jaxb的优点和用法

转载

TheOneGIS 2022-11-15 20:40:56 博主文章分类：Java

文章标签 jaxb xml java sed 文章分类 运维

一、jaxb是什么

JAXB是Java Architecture for XML Binding的缩写。可以将一个Java对象转变成为XML格式，反之亦然。

我们把对象与关系数据库之间的映射称为ORM，其实也可以把对象与XML之间的映射称为OXM(Object XML Mapping)。原来JAXB是Java EE的一部分，在JDK1.6中，SUN将其放到了Java SE中，这也是SUN的一贯做法。JDK1.6中自带的这个JAXB版本是2.0，比起1.0(JSR 31)来，JAXB2(JSR 222)用JDK5的新特性Annotation来标识要作绑定的类和属性等，这就极大简化了开发的工作量。

二、jaxb应用模式

在JAVA EE 5\6中，jaxb可以很方便的与jax-rs、jax-ws集成，极大的简化了web service接口的开发工作量。

三、jaxb代码举例

第一步：需要引入

javax.xml.bind.jar

第二步：编写java bean;

[java] view plain copy

package
import
import
import
@XmlRootElement
public class
String name;
int
int
public
return
}
@XmlElement
public void
this.name = name;
}
public int
return
}
@XmlElement
public void setAge(int
this.age = age;
}
public int
return
}
@XmlAttribute
public void setId(int
this.id = id;
}
}

第三步：main方法把java bean转化为xml字符串

[java] view plain copy

package
import
import
import
import
public class
public static void
new
100);
"mkyong");
29);
try
new File("C:\\file.xml");
class);
Marshaller jaxbMarshaller = jaxbContext.createMarshaller();
// output pretty printed
true);
jaxbMarshaller.marshal(customer, file);
jaxbMarshaller.marshal(customer, System.out);
catch
e.printStackTrace();
}
}
}

下面是输出：

[html] view plain copy

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<customer id="100">
<age>29</age>
<name>mkyong</name>
</customer>

四、jaxb开发常用

jdk提供了xjc工具可以使xsd自动生成相应的java bean，这大大提高了开发的效率。同时，我们也可以使用

trang.jar把xml轻松转化为xsd。下面是使用的举例。

第一步：把数据库表映射为xml

[html] view plain copy

<?xml version="1.0" encoding="UTF-8"?>
<User u_id="1" u_name="moto" u_email="aaa@XXX.com"
u_mood="今天放假了" u_state="online" u_mobile="12345678901"
u_hometown="山西" u_job="IT软件工程师" u_avatar="w34353453543r53" />

第二步：使用

trang.jar转化为xsd文件。在命令行执行：

[html] view plain copy

java -jar D:\lib\trang.jar user.xml user.xsd

下面，是生成的User.java。

[java] view plain copy

//
// This file was generated by the JavaTM Architecture for XML Binding(JAXB) Reference Implementation, vJAXB 2.1.10 in JDK 6
// See <a href="http://java.sun.com/xml/jaxb">http://java.sun.com/xml/jaxb</a>
// Any modifications to this file will be lost upon recompilation of the source schema.
// Generated on: 2011.11.13 at 01:26:07 �� CST
//
package
import
import
import
import
import
import
import
import
import
/**
* <p>Java class for anonymous complex type.
*
* <p>The following schema fragment specifies the expected content contained within this class.
*
* <pre>
* <complexType>
* <complexContent>
* <restriction base="{http://www.w3.org/2001/XMLSchema}anyType">
* <attribute name="u_avatar" use="required" type="{http://www.w3.org/2001/XMLSchema}NCName" />
* <attribute name="u_email" use="required" type="{http://www.w3.org/2001/XMLSchema}anySimpleType" />
* <attribute name="u_hometown" use="required" type="{http://www.w3.org/2001/XMLSchema}NCName" />
* <attribute name="u_id" use="required" type="{http://www.w3.org/2001/XMLSchema}integer" />
* <attribute name="u_job" use="required" type="{http://www.w3.org/2001/XMLSchema}NCName" />
* <attribute name="u_mobile" use="required" type="{http://www.w3.org/2001/XMLSchema}integer" />
* <attribute name="u_mood" use="required" type="{http://www.w3.org/2001/XMLSchema}NCName" />
* <attribute name="u_name" use="required" type="{http://www.w3.org/2001/XMLSchema}NCName" />
* <attribute name="u_state" use="required" type="{http://www.w3.org/2001/XMLSchema}NCName" />
* </restriction>
* </complexContent>
* </complexType>
* </pre>
*
*
*/
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "")
@XmlRootElement(name = "User")
public class
@XmlAttribute(name = "u_avatar", required = true)
@XmlJavaTypeAdapter(CollapsedStringAdapter.class)
@XmlSchemaType(name = "NCName")
protected
@XmlAttribute(name = "u_email", required = true)
@XmlSchemaType(name = "anySimpleType")
protected
@XmlAttribute(name = "u_hometown", required = true)
@XmlJavaTypeAdapter(CollapsedStringAdapter.class)
@XmlSchemaType(name = "NCName")
protected
@XmlAttribute(name = "u_id", required = true)
protected
@XmlAttribute(name = "u_job", required = true)
@XmlJavaTypeAdapter(CollapsedStringAdapter.class)
@XmlSchemaType(name = "NCName")
protected
@XmlAttribute(name = "u_mobile", required = true)
protected
@XmlAttribute(name = "u_mood", required = true)
@XmlJavaTypeAdapter(CollapsedStringAdapter.class)
@XmlSchemaType(name = "NCName")
protected
@XmlAttribute(name = "u_name", required = true)
@XmlJavaTypeAdapter(CollapsedStringAdapter.class)
@XmlSchemaType(name = "NCName")
protected
@XmlAttribute(name = "u_state", required = true)
@XmlJavaTypeAdapter(CollapsedStringAdapter.class)
@XmlSchemaType(name = "NCName")
protected
/**
* Gets the value of the uAvatar property.
*
* @return
* possible object is
* {@link String }
*
*/
public
return
}
/**
* Sets the value of the uAvatar property.
*
* @param value
* allowed object is
* {@link String }
*
*/
public void
this.uAvatar = value;
}
/**
* Gets the value of the uEmail property.
*
* @return
* possible object is
* {@link String }
*
*/
public
return
}
/**
* Sets the value of the uEmail property.
*
* @param value
* allowed object is
* {@link String }
*
*/
public void
this.uEmail = value;
}
/**
* Gets the value of the uHometown property.
*
* @return
* possible object is
* {@link String }
*
*/
public
return
}
/**
* Sets the value of the uHometown property.
*
* @param value
* allowed object is
* {@link String }
*
*/
public void
this.uHometown = value;
}
/**
* Gets the value of the uId property.
*
* @return
* possible object is
* {@link BigInteger }
*
*/
public
return
}
/**
* Sets the value of the uId property.
*
* @param value
* allowed object is
* {@link BigInteger }
*
*/
public void
this.uId = value;
}
/**
* Gets the value of the uJob property.
*
* @return
* possible object is
* {@link String }
*
*/
public
return
}
/**
* Sets the value of the uJob property.
*
* @param value
* allowed object is
* {@link String }
*
*/
public void
this.uJob = value;
}
/**
* Gets the value of the uMobile property.
*
* @return
* possible object is
* {@link BigInteger }
*
*/
public
return
}
/**
* Sets the value of the uMobile property.
*
* @param value
* allowed object is
* {@link BigInteger }
*
*/
public void
this.uMobile = value;
}
/**
* Gets the value of the uMood property.
*
* @return
* possible object is
* {@link String }
*
*/
public
return
}
/**
* Sets the value of the uMood property.
*
* @param value
* allowed object is
* {@link String }
*
*/
public void
this.uMood = value;
}
/**
* Gets the value of the uName property.
*
* @return
* possible object is
* {@link String }
*
*/
public
return
}
/**
* Sets the value of the uName property.
*
* @param value
* allowed object is
* {@link String }
*
*/
public void
this.uName = value;
}
/**
* Gets the value of the uState property.
*
* @return
* possible object is
* {@link String }
*
*/
public
return
}
/**
* Sets the value of the uState property.
*
* @param value
* allowed object is
* {@link String }
*
*/
public void
this.uState = value;
}
}