【撸码师的备忘录】 Java bean 与 xml 互相转化-JDK Marshaller

package lab.s2jh.core.util;

import java.io.StringReader;
import java.io.StringWriter;
import java.util.List;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlElementWrapper;
import javax.xml.bind.annotation.XmlRootElement;

import lab.s2jh.core.annotation.MetaData;
import lab.s2jh.core.exception.ServiceException;
import lombok.Setter;
import lombok.experimental.Accessors;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.collect.Lists;

/**
* Project :       Monster-frameWork
* Author:         XIE-HONGFEI
* Company:        hongfei tld.
* Created Date:   2016/4/1 0001
* Copyright @ 2016 Company hongfei tld. – Confidential and Proprietary
* <p/>
* History:
* ------------------------------------------------------------------------------
*      Date       |      Author     |   Change Description
* 2016/4/1 0001   |      谢xx        |   初版做成
*
*  描述 :
*  1.利用Java内置JAXB对JavaBean进行序列化为xml或将xml反序列化为java bean对象
*  2.涉及实体Bean需有 @XmlRootElement 及 @XmlElement 注解
*    note :
*    @XmlElement注解只能应用在set方法中,如转换对象为ORM-Entity实体对象，则建议不再使用lombok进行代码处理;
*/

public class JaxbUtils {

private static final Logger logger = LoggerFactory.getLogger(JaxbUtils.class);

private JAXBContext jaxbContext;

/**
* 构造所有需要序列化类型的JAXBContent对象
* @param classes
*/
public JaxbUtils(Class<?>... classes) {
try {
jaxbContext = JAXBContext.newInstance(classes);
} catch (JAXBException e) {
e.printStackTrace();
throw new ServiceException("Build JAXBContext Error" + e.getMessage(), e.getCause());
}
}

public String bean2Xml(Object obj) {
try {
//输出到控制台
//createMarshaller().marshal(obj,System.out);

//输出到字符流
StringWriter writer = new StringWriter();

createMarshaller().marshal(obj, writer);

return writer.toString();

} catch (JAXBException e) {
e.printStackTrace();
throw new ServiceException("Operate marshal error" + e.getMessage(), e.getCause());
}
}

public <T> T xml2Bean(String xmlContent) {

StringReader reader = new StringReader(xmlContent);

try {
return (T) createUnmarshaller().unmarshal(reader);
} catch (JAXBException e) {
throw new ServiceException("Resole xml content to bean Error" + e.getMessage(), e.getCause());
}
}

/**
* Create a <tt>Marshaller</tt> object that can be used to convert a
* java content tree into XML data.
*
* @return a <tt>Marshaller</tt> object
*
* @throws JAXBException if an error was encountered while creating the
*                       <tt>Marshaller</tt> object
*/
public Marshaller createMarshaller() {
return createMarshaller(null);
}

/**
* Create a <tt>Marshaller</tt> object that can be used to convert a
* java content tree into XML data.
*
* @return a <tt>Marshaller</tt> object
*
* @throws JAXBException if an error was encountered while creating the
*                       <tt>Marshaller</tt> object
*/
public Marshaller createMarshaller(String encoding) {
try {
Marshaller marshaller = jaxbContext.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
if (StringUtils.isNotBlank(encoding)) {
marshaller.setProperty(Marshaller.JAXB_ENCODING, encoding);
}
return marshaller;
} catch (JAXBException e) {
throw new ServiceException("Create Marshaller Error , " + e.getMessage(), e.getCause());
}

}

/**
* Create an <tt>Unmarshaller</tt> object that can be used to convert XML
* data into a java content tree.
*
* @return an <tt>Unmarshaller</tt> object
*
* @throws JAXBException if an error was encountered while creating the
*                       <tt>Unmarshaller</tt> object
*/
public Unmarshaller createUnmarshaller() {
try {
return jaxbContext.createUnmarshaller();
} catch (JAXBException e) {
throw new ServiceException("Create Unmarshaller Error," + e.getMessage(), e.getCause());
}
}

/**
* @author Administrator
*
*/
@Setter
@Accessors(chain = true)
@XmlRootElement(name = "example")
static class Example {

private String examId;

//针对实体属性与xml节点名称不一致的情况,可采用name指定的方式进行映射;

private String examName;

private List<ExampleChild> childs;

@Override
public String toString() {
return "no:" + examId + "\n" + "name:" + examName;
}

@XmlElement
public String getExamId() {
return examId;
}

@XmlElement(name = "example_name")
public String getExamName() {
return examName;
}

//节点外层包裹 example_childs层
@XmlElementWrapper(name = "example_childs")
@XmlElement(name = "example_child")
public List<ExampleChild> getChilds() {
return childs;
}

}

/**
*
* XmlElement作用于getter
* @author Administrator
*
*/
@Setter
static class ExampleChild {

@MetaData(value = "子节点编号")
private String childNo;

@MetaData(value = "子节点名称")
private String childName;

@XmlElement
public String getChildNo() {
return childNo;
}

@XmlElement
public String getChildName() {
return childName;
}

}

public static void main(String[] args) {

JaxbUtils jaxbUtils = new JaxbUtils(Example.class);

Example example = new Example();

example.setExamId("10086");
example.setExamName("中国移动示例");

List<ExampleChild> childs = Lists.newArrayList();
example.setChilds(childs);
for (int i = 0; i < 3; i++) {
ExampleChild child = new ExampleChild();
child.setChildNo((i + 1) + "");
child.setChildName("子节点名称-" + i);
childs.add(child);
}

System.out.println("=========================  bean2Xml 结果开始  =============================");
System.out.println(jaxbUtils.bean2Xml(example));
System.out.println("=========================  bean2Xml 结果结束  =============================");

String xmlContent = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>\n" + "<example>\n" + "    <examId>10010</examId>\n"
+ "    <example_name>中国联通示例</example_name>\n" + "</example>";

Example example2 = jaxbUtils.xml2Bean(xmlContent);

System.out.println("=========================  xml2Bean 结果开始  =============================");
System.out.println(JsonUtils.writeValueAsString(example2));
System.out.println("=========================  xml2Bean 结果开始  =============================");
}

}

=========================  bean2Xml 结果开始  =============================
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<example>
<example_childs>
<example_child>
<childName>子节点名称-0</childName>
<childNo>1</childNo>
</example_child>
<example_child>
<childName>子节点名称-1</childName>
<childNo>2</childNo>
</example_child>
<example_child>
<childName>子节点名称-2</childName>
<childNo>3</childNo>
</example_child>
</example_childs>
<examId>10086</examId>
<example_name>中国移动示例</example_name>
</example>

=========================  bean2Xml 结果结束  =============================

=========================  xml2Bean 结果开始  =============================
{"examId":"10010","examName":"中国联通示例","childs":null}
=========================  xml2Bean 结果开始  =============================