我有一些使用JAXB API类的代码,这些类已作为Java 6/7/8中的JDK的一部分提供。当我用Java 9运行相同的代码时,在运行时得到错误,指示找不到JAXB类。

从Java 6开始,JAXB类就作为JDK的一部分提供了,那么为什么Java 9再也找不到这些类了呢?


当前回答

在最近的JDK 9.0.1中,这些解决方案都不适合我。

我发现这个依赖列表对于一个正确的功能来说已经足够了,所以你不需要显式地指定——add-module(尽管它是在这些依赖的pom's中指定的)。你只需要指定以下依赖项列表:

<dependencies>
    <dependency>
        <groupId>javax.xml.bind</groupId>
        <artifactId>jaxb-api</artifactId>
        <version>2.3.0</version>
    </dependency>
    <dependency>
        <groupId>com.sun.xml.bind</groupId>
        <artifactId>jaxb-impl</artifactId>
        <version>2.3.0</version>
    </dependency>
    <dependency>
        <groupId>org.glassfish.jaxb</groupId>
        <artifactId>jaxb-runtime</artifactId>
        <version>2.3.0</version>
    </dependency>
    <dependency>
        <groupId>javax.activation</groupId>
        <artifactId>activation</artifactId>
        <version>1.1.1</version>
    </dependency>
</dependencies>

其他回答

这对我很管用。只添加jaxb-api是不够的。

        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>${jaxb-api.version}</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-impl</artifactId>
            <version>${jaxb-api.version}</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-core</artifactId>
            <version>${jaxb-api.version}</version>
        </dependency>

如果你使用的是上面提到的JDK 8,请遵循以下步骤:

添加javax.xml.bind依赖项

<dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.0</version>
</dependency>

清洁maven 安装maven

不是答案,而是一个附录:我得到的原因是,如果JAVA_HOME指向Java 9安装(准确地说是Java版本“9.0.1”),则运行groovysh (Groovy 2.4.13)会失败:

java.lang.reflect.InvocationTargetException
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:564)
        at org.codehaus.groovy.tools.GroovyStarter.rootLoader(GroovyStarter.java:107)
        at org.codehaus.groovy.tools.GroovyStarter.main(GroovyStarter.java:129)
Caused by: java.lang.NoClassDefFoundError: Unable to load class groovy.xml.jaxb.JaxbGroovyMethods due to missing dependency javax/xml/bind/JAXBContext
        at org.codehaus.groovy.vmplugin.v5.Java5.configureClassNode(Java5.java:400)
        at org.codehaus.groovy.ast.ClassNode.lazyClassInit(ClassNode.java:277)
        at org.codehaus.groovy.ast.ClassNode.getMethods(ClassNode.java:397)
        ...
        ..
        .
        ..
        ...
        at org.codehaus.groovy.tools.shell.Groovysh.<init>(Groovysh.groovy:135)
        at org.codehaus.groovy.vmplugin.v7.IndyInterface.selectMethod(IndyInterface.java:232)
        at org.codehaus.groovy.tools.shell.Main.<init>(Main.groovy:66)
        at org.codehaus.groovy.vmplugin.v7.IndyInterface.selectMethod(IndyInterface.java:232)
        at org.codehaus.groovy.tools.shell.Main.main(Main.groovy:163)
... 6 more

解决方案是:

Go to the JAXB Project at github.io ("JAXB is licensed under a dual license - CDDL 1.1 and GPL 2.0 with Class-path Exception") Download jaxb-ri-2.3.0.zip Unzip wherever you put your java infrastructure files (in my case, /usr/local/java/jaxb-ri/). Other solution may exist (maybe via SDKMAN, I dunno) Make sure the jars in the lib subdirectory are on the CLASSPATH. I do it via a script started on bash startup, called /etc/profile.d/java.sh, where I added (among many other lines) the following loop:

打包到函数中…

function extend_qzminynshg {
   local BASE="/usr/local/java"
   for LIB in jaxb-api.jar  jaxb-core.jar  jaxb-impl.jar  jaxb-jxc.jar  jaxb-xjc.jar; do
      local FQLIB="$BASE/jaxb-ri/lib/$LIB"
      if [[ -f $FQLIB ]]; then
         export CLASSPATH=$FQLIB:$CLASSPATH
      fi
    done
}

extend_qzminynshg; unset extend_qzminynshg

它确实有效!

我在App中遇到了同样的问题,在模块级别构建。gradle添加了视图绑定和数据绑定。

早些时候

viewBinding {
    enabled = true
}

dataBinding {
    enabled = true
}

解决

dataBinding {
    enabled = true
}

在项目级构建中。Gradle使用如下

classpath 'com.android.tools.build:gradle:3.6.3'
classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.5.20"

在我的例子中(spring boot fat jar),我只是将以下内容添加到pom.xml。

<dependency>
    <groupId>javax.xml.bind</groupId>
    <artifactId>jaxb-api</artifactId>
    <version>2.3.1</version>
</dependency>