解析xml利用反射機制解析到對應實體類實現方式之一

 根據業務需要，需要對獲取xml裏數據，下面是利用SAXParser進行實現的，代碼實現如下：

package tjs.utils.base.util;

import lombok.Data;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 * @project: base
 * @author: SJT
 * @date: 2019/5/20
 * @desc:
 */
@Data
public class SAXParserXml extends DefaultHandler {

    String value = null;
    Book book = null;
    Class clazz = null;
    String clazzName = null;
    List<Book> bookList = new ArrayList<>();
    {
        try {
            clazz = Class.forName("tjs.utils.base.util.Book");
            String name = clazz.getName();
            clazzName = toLowerCaseFirstOne(name.substring(name.lastIndexOf(".")+1));
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
    
    /**
    * @desc: 用來遍歷xml開始標籤
    * @author: SJT
    * @date: 2019/5/21
    * @param: [uri, localName, qName, attributes]
    * @return: void
    */
    @Override
    public void startElement(String uri, String localName, String qName,Attributes attributes) throws SAXException {
        super.startElement(uri, localName, qName, attributes);
        if (qName.equals(clazzName)) {
            //創建一個book對象
            book = new Book();
            for(int i=0;i<attributes.getLength();i++){
                setProperty(clazz.getDeclaredFields(),attributes.getQName(i));
            }
        }
    }

    /**
    * @desc: 用來遍歷xml結束標籤
    * @author: SJT
    * @date: 2019/5/21
    * @param: [uri, localName, qName]
    * @return: void
    */
    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        super.endElement(uri, localName, qName);
        Field[] fields = clazz.getDeclaredFields();
        setProperty(fields,qName);
        if (clazzName.equals(qName)) {
            bookList.add(book);
            book = null;
        }
    }

    public void setProperty(Field[] fields,String qName){
        Arrays.asList(fields).stream().forEach(x ->{
            if(qName.equals(x.getName())){
                try {
                    Method method = clazz.getDeclaredMethod("set"+toUpperCaseFirstOne(x.getName()),String.class);
                    method.setAccessible(true);
                    method.invoke(book,value);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
    * @desc: 獲取文本
    * @author: SJT
    * @date: 2019/5/21
    * @param: [ch, start, length]
    * @return: void
    */
    @Override
    public void characters(char[] ch, int start, int length)throws SAXException {
        super.characters(ch, start, length);
        value = new String(ch, start, length);
    }

    public  String toLowerCaseFirstOne(String s){
        return s.substring(0,1).toLowerCase()+s.substring(1);
    }


    public String toUpperCaseFirstOne(String s){
        return s.substring(0,1).toUpperCase()+s.substring(1);
    }

    public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException {
        SAXParserFactory factory = SAXParserFactory.newInstance();
        SAXParser parser = factory.newSAXParser();
        SAXParserXml parserXml = new SAXParserXml();
        parser.parse(SAXParserXml.class.getClass().getResource("/xml/book.xml").getFile(),parserXml);
        parserXml.getBookList().stream().forEach(x ->{
            System.out.println(x.getMonth());
        });
    }


}

ok，這樣即可，不到之處，不要介意~.~