java对象数据转xml文件(加<![CDATA[]]>)[注解方式]

java对象数据转xml文件

这种操作一般发生在导出文件,我在这里记录一下这一系列注解的使用,还有我遇到的问题及解决方法;
问题:对象属性中有可能存在计算逻辑'<'或'>',而在xml文件中这两个符号是不合法的,会转换为<和>,这样数据就'坏'了,所以<![CDATA[]]>的加入是非常有必要的!

需要导入类

1.这是在你需要导出的实体类中用到的(一般都是DTO[扩展类])

import java.io.Serializable;

import javax.xml.bind.annotation.XmlAccessType;

import javax.xml.bind.annotation.XmlAccessorType;

import javax.xml.bind.annotation.XmlElement;

import javax.xml.bind.annotation.XmlRootElement;

import javax.xml.bind.annotation.XmlType;

import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;

2.这是解决<,>两个符号自动转化的工具类用到的

import java.io.StringReader;

import java.io.StringWriter;

import javax.xml.bind.JAXBContext;

import javax.xml.bind.Marshaller;

import javax.xml.bind.Unmarshaller;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

注解的使用

1.@XmlRootElement，用于类级别的注解，对应xml的跟元素。通过name属性定义这个根节点的名称。

2.@XmlAccessorType，定义映射这个类中的何种类型都需要映射到xml。(如果不存在@XmlAccessorType,默认使用XmlAccessType.PUBLIC_MEMBER注解)

　　参数：XmlAccessType.FIELD: java对象中的所有成员变量。

　　XmlAccessType.PROPERTY：java对象中所有通过getter/setter方式访问的成员变量。

　　XmlAccessType.PUBLIC_MEMBER：java对象中所有的public访问权限的成员变量和通过getter/setter方式访问的成员变量。

　　XmlAccessType.NONE: java对象的所有属性都不映射为xml的元素。

3.@XmlAttribute，用于把java对象的属性映射为xml的属性,并可通过name属性为生成的xml属性指定别名。

4.@XmlElement，指定一个字段或get/set方法映射到xml的节点。通过name属性定义这个根节点的名称。

5.@XmlElementWrapper，为数组或集合定义一个父节点。通过name属性定义这个父节点的名称。

xml,javaBeen的相互装换

public class JaxbUtil
{

/**
* 日志
*/
private static final Log _logger = LogFactory.getLog (JaxbUtil.class);

public static String convertToXml (Object obj)
{
return convertToXml (obj, "UTF-8");
}

/**
* JavaBean转换成xml
*
* @param obj
* @param encoding
* @return
*/
public static String convertToXml (Object obj, String encoding)
{
String result = null;
try
{
JAXBContext context = JAXBContext.newInstance (obj.getClass ());
Marshaller marshaller = context.createMarshaller ();
marshaller.setProperty (Marshaller.JAXB_FORMATTED_OUTPUT, true);
marshaller.setProperty (Marshaller.JAXB_ENCODING, encoding);
StringWriter writer = new StringWriter ();
marshaller.marshal (obj, writer);
result = writer.toString ();
}
catch (Exception ex)
{
_logger.error (ex.getMessage (), ex);
}
return result;
}

/**
* xml转换成JavaBean
*
* @param xml
* @param c
* @return
*/
@SuppressWarnings ("unchecked")
public static <T> T converyToJavaBean (String xml, Class <T> c)
{
T t = null;
try
{
JAXBContext context = JAXBContext.newInstance (c);
Unmarshaller unmarshaller = context.createUnmarshaller ();
t = (T) unmarshaller.unmarshal (new StringReader (xml));
}
catch (Exception ex)
{
_logger.error (ex.getMessage (), ex);
}
return t;
}

}

解决保护数据问题的工具类

public class CDataAdapter extends XmlAdapter <String, String>
{
@Override
public String marshal (String v) throws Exception
{
return "<![CDATA[" + v + "]]>";
}
@Override
public String unmarshal (String v) throws Exception
{
if ("<![CDATA[]]>".equals (v))
{
return "";
}
String v1 = null;
String v2 = null;
String subStart = "<![CDATA[";
int a = v.indexOf (subStart);
if (a >= 0)
{
v1 = v.substring (subStart.length (), v.length ());
}
else
{
return v;
}
String subEnd = "]]>";
int b = v1.indexOf (subEnd);
if (b >= 0)
{
v2 = v1.substring (0, b);
}
return v2;
}

}

对应实例

定义类

@XmlAccessorType (XmlAccessType.FIELD)
@XmlRootElement
@XmlType (name = "indicatorDefine", propOrder =
{ "indCode", "indDescs", "indTypeCode", "monTableName", "monTableDescs", "monTableFieldName", "monTableFieldDescs",
"validateType", "validateDescs", "validateScript", "validateMethod", "relateTable", "relateScript", "stabilityIdx",
"minValue", "maxValue", "enableStatus" })
public class IndicatorDefineExportDto implements Serializable
{
private static final long serialVersionUID = 4903249232957489027L;
@XmlElement (name = "indCode")
private String indCode;
@XmlElement (name = "indDescs")
private String indDescs;
@XmlElement (name = "indTypeCode")
private String indTypeCode;
@XmlElement (name = "monTableName")
private String monTableName;
@XmlElement (name = "monTableDescs")
private String monTableDescs;
@XmlElement (name = "monTableFieldName")
private String monTableFieldName;
@XmlElement (name = "monTableFieldDescs")
private String monTableFieldDescs;
@XmlElement (name = "validateType")
private String validateType;
@XmlElement (name = "validateDescs")
private String validateDescs;
@XmlJavaTypeAdapter (CDataAdapter.class)//这里是该属性需要加<![CDATA[]]>防止转换的注解
@XmlElement (name = "validateScript")
private String validateScript;
@XmlElement (name = "validateMethod")
private String validateMethod;
@XmlJavaTypeAdapter (CDataAdapter.class)//这里是该属性需要加<![CDATA[]]>防止转换的注解
@XmlElement (name = "relateTable")
private String relateTable;
@XmlElement (name = "relateScript")
private String relateScript;
@XmlElement (name = "stabilityIdx")
private String stabilityIdx;
@XmlElement (name = "minValue")
private String minValue;
@XmlElement (name = "maxValue")
private String maxValue;
@XmlElement (name = "enableStatus")
private String enableStatus;
//get,set方法省略
}

@XmlAccessorType (XmlAccessType.FIELD)
@XmlRootElement (name = "IndicatorDefineData")
@XmlType (propOrder =
{ "indicatorDefines" })
public class IndicatorDefines implements Serializable
{

/**
* serialVersionUID:TODO
*
* @since Ver 1.1
*/
private static final long serialVersionUID = 3140176739363502638L;

@XmlElementWrapper (name = "indicatorDefines")
@XmlElement (name = "indicatorDefine")
private List <IndicatorDefineExportDto> indicatorDefines;

使用

List <IndicatorDefineExportDto> indicatorDefineExportDtos = new ArrayList <IndicatorDefineExportDto> ();
IndicatorDefineExportDto indicatorDefineExportDto = new IndicatorDefineExportDto ();
//省略查询数据操作
//indicatorDefineInfos--查询到的数据
for (IndicatorDefine indicatorDefine : indicatorDefineInfos){
IndicatorDefineExportDto indicatorDefineExportDto = new IndicatorDefineExportDto ();
//省略...
//将indicatorDefine数据赋值到indicatorDefineExportDto 属性上
indicatorDefineExportDtos.add (indicatorDefineExportDto);
}
indicatorDefines.setIndicatorDefines (indicatorDefineExportDtos);
//生成xml内容
String xmlContent = JaxbUtil.convertToXml (indicatorDefines);
//以下省略...就是将文件传到前台