Java操作XML(10)--JiBX使用

Jibx是一款优秀的实现java对象和XML相互绑定的框架，功能类似JAXB。本文主要介绍Jibx的基本使用，文中所使用到的软件版本：Java 1.8.0_181、jibx 1.4.1。

1、JiBX简介

JiBX使用绑定文挡(binding definition document)来定义XML与Java对象转换的规则，这个文挡就是联系XML与Java对象之间的桥梁；详细说明可参考官网：http://jibx.sourceforge.net。
JiBX的使用过程分成两步：
第一步是Binding Compiler，这是一个前期准备过程，包括定义绑定文挡，定义与XML绑定在一起的Java对象，然后编译生成中间操作类。
第二步是Runtime，使用Binding Compiler编译好的中间操作类处理XML和Java对象的转换；如果需要修改映射需要重新生成中间类。

2、JiBX使用

2.1、引入依赖及JiBX的maven插件

<dependency>
    <groupId>org.jibx</groupId>
    <artifactId>jibx-run</artifactId>
    <version>1.3.3</version>
</dependency>
...

<build>
    ...    
    <plugins>
        <plugin>
            <!-- 生成jibx class信息 -->
            <groupId>org.jibx</groupId>
            <artifactId>jibx-maven-plugin</artifactId>
            <version>1.3.3</version>
            <configuration>
                <schemaBindingDirectory>src/main/java</schemaBindingDirectory>
                <includeSchemaBindings>
                    <includeSchemaBindings>**/*binding.xml</includeSchemaBindings>
                </includeSchemaBindings>
                <verbose>true</verbose>
            </configuration>
            <executions>
                <execution>
                    <id>jibx-bind</id>
                    <phase>compile</phase>
                    <!-- 把jibx绑定到了comile编译阶段 -->
                    <goals>
                        <goal>bind</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>

</build>

2.2、xml样例文件

<?xml version="1.0" encoding="utf-8" ?>
<school:grade xmlns:school="http://www.w3.org/TR/html4/school/">
    <school:student rollno="1" age="11">
        <school:firstname>cxx1</school:firstname>
        <school:lastname>Bob1</school:lastname>
        <school:nickname>stars1</school:nickname>
        <school:marks>85</school:marks>
    </school:student>
    <school:student rollno="2" age="12">
        <school:firstname>cxx2</school:firstname>
        <school:lastname>Bob2</school:lastname>
        <school:nickname>stars2</school:nickname>
        <school:marks>85</school:marks>
    </school:student>
    <school:student rollno="3" age="13">
        <school:firstname>cxx3</school:firstname>
        <school:lastname>Bob3</school:lastname>
        <school:nickname>stars3</school:nickname>
        <school:marks>85</school:marks>
    </school:student>
</school:grade>

2.3、xml对应的类

2.3.1、班级类

package com.abc.demo.general.xml;

import java.util.List;

/**
 * 班级
 */
public class Grade {
    private List<Student> students;

    public List<Student> getStudents() {
        return students;
    }

    public void setStudents(List<Student> students) {
        this.students = students;
    }

    @Override
    public String toString() {
        return "Grade{" +
                "students=" + students +
                '}';
    }
}

2.3.2、学生类

package com.abc.demo.general.xml;

/**
 * 学生
 */
public class Student {
    private int rollno;
    private int age;
    private String firstname;
    private String lastname;
    private String nickname;
    private String marks;

    public Student() {}

    public Student(int rollno, int age, String firstname, String lastname, String nickname, String marks) {
        this.rollno = rollno;
        this.age = age;
        this.firstname = firstname;
        this.lastname = lastname;
        this.nickname = nickname;
        this.marks = marks;
    }

    public int getRollno() {
        return rollno;
    }

    public void setRollno(int rollno) {
        this.rollno = rollno;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getFirstname() {
        return firstname;
    }

    public void setFirstname(String firstname) {
        this.firstname = firstname;
    }

    public String getLastname() {
        return lastname;
    }

    public void setLastname(String lastname) {
        this.lastname = lastname;
    }

    public String getNickname() {
        return nickname;
    }

    public void setNickname(String nickname) {
        this.nickname = nickname;
    }

    public String getMarks() {
        return marks;
    }

    public void setMarks(String marks) {
        this.marks = marks;
    }

    @Override
    public String toString() {
        return "Student{" +
                "rollno=" + rollno +
                ", age=" + age +
                ", firstname='" + firstname + '\'' +
                ", lastname='" + lastname + '\'' +
                ", nickname='" + nickname + '\'' +
                ", marks='" + marks + '\'' +
                '}';
    }
}

2.4、绑定文档

绑定文档可以自己编写(绑定文档的规则介绍详见:http://jibx.sourceforge.net/binding/xml-summary.html)，也可以通过JiBX提供的工具来生成：

java -cp ../../lib/jibx-tools.jar:bin org.jibx.binding.generator.BindGen org.jibx.starter1.Order

这里自己编写binding.xml:

<binding>
    <mapping name="grade" class="com.abc.demo.general.xml.Grade">
        <namespace prefix="school" uri="http://www.w3.org/TR/html4/school/" default="elements"></namespace>
        <collection field="students" type="java.util.ArrayList" item-type="com.abc.demo.general.xml.Student">
        </collection>
    </mapping>
    <mapping name="student" class="com.abc.demo.general.xml.Student">
        <namespace prefix="school" uri="http://www.w3.org/TR/html4/school/" default="elements"></namespace>
        <value style="attribute" name="rollno" field="rollno"></value>
        <value style="attribute" name="age" field="age"></value>
        <value name="firstname" field="firstname"></value>
        <value name="lastname" field="lastname"></value>
        <value name="nickname" field="nickname"></value>
        <value name="marks" field="marks"></value>
    </mapping>
</binding>

2.5、JiBX使用例子

2.5.1、Binding Compiler

使用binding.xml及对应的实体类编译生成中间操作类。

 点击“compile”后会生成相应的绑定类：

 

2.5.1、Runtime

使用Binding Compiler编译好的中间操作类来处理O/X转换：Java对象转成xml以及xml转成Java对象。

package com.abc.demo.general.xml;

import org.jibx.runtime.BindingDirectory;
import org.jibx.runtime.IBindingFactory;
import org.jibx.runtime.IMarshallingContext;
import org.jibx.runtime.IUnmarshallingContext;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.ArrayList;
import java.util.List;

/**
 * 使用JiBX处理xml
 */
public class JiBXCase {
    private static Logger logger = LoggerFactory.getLogger(JiBXCase.class);

    /**
     * java对象转成xml
     * @throws Exception
     */
    @Test
    public void javaToXml() throws Exception {
        List<Student> students = new ArrayList<>();
        Student student1 = new Student(1, 11,"cxx1", "Bob1", "stars1", "85");
        Student student2 = new Student(2, 12, "cxx2", "Bob2", "stars2", "85");
        Student student3 = new Student(3, 13, "cxx3", "Bob3", "stars3", "85");
        students.add(student1);
        students.add(student2);
        students.add(student3);
        Grade grade = new Grade();
        grade.setStudents(students);

        IBindingFactory factory = BindingDirectory.getFactory(Grade.class);
        IMarshallingContext marshallingContext = factory.createMarshallingContext();
        marshallingContext.marshalDocument(grade, "utf-8", true, System.out);
    }

    /**
     * xml转成java对象
     * @throws Exception
     */
    @Test
    public void xmlToJava() throws Exception {
        IBindingFactory factory = BindingDirectory.getFactory(Grade.class);
        IUnmarshallingContext unmarshallingContext = factory.createUnmarshallingContext();
        Grade grade = (Grade) unmarshallingContext.unmarshalDocument(JiBXCase.class.getResourceAsStream("student3.xml"), null);
        logger.info(grade.toString());
    }
}