Utils----XMLUtils将List＜Map＜＞＞数据写到xml文件以及读取xml文件到List

古城微笑少年丶 2023-01-23 09:53 83阅读 0赞

package koal.memory.encryptedblobstore.common;
    
    import org.dom4j.Document;
    import org.dom4j.DocumentException;
    import org.dom4j.DocumentHelper;
    import org.dom4j.Element;
    import org.dom4j.io.OutputFormat;
    import org.dom4j.io.SAXReader;
    import org.dom4j.io.XMLWriter;
    
    import java.io.*;
    import java.util.*;
    
    /**
     * 将List<Map<String,String>存储到XML文件中，
     * 以及将XML文件中的数据读取到List
     *
     * @Author lidonggui
     * @Date 2021/7/13 16:15
     * @Version 1.0
     */
    public class XMLUtils {
    
    
        /**
         * 将list数据写入到xml文件
         *
         * @param list
         * @param XMLPath xml文件路径
         * @return
         */
        public static void ListToXML(List<Map<String, String>> list, String XMLPath) {
            Document doc = DocumentHelper.createDocument();
    
    //        去除list中重复的map的key
            list = repeat(list);
    
            //添加元素和根节点
            doc = writeXML(doc, list);
    
            //实例化输出格式对象
    
            OutputFormat format = OutputFormat.createPrettyPrint();
    
            //设置输出编码
    
            format.setEncoding("UTF-8");
    
            //创建需要写入的File对象
    
            File file = new File(XMLPath);
    
            //生成XMLWriter对象，构造函数中的参数为需要输出的文件流和格式
    
            XMLWriter writer = null;
            try {
                writer = new XMLWriter(new FileOutputStream(file), format);
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
    
            //开始写入，write方法中包含上面创建的Document对象
    
            try {
                writer.write(doc);
            } catch (IOException e) {
                e.printStackTrace();
            }
            System.out.println("写入成功");
    
        }
    
        /**
         * 去除list中map的key重复的值，后添加的覆盖前添加的
         *
         * @param list 待去重的list
         * @return
         */
        public static List<Map<String, String>> repeat(List<Map<String, String>> list) {
            ListIterator<Map<String, String>> mapListIterator = list.listIterator();
    
            HashMap<String, String> map = new HashMap<>();
    //        将指针移动到末尾
            while (mapListIterator.hasNext()) {
                mapListIterator.next();
            }
    //        倒序遍历保证后添加的能保存下来
            while (mapListIterator.hasPrevious()) {
                Map<String, String> previous = mapListIterator.previous();
                String flag = (String) map.put(previous.get("key"), "tag");
                if (flag != null) {
                    mapListIterator.remove();
                }
            }
            return list;
        }
    
        /**
         * 增加节点
         *
         * @param doc
         * @param list
         * @return
         */
        public static Document writeXML(Document doc, List<Map<String, String>> list) {
    
            //增加根节点
    
            Element books = doc.addElement("stores");
    
            Iterator<Map<String, String>> iterator = list.iterator();
            int i = 0;
            while (iterator.hasNext()) {
                Map<String, String> next = iterator.next();
                Element store1 = books.addElement("store");
                store1.addAttribute("id", String.valueOf(i));
                for (Map.Entry<String, String> entry : next.entrySet()) {
    
                    Element key = store1.addElement(entry.getKey());
                    key.setText(entry.getValue());
    
                }
                i++;
            }
    
            return books.getDocument();
        }
    
    
        /**
         * 将xml文件读取到List
         *
         * @param XMLPath xml文件路径
         */
        public static List<Map<String, String>> XmlToList(String XMLPath) {
    
            List<Map<String, String>> list = new ArrayList<>();
            SAXReader reader = new SAXReader();
            File file = new File(XMLPath);
            Document document = null;
            try {
                document = reader.read(file);
            } catch (DocumentException e) {
                e.printStackTrace();
            }
            Element root = document.getRootElement();
            List<Element> childElements = root.elements();
            for (Element child : childElements) {
                Map map = new HashMap();
                //未知属性名情况下
                /*List<Attribute> attributeList = child.attributes();
                for (Attribute attr : attributeList) {
                    System.out.println(attr.getName() + ": " + attr.getValue());
                }*/
                //已知属性名情况下
    //            System.out.println("id: " + child.attributeValue("id"));
                //未知子元素名情况下
                /*List<Element> elementList = child.elements();
                for (Element ele : elementList) {
                    System.out.println(ele.getName() + ": " + ele.getText());
                }
                System.out.println();*/
                //已知子元素名的情况下
                map.put("key", child.elementText("key"));
    //            System.out.println("key" + child.elementText("key"));
                map.put("val", child.elementText("val"));
    //            System.out.println("val" + child.elementText("val"));
                list.add(map);
            }
            return list;
        }
    
    }