从java类生成xsd的实用程序

Question

I want to generate xsd for the following class

public class Node{
  private String value;
  private List<Node> childrens;

}

What is the best utility to generate xsd schema for such code

In general I want to implement simple tree. I'm already using jaxb for generating the classes from schema.

Answer 1

You can use the generateSchema API on JAXBContext to generate an XML schema:

import java.io.IOException;
import javax.xml.bind.*;
import javax.xml.transform.Result;
import javax.xml.transform.stream.StreamResult;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(Node.class);   
        jc.generateSchema(new SchemaOutputResolver() {

            @Override
            public Result createOutput(String namespaceURI, String suggestedFileName)
                throws IOException {
                return new StreamResult(suggestedFileName);
            }

        });

    }

}

Answer 2

If you're already using JAXB, you can use the schemagen tool for creating an XSD:

• http://docs.oracle.com/javase/6/docs/technotes/tools/share/schemagen.html
• http://publib.boulder.ibm.com/infocenter/wasinfo/v7r0/index.jsp?topic=%2Fcom.ibm.websphere.express.doc%2Finfo%2Fexp%2Fae%2Ftwbs_jaxbjava2schema.html

There are also Ant tasks and Maven plugins for doing the same in an automated fashion.

Answer 3

If you are using Eclipse IDE, you can follow the steps from this official documentation:

Generating Schema from Classes

1. From the Navigator or Project Explorer, select File > New > Other. The Select a wizard dialog appears.
2. Select JAXB > Schema from JAXB Classes and then click Next. The Generate Schema from Classes page of the Generate Schema from JAXB Classes Wizard appears.
3. Select the project, package, or classes from which to generate the schema and click Finish.

Answer 4

There are also Ant tasks and Maven plugins for doing the same in an automated fashion.

Yes indeed there are. Before you have to figure it out for yourself here is the maven version:

(1) Add the maven plugin to your pom.xml

<build>
        <plugins>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>jaxb2-maven-plugin</artifactId>
                <version>2.4</version>
                <executions>
                    <execution>
                        <id>schemagen</id>
                        <goals>
                            <goal>schemagen</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <!-- Renaming default 'schema1.xsd' -->
                    <transformSchemas>
                      <transformSchema>
                        <uri>http://www.your.url/namespace/foo</uri>
                        <toFile>your-schema-name.xsd</toFile>
                      </transformSchema>
                    </transformSchemas>
                </configuration>
            </plugin>
            ...
        <plugins>       
<build>

(2) Add a package info (optional) class:

package-info.java to your (java) package(s). This file contains the package name:

@javax.xml.bind.annotation.XmlSchema(namespace = "http://www.your.url/namespace/foo", elementFormDefault = javax.xml.bind.annotation.XmlNsForm.QUALIFIED)
package url.your.namespace.foo;

(3) Add XML annotations to your classes like

@XmlRootElement(name = "Container")
@XmlAccessorType(XmlAccessType.FIELD)
public class Container {

  @XmlElement(name = "Info", required = true)
  private Info info;
  @XmlElement(name = "Unit")
  private Unit unit;
...}

Then you just have to execute your maven build and then in the target folder you'll find you xsd file.