cuspay/src/main/java/com/emato/cuspay/util/XmlUtils.java

package com.emato.cuspay.util;

import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.XMLFilterImpl;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.transform.Source;
import javax.xml.transform.sax.SAXSource;
import java.io.File;
import java.io.StringReader;
import java.io.StringWriter;

/**
 * XML处理类
 *
 * @author Scott Chen
 * @date 2016/11/15
 */
public class XmlUtils {

    public static String toXML(Object obj, boolean format) throws Exception {
        try {
            JAXBContext context = JAXBContext.newInstance(obj.getClass());
            Marshaller marshaller = context.createMarshaller();

            //编码格式
            marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");

            // 是否格式化生成的xml串
            if (format) {
                marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
            }else{
                marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.FALSE);
            }

            // 是否省略xm头声明信息
            marshaller.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.FALSE);

            StringWriter writer = new StringWriter();
            marshaller.marshal(obj, writer);
            return writer.toString();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    public static String toXMLInFile(Object obj, String filePath, boolean format) throws Exception {
        try {
            JAXBContext context = JAXBContext.newInstance(obj.getClass());
            Marshaller marshaller = context.createMarshaller();

            //编码格式
            marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");

            // 是否格式化生成的xml串
            if (format) {
                marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
            }else{
                marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.FALSE);
            }

            // 是否省略xm头声明信息
            marshaller.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.FALSE);

            File file = new File(filePath);
            marshaller.marshal(obj, file);

            StringWriter writer = new StringWriter();
            marshaller.marshal(obj, writer);
            return writer.toString();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    @SuppressWarnings("unchecked")
    public static <T> T fromXML(String xmlStr, Class<T> valueType, boolean ignoreNs) throws Exception {
        try {
            JAXBContext context = JAXBContext.newInstance(valueType);
            Unmarshaller unmarshaller = context.createUnmarshaller();
            StringReader reader = new StringReader(xmlStr);

            //解析时,是否忽略命名空间
            if (ignoreNs) {
                /**
                 * 忽略命名空间
                 * 在序列化和反序列化时通过XMLFilterImpl的匿名实现类实现命名空间及xml节点名称的控制
                 */
                SAXParserFactory sax = SAXParserFactory.newInstance();
                //false:忽略命名空间
                sax.setNamespaceAware(false);
                XMLReader xmlReader = sax.newSAXParser().getXMLReader();

                XMLFilterImpl nsfFilter = new XMLFilterImpl() {
                    private boolean ignoreNamespace = false;

                    @Override
                    public void startDocument() throws SAXException {
                        super.startDocument();
                    }

                    @Override
                    public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
                        if (this.ignoreNamespace){
                            uri = "";
                        }

                        super.startElement(uri, localName, qName, atts);
                    }

                    @Override
                    public void endElement(String uri, String localName, String qName) throws SAXException {
                        if (this.ignoreNamespace){
                            uri = "";
                        }

                        super.endElement(uri, localName, localName);
                    }

                    @Override
                    public void startPrefixMapping(String prefix, String url) throws SAXException {
                        if (!this.ignoreNamespace){
                            super.startPrefixMapping("", url);
                        }
                    }
                };
                nsfFilter.setParent(xmlReader);

                Source source = new SAXSource(xmlReader, new InputSource(reader));
                return (T) unmarshaller.unmarshal(source);
            }
            return (T) unmarshaller.unmarshal(reader);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

}