org.apache.xmlgraphics.image.loader.ImageException：不支持该文件格式。未找到 ImagePreloader

Question

我正在使用 Apache FOP 1.1(Java) 生成 PDF 文件。它在 Windows 机器上工作正常，但当我使用 Ubuntu 机器时，出现此错误

org.apache.xmlgraphics.image.loader.ImageException: The file format is not supported.  No ImagePreloader found

我有点困惑。请给我解决方案来解决这个问题。谢谢

Answer 1

问题是jar 文件和jar 文件META-INF/services/中都存在的配置文件之间存在冲突。fopxmlgraphics-commons

如果您正在使用 Maven 并且想要避免有时可能会造成麻烦的排除，您可以使用Maven Shade 插件构建一个 jar 并强制将 .jar 中的配置文件串联起来META-INF/services/。像这样的片段对我有用：

   <build>
        <finalName>desired_jar_name</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>3.1.0</version>
                <configuration>
                    <transformers>
                        <transformer
                            implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer" />
                        <transformer
                            implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                            <mainClass>my.main.class</mainClass>
                        </transformer>
                    </transformers>
                </configuration>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

Answer 2

我只从 stackoverflow 得到了解决方案。我要特别感谢这篇文章的作者 Apache FOP in a Java Applet - No ImagePreloader found for data

With reference from above post , To give precedence to XmlGraphics
API , 
  1. I have excluded XML-graphics API from FOP jar
  2. added new maven dependency XmlGraphics API and placed above FOP dependancy
  3. so that POM will give priority


   <dependency>
        <groupId>xmlgraphics-commons</groupId>
        <artifactId>xmlgraphics-commons</artifactId>
        <version>1.4</version>
    </dependency>

    <dependency>
        <groupId>org.apache.xmlgraphics</groupId>
        <artifactId>fop</artifactId>
        <version>1.1</version>
        <exclusions>
            <exclusion>
                <artifactId>xmlgraphics-commons</artifactId>
                <groupId>org.apache.xmlgraphics</groupId>
            </exclusion>
        </exclusions>
    </dependency>

    <dependency>
        <groupId>org.apache.avalon.framework</groupId>
        <artifactId>avalon-framework-api</artifactId>
        <version>4.3.1</version>
    </dependency>

    <dependency>
        <groupId>org.apache.avalon.framework</groupId>
        <artifactId>avalon-framework-impl</artifactId>
        <version>4.3.1</version>
    </dependency>

谢谢