xml 解析成对象，对象转成xml

痛定思痛。 2022-05-04 06:00 403阅读 0赞

此笔记留作备用，被解析的对象需要添加 @XmlRootElement 注解

**xml 解析成bean**

import javax.xml.bind.JAXBContext;
    import javax.xml.bind.JAXBException;
    import javax.xml.bind.Marshaller;
    import javax.xml.bind.Unmarshaller;
    import java.io.StringReader;
    import java.io.StringWriter;
    import java.nio.charset.Charset;
        /
        **
         * xml 解析成bean
         * @param xmlString
         * @param clazz
         * @param <T>
         * @return
         */
        public static final <T> T xml2bean(String xmlString, Class<T> clazz) {
            try {
                JAXBContext jaxbContext = JAXBContext.newInstance(clazz);
                Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
                return (T) unmarshaller.unmarshal(new StringReader(xmlString));
            } catch (JAXBException je) {
                logger.error("解析xml失败，失败的bean是: {}", clazz);
                logger.error("解析失败的xml是: {}", xmlString);
                throw new UnsupportedOperationException(je);
            }
        }

**bean 转成xml**

public static final String bean2xml(Object object, Charset charset) {
            String XML_DECLARATION_UTF8 = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>";
            String XML_DECLARATION_GBK = "<?xml version=\"1.0\" encoding=\"GBK\"?>";
            String result = "";
            JAXBContext context;
            try {
                context = JAXBContext.newInstance(object.getClass());
                Marshaller m = context.createMarshaller();
                m.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.TRUE);
                m.setProperty(Marshaller.JAXB_ENCODING, charset.name());
                StringWriter writer = new StringWriter();
                m.marshal(object, writer);
                result = writer.toString();
                result = (charset.name().equalsIgnoreCase("GBK") ? XML_DECLARATION_GBK : XML_DECLARATION_UTF8) + result;
                return result;
            } catch (JAXBException je) {
                logger.info("转换失败，失败的bean是: {}", object.toString());
                logger.info("转换失败的字符集是: {}", charset);
                throw new UnsupportedOperationException(je);
            }
        }

**测试**

public static void main(String[] args) {
    		Rule dr = new Rule();
    		dr.setId("1111");
    		dr.setlExp(null);
    		dr.setRelExp("sdsddsd");
    		String bean2xml = bean2xml(dr, Charset.forName("UTF-8"));
    		//<?xml version="1.0" encoding="UTF-8"?><Rule><id>1111</id><relExp>sdsddsd</relExp></Rule>
    		System.out.println(bean2xml);
    		
    		Rule xml2bean = xml2bean(bean2xml, DrlRule.class);
    		//Rule [id=1111, relExp=sdsddsd]
    		System.out.println(xml2bean);
    	}