
@Consumes(MediaType.MULTIPART_FORM_DATA)
public Response uploadFile(
        @FormDataParam("file") InputStream uploadedInputStream,
        @FormDataParam("file") FormDataContentDisposition fileDetail,
        @FormDataParam("path") String path) {


    // Path format //10.217.14.97/Installables/uploaded/
    System.out.println("path::"+path);
    String uploadedFileLocation = path
            + fileDetail.getFileName();

    // save it
    writeToFile(uploadedInputStream, uploadedFileLocation);

    String output = "File uploaded to : " + uploadedFileLocation;

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

}

// save uploaded file to new location
private void writeToFile(InputStream uploadedInputStream,
        String uploadedFileLocation) {

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

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

        e.printStackTrace();
    }

   }

   }

【讨论】：

java 代码会接受任何类型的文件并将其保存在定义的位置吗？我想保存 .pdf、.doc、.jpg 等文件类型
如果上面的代码对 jars 有问题，请使用这个 maven 导入：com.sun.jerseyjersey-server1.8 com.sun.jersey.contribsjersey-multipart1.8

【解决方案2】：

另一种可能的解决方案

@Consumes 注释并将其设置为应用程序八位字节流。使用 PUT http 方法。然后在客户端，从文件中读取字节并上传。

我的 REST 服务压缩文件的示例代码在这里 - https://stackoverflow.com/a/32253028/15789

希望这会有所帮助。

【讨论】：