package org.w3c.dom 可以从多个模块访问：<unnamed> , java.xml</unnamed>

Question

I am unable to import org.w3c.dom.NodeList package to Eclipse. It is showing

The package org.w3c.dom is accessible from more than one module: <unnamed> , java.xml" error message in eclipse.

Please let me know how to fix this?

Eclipse Version:

Eclipse IDE for Enterprise Java Developers.

Version: 2019-06 (4.12.0)

Build id: 20190614-1200

Java version:

java version "12.0.1" 2019-04-16

Java(TM) SE Runtime Environment (build 12.0.1+12)

Java HotSpot(TM) 64-Bit Server VM (build 12.0.1+12, mixed mode, sharing)

Answer 1

I had a similar issue because of a transitive xml-apis dependency. I resolved it using a Maven exclusion:

<dependency>
    <groupId>org.apache.xmlgraphics</groupId>
    <artifactId>fop</artifactId>
    <version>0.95</version>
    
    <exclusions>
        <exclusion>
            <groupId>xml-apis</groupId>
            <artifactId>xml-apis</artifactId>
        </exclusion>
    </exclusions>
</dependency>

Another dependency that just causes trouble and I don't have a solution other than removing it is this one:

<dependency>
    <groupId>com.oracle.database.xml</groupId>
    <artifactId>xmlparserv2</artifactId>
    <version>${oracle.version}</version>
</dependency>

Use mvn dependency:tree to see who brings in the transitive dependency, and then exclude that from there.

Answer 2

Disappointingly I don't see any compiler flags to show what jar the problem is with Even -Xlint:module doesn't seem to show up anything useful and eclipse doesn't shed any light on the issue

Instead to find where org.w3c.dom comes from I've been using this script:

mvn dependency:copy-dependencies -DincludeScope=test -DoutputDirectory=deps
for i in deps/*.jar; do if unzip -l $i| grep -q org.w3c.dom; then echo $i; fi ; done

Strictly you don't have to specify the scope test as that's the default but I've included it as you might want to use compile instead

Answer 3

On my side, I've spent a few hours to understand my issue, really closed to this one.
The package org.w3c.dom is accessible from more than one module: <unnamed>, java.xml

I wanted to migrate a project from Java 8 to Java 11. A few library issues. Easy to fix. But on this one,

• I've tried to create module-info.java → it was worst.

• Find a issue on my OS (debian 10) → even if Java 11 was default JRE, $JAVA_HOME was not rightly set for maven build. And when I was thinking it was only an Eclipse issue, I finally consider that it was a global compilation problem. To fix this I had to add following line in ~/.mavenrc

  JAVA_HOME=/usr/lib/jvm/default-java

• Deep analysis on maven dependencies shows me a third-level dependency on xom .jar which trigger the issue. Dependency was linked to Saxon HE library → an upgrade to VERSION 9.9.X has resolved this boring problem.

Hope this will helps other people.

Answer 4

In my case, it was caused by combining the usage of:

• JDK 11
• dom4j 2.1.3 library

As pointed out by others, the root cause is that dom4j and its dependencies (eg, pull-parser ) use some packages names ( javax.xml.parsers , org.w3c.dom ) that have been used by the JDK.

I had to remove dom4j to solve the problem. Just use JDK's own XML api.

Answer 5

For Java 9 and higher Delete org.w3c.dom jar file from the class path, and you are done. By the way delete module info file too. You don't need to add the external jar file, its already included in the system library of java 9 and higher.

Answer 6

Just open the configure build path and verify the modules which are all you have added as part of the project, which contains the class files as *

org.w3c.dom

This error, we usually gets in Java due to same kind of multiple API packages added in one project.

As, am using the same version as you mentioned, am not facing any issues., so just make sure that you don't have any duplicate modules.

Answer 7

In my case I was using:
JDK 14 and xmlbeans.jar library.
I just had to remove the xmlbeans.jar library and it surely solved the issue.

Answer 8

org.w3c.dom is used in:

<dependency>
    <groupId>org.apache.xmlbeans</groupId>
    <artifactId>xmlbeans</artifactId>
    <version>2.4.0</version>
</dependency>

Check if this is imported transitively via some other dependency. Exclude the same

Add dependency for:

<dependency>
    <groupId>org.apache.xmlbeans</groupId>
    <artifactId>xmlbeans</artifactId>
    <version>2.6.0</version>
</dependency>

Answer 9

I am unable to import org.w3c.dom.NodeList package to Eclipse. It is showing

The package org.w3c.dom is accessible from more than one module: <unnamed> , java.xml" error message in eclipse.

Please let me know how to fix this ?

Eclipse Version:

Eclipse IDE for Enterprise Java Developers.

Version: 2019-06 (4.12.0)

Build id: 20190614-1200

Java version:

java version "12.0.1" 2019-04-16

Java(TM) SE Runtime Environment (build 12.0.1+12)

Java HotSpot(TM) 64-Bit Server VM (build 12.0.1+12, mixed mode, sharing)

Answer 10

If you are in a simple Java Project , not Maven. Then just remove the dom-jaxb jar from the Libraries.

Steps : Right click on project -> Properties -> Java BuildPath -> Libraries Tab -> select on jars such as dom-2.3.0-jaxb-1.0.6(version might differ) -> Remove.

Now it will build without error.

The error is occurring because "org.w3c.dom.Document" is coming from both the removed "dom-2.3.0-jaxb-1.0.6" jar and from Java's in-built libraries. Removing additional jar will let it come only from Java's in-built libraries.

Answer 11

You need to manually check and remove all the jars (libraries) which has the possibility of conflicting with java.xml package.

In my case, I edited my .classpath file and removed the following jars and it resolved the issue:

jtidy.jar, castor-0.9.5.4-xml.jar, xercesImpl.jar, xml-apis.jar

Answer 12

In my case, culprit was Apache POI library. Added exclusion as below

<!-- Apache POI Library for Parsing Excel Sheets -->
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi-ooxml</artifactId>
        <version>5.0.0</version>
        <exclusions>
            <exclusion>
                <groupId>org.apache.xmlbeans</groupId>
                <artifactId>xmlbeans</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

Answer 13

You can use this code (for example in a unit test) to determine all JARs that contain a class:

getClass().getClassLoader().getResources("org/w3c/dom/NodeList.class");

This gives you an Enumeration . The easiest way to print this is:

Collections.list(e).forEach(System.out::println);

Answer 14

In a Gradle land, you can track down which dependencies are contributing to xml-api s by running:

gradlew -q dependencies

(or core:dependencies for the core project in a multi-project environment).

In my case, xml-apis was being requested by both net.sourceforge.htmlunit and xom , so the solution is to exclude xml-apis in your build.gradle as so:

dependencies {
  implementation("net.sourceforge.htmlunit:neko-htmlunit:$nekoHtmlUnitVersion") {
    exclude group: "xml-apis"
  }
  testImplementation("xom:xom:$xomVersion") {
    exclude group: "xml-apis"
  }
  // ...other dependencies
}

Answer 15

Sometimes even when you have removed duplicate classes the same error "The package org.w3c.dom is accessible from more than one module" may remain, especially with IDEs.

IT IS NOT always enought to find only org.w3c.dom ..,. You may need to remove duplicate classes which share the same parent package org.w3c.xxx, for example org.w3c.css

We managed to fix it like this:

• In IDE search classes starting with: org.w3c
• Add pom.xml exclusions or increase library version, since org.w3c has been removed in some newer lib versions
• Test compile in both IDE and command line

If the issue persists:

• Export all dependencies to file: mvn dependency:copy-dependencies -DincludeScope=test -DoutputDirectory=deps
• From jar-files find any classes of org.w3c
• Keep adjusting pom.xml