Docx4j 加载 docx 给出 NullPointerException

Question

我想将 docx 转换为 html。我开始编写与 github 中给出的示例相同的代码。这只是加载部分。这本身就是我遇到的问题。

import org.docx4j.Docx4J;
import org.docx4j.openpackaging.exceptions.Docx4JException;
import org.docx4j.openpackaging.packages.WordprocessingMLPackage;

public class Main {

    public static void main(String[] args) throws Docx4JException, 
        String inputfilepath = "myfilepathhere";


        OutputStream os = new FileOutputStream(inputfilepath + ".html");

        WordprocessingMLPackage wordMLPackage = Docx4J
                .load(new FileInputStream(inputfilepath));

    }
}

我收到 NullPointerException。在 github 中看到异常跟踪并在源代码中导航，我怀疑它与此类 https://github.com/plutext/docx4j/blob/master/src/main/java/org/docx4j/jaxb/Context.java 中的 JAXB 相关内容有关

Docx4j 源代码可在https://github.com/plutext/docx4j 获得。

异常跟踪：

Exception in thread "main" org.docx4j.openpackaging.exceptions.Docx4JException: Couldn't get [Content_Types].xml from ZipFile
    at org.docx4j.openpackaging.io3.Load3.get(Load3.java:134)
    at org.docx4j.openpackaging.packages.OpcPackage.load(OpcPackage.java:454)
    at org.docx4j.openpackaging.packages.OpcPackage.load(OpcPackage.java:371)
    at org.docx4j.openpackaging.packages.OpcPackage.load(OpcPackage.java:337)
    at org.docx4j.openpackaging.packages.OpcPackage.load(OpcPackage.java:302)
    at org.docx4j.openpackaging.packages.WordprocessingMLPackage.load(WordprocessingMLPackage.java:170)
    at org.docx4j.Docx4J.load(Docx4J.java:195)
    at Main.main(Main.java:29)
Caused by: org.docx4j.openpackaging.exceptions.InvalidFormatException: Bad [Content_Types].xml
    at org.docx4j.openpackaging.contenttype.ContentTypeManager.parseContentTypesFile(ContentTypeManager.java:713)
    at org.docx4j.openpackaging.io3.Load3.get(Load3.java:132)
    ... 7 more
Caused by: java.lang.NullPointerException
    at org.docx4j.openpackaging.contenttype.ContentTypeManager.parseContentTypesFile(ContentTypeManager.java:679)
    ... 8 more

docx 文档很好（由 Word 2010 创建）。我什至已经解压缩它以查看 Content_Types.xml 是否存在。它就在那里。

我正在使用 Eclipse 和 Java SE 7。我已将所有必需的 jar 文件添加到项目属性中的 Java 构建路径中。

请帮帮我。

更新：

实际上，当我将 Context.java 中的这一行添加到我的类中时，看看这是否是问题所在。

     JAXBContext.newInstance("org.docx4j.openpackaging.contenttype");

我可以在控制台中看到以下异常：

    Exception in thread "main" javax.xml.bind.JAXBException: Provider org.eclipse.persistence.jaxb.JAXBContextFactory not found
 - with linked exception:
[java.lang.ClassNotFoundException: org.eclipse.persistence.jaxb.JAXBContextFactory]
    at javax.xml.bind.ContextFinder.newInstance(Unknown Source)
    at javax.xml.bind.ContextFinder.find(Unknown Source)
    at javax.xml.bind.JAXBContext.newInstance(Unknown Source)
    at javax.xml.bind.JAXBContext.newInstance(Unknown Source)
    at javax.xml.bind.JAXBContext.newInstance(Unknown Source)
    at Main.main(Main.java:26)
Caused by: java.lang.ClassNotFoundException: org.eclipse.persistence.jaxb.JAXBContextFactory
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at javax.xml.bind.ContextFinder.safeLoadClass(Unknown Source)
    ... 6 more

Answer 1

docx4j 支持几种不同的 JAXB 实现：

• 参考实现
• Java 6/7/8 中包含的一个 Sun/Oracle
• EclipseLink MOXy

如果你想使用 MOXy，你需要：

1. 相关的 EclipseLink jars
2. docx4j-MOXy-JAXBContext-3.0.0.jar（仅包含 jaxb.properties 文件）

jaxb.properties 文件只是说：

javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory

如果你使用的是 maven，你只需要添加：

<dependency>
<groupId>org.docx4j</groupId>
<artifactId>docx4j-MOXy-JAXBContext</artifactId>
<version>3.0.0</version>
</dependency>
<dependency>
<groupId>org.eclipse.persistence</groupId>
<artifactId>org.eclipse.persistence.moxy</artifactId>
<version>2.5.1</version>
</dependency>

你的类路径中有 docx4j-MOXy-JAXBContext jar 吗？要么删除它，要么添加相关的 EclipseLink jars

Answer 2

这对我有用，试试这个

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.OutputStream;

import org.docx4j.Docx4J;
import org.docx4j.Docx4jProperties;
import org.docx4j.convert.out.HTMLSettings;
import org.docx4j.openpackaging.exceptions.Docx4JException;
import org.docx4j.openpackaging.packages.WordprocessingMLPackage;

public class Test {
    public static void main(String[] args) throws Docx4JException,
            FileNotFoundException {
        String inputfilepath = "c:/file.docx";


        WordprocessingMLPackage wordMLPackage = Docx4J
                .load(new FileInputStream(inputfilepath));

        // HTML exporter setup (required)
        //.. the HTMLSettings object
        HTMLSettings htmlSettings = Docx4J.createHTMLSettings();

        htmlSettings.setImageDirPath(inputfilepath + "_files");
        htmlSettings.setImageTargetUri(inputfilepath.substring(inputfilepath
                .lastIndexOf("/") + 1) + "_files");
        htmlSettings.setWmlPackage(wordMLPackage);

        OutputStream os = new FileOutputStream(inputfilepath + ".html");

        // If you want XHTML output
        Docx4jProperties.setProperty("docx4j.Convert.Out.HTML.OutputMethodXML", true);

        //Prefer the exporter, that uses a xsl transformation
        Docx4J.toHTML(htmlSettings, os, Docx4J.FLAG_EXPORT_PREFER_XSL);

    }

}