#StackBounty: #java #maven #google-app-engine #blobstore #appengine-maven-plugin How to add javax.activation.DataSource to App Engine d…

Bounty: 50

tl;dr: How do I add the javax.activation.DataSource dependency to a server run through the App Engine Maven plugin?

I’m using the App Engine Maven plugin to deploy to a local App Engine server, and I’m trying to use the Blobstore API to upload a file. I’m using Java 11.

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>io.happycoding</groupId>
  <artifactId>blobstore-test</artifactId>
  <version>1</version>
  <packaging>war</packaging>

  <properties>
    <!-- App Engine currently supports Java 8 -->
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <failOnMissingWebXml>false</failOnMissingWebXml>
  </properties>

  <dependencies>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>4.0.1</version>
      <scope>provided</scope>
    </dependency>

    <dependency>
      <groupId>org.apache.taglibs</groupId>
      <artifactId>taglibs-standard-spec</artifactId>
      <version>1.2.5</version>
    </dependency>

    <dependency>
      <groupId>com.google.appengine</groupId>
      <artifactId>appengine-api-1.0-sdk</artifactId>
      <version>1.9.59</version>
    </dependency>

  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>com.google.appengine</groupId>
        <artifactId>appengine-maven-plugin</artifactId>
        <version>1.9.71</version>
      </plugin>
    </plugins>
  </build>
</project>

index.jsp

<%@ page import="com.google.appengine.api.blobstore.BlobstoreServiceFactory" %>

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
  </head>
  <body>

    <form action="<%= BlobstoreServiceFactory.getBlobstoreService().createUploadUrl("/submit") %>" 
      method="POST"
      enctype="multipart/form-data">

      Enter some text:
      <br/>
      <textarea name="text"></textarea>
      <br/>
      Select a file:
      <input type="file" name="image">
      <br/>
      <input type="submit" value="Submit">
    </form>

  </body>
</html>

SubmitServlet.java

package io.happycoding.servlets;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/submit")
public class SubmitServlet extends HttpServlet {

  @Override
  public void doPost(HttpServletRequest request, HttpServletResponse response) {
    System.out.println("data submitted");
  }
}

Command to run the local server: mvn appengine:devserver

I can successfully run a local server, and I can see that the form is rendered correctly, including the Blobstore URL.

However, when I submit the form, I get this error:

java.lang.NoClassDefFoundError: javax/activation/DataSource
    at com.google.appengine.api.blobstore.dev.UploadBlobServlet.handleUpload(UploadBlobServlet.java:171)
    at com.google.appengine.api.blobstore.dev.UploadBlobServlet.access$000(UploadBlobServlet.java:69)
    at com.google.appengine.api.blobstore.dev.UploadBlobServlet$1.run(UploadBlobServlet.java:115)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at com.google.appengine.api.blobstore.dev.UploadBlobServlet.doPost(UploadBlobServlet.java:112)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:867)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1623)
    at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:134)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:63)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:48)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
    at com.google.appengine.tools.development.jetty9.StaticFileFilter.doFilter(StaticFileFilter.java:123)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectRequest(DevAppServerModulesFilter.java:366)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doDirectModuleRequest(DevAppServerModulesFilter.java:349)
    at com.google.appengine.tools.development.DevAppServerModulesFilter.doFilter(DevAppServerModulesFilter.java:116)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
    at com.google.appengine.tools.development.DevAppServerRequestLogFilter.doFilter(DevAppServerRequestLogFilter.java:44)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1602)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:540)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146)
    at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:524)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)
    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1588)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1345)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:480)
    at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1557)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1247)
    at com.google.appengine.tools.development.jetty9.DevAppEngineWebAppContext.doScope(DevAppEngineWebAppContext.java:94)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
    at com.google.appengine.tools.development.jetty9.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:595)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
    at org.eclipse.jetty.server.Server.handle(Server.java:502)
    at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:364)
    at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260)
    at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:305)
    at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)
    at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:118)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168)
    at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:126)
    at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:366)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:765)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:683)
    at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.ClassNotFoundException: javax.activation.DataSource
    at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:471)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:588)
    at com.google.appengine.tools.development.DevAppServerClassLoader.loadClass(DevAppServerClassLoader.java:108)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    ... 57 more

Some Googling reveals quite a few questions about this problem:

The answers to these questions suggest adding a combination of these dependencies:

<dependency>
  <groupId>javax.activation</groupId>
  <artifactId>javax.activation-api</artifactId>
  <version>1.2.0</version>
</dependency>

<dependency>
    <groupId>javax.activation</groupId>
    <artifactId>activation</artifactId>
    <version>1.1.1</version>
</dependency>

<dependency>
    <groupId>com.sun.activation</groupId>
    <artifactId>javax.activation</artifactId>
    <version>1.2.0</version>
</dependency>

I’ve tried adding each of these, and I’ve tried adding all of them. But no matter what, I still get the above error.

I understand why this is happening: Java 8 included the javax.activation.DataSource class, and it was subsequently removed. So since I’m using Java 11, that class is missing. But none of the dependencies I’ve tried so far seem to provide the missing class, possibly because I’m using the App Engine Maven plugin instead of running my own server?

How do I add this dependency to a project that uses the App Engine Maven plugin?


Get this bounty!!!

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.