jaxb2-maven-plugin:2.2:xjc -未声明的前缀问题- java 1.7

<?xml version="1.0" encoding="UTF-8"?>
<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xmlns:ns="http://example.com/namespace">
    <ns:element>Value</ns:element>
</root>

<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>com.example</groupId>
    <artifactId>example-project</artifactId>
    <version>1.0-SNAPSHOT</version>

    <build>
        <plugins>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>jaxb2-maven-plugin</artifactId>
                <version>2.2</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>xjc</goal>
                        </goals>
                        <configuration>
                            <packageName>com.example.schema</packageName>
                            <schemaDirectory>${project.basedir}/src/main/resources/xsd</schemaDirectory>
                            <outputDirectory>${project.basedir}/src/main/java</outputDirectory>
                            <clearOutputDir>false</clearOutputDir>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

xjc -d src/main/java -p com.example.schema schema.xsd

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
           xmlns:ns="http://example.com/namespace"
           targetNamespace="http://example.com/namespace"
           elementFormDefault="qualified">

    <xs:element name="element" type="xs:string"/>
</xs:schema>