Java读取多层级xml文件

た入场券 2022-07-14 09:29 210阅读 0赞

最近在做国际客服北京职场的项目，需要提供一个接口服务端的能力，也就是需要开发一个http+xml的协议，入参和出参均为Map格式，各系统间的请求或应答是以xml格式封装的。在将返回报文（xml）解析为Map输出时遇到一个难点：Java对于多层级xml的解析。现以一个客户资料查询接口为例将解析过程记录如下：

返回xml报文的简化形式：

<?xml version="1.0" encoding="UTF-8"?>
    <ROOT>
          <HEAD>
                <ORIGIN_DOMAIN>kefuxitongbianma</ORIGIN_DOMAIN>
                <HOME_DOMAIN>CUGCRM</HOME_DOMAIN>
                <ACTION_CODE>1</ACTION_CODE>
                <BUSI_CODE>QUERYCUST</BUSI_CODE>
                <TRANS_ID>20160220160635123456</TRANS_ID>
                <RET_CODE>0000</RET_CODE>
                <RET_MSG>success</RET_MSG>
          </HEAD>
          <BODY>
                <TOTAL_RECORDS>20</TOTAL_RECORDS>
                <TOTAL_PAGE>10</TOTAL_PAGE>
                <CURRENT_PAGE>1</CURRENT_PAGE>
                <CUSTINFOLIST>
                      <CUSTINFO>
                            <CUST_TYPE>001</CUST_TYPE>
                            <VIP_FLAG>true</VIP_FLAG>
                      </CUSTINFO>
                      <CUSTINFO>
                            <CUST_TYPE>002</CUST_TYPE>
                            <VIP_FLAG>false</VIP_FLAG>
                      </CUSTINFO>
                      <CUSTINFO>
                            <CUST_TYPE>003</CUST_TYPE>
                            <VIP_FLAG>false</VIP_FLAG>
                      </CUSTINFO>
                </CUSTINFOLIST>
          </BODY>
    </ROOT>

import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    import java.util.Set;
    import net.sf.json.JSONObject;
    import org.apache.log4j.Logger;
    import org.dom4j.Document;
    import org.dom4j.DocumentException;
    import org.dom4j.DocumentHelper;
    import org.dom4j.Element;
    import org.dom4j.Namespace;
    import org.dom4j.QName;
    /**
     * 解析xml的工具类
     * 1、将多层级xml解析为Map
     * 2、将多层级xml解析为Json
     *
     * @author lmb
     *
     */
    public class ParseXmlUtil {
          
          public static Logger logger = Logger.getLogger(ParseXmlUtil.class);
          public static void main(String[] args) { 
                  // 获取一个xml文件 
                  String textFromFile = MyXmlUtil.XmlToString();
                  //将xml解析为Map
                  Map resultMap = xml2map(textFromFile);
                  //将xml解析为Json
                  String resultJson = xml2Json(textFromFile);
          } 
          
          
          /**
           * 将xml格式响应报文解析为Json格式
           * @param responseXmlTemp
           * @return
           */
          public static String xml2Json(String responseXmlTemp) {
                Document doc = null;
                try {
                      doc = DocumentHelper.parseText(responseXmlTemp);
                } catch (DocumentException e) {
                      logger.error("parse text error : " + e);
                }
                Element rootElement = doc.getRootElement();
                Map<String,Object> mapXml = new HashMap<String,Object>();
                element2Map(mapXml,rootElement);
                String jsonXml = JSONObject.fromObject(mapXml).toString();
                System.out.println("Json >>> " + jsonXml);
                return jsonXml;
          }
          /**
           * 将xml格式响应报文解析为Map格式
           * @param responseXmlTemp
           * @param thirdXmlServiceBean
           * @return
           * @throws DocumentException
           */
          public static Map<String, Object> xml2map(String responseXmlTemp) {
                Document doc = null;
                try {
                      doc = DocumentHelper.parseText(responseXmlTemp);
                } catch (DocumentException e) {
                      logger.error("parse text error : " + e);
                }
                Element rootElement = doc.getRootElement();
                Map<String,Object> mapXml = new HashMap<String,Object>();
                element2Map(mapXml,rootElement);
                System.out.println("Map >>> " + mapXml);
                return mapXml;
          }
          /**
           * 使用递归调用将多层级xml转为map
           * @param map
           * @param rootElement
           */
          public static void element2Map(Map<String, Object> map, Element rootElement) {
                
                //获得当前节点的子节点
                List<Element> elements = rootElement.elements();
                if (elements.size() == 0) {
                      //没有子节点说明当前节点是叶子节点，直接取值
                      map.put(rootElement.getName(),rootElement.getText());
                }else if (elements.size() == 1) {
                      //只有一个子节点说明不用考虑list的情况，继续递归
                      Map<String,Object> tempMap = new HashMap<String,Object>();
                      element2Map(tempMap,elements.get(0));
                      map.put(rootElement.getName(),tempMap);
                }else {
                      //多个子节点的话就要考虑list的情况了，特别是当多个子节点有名称相同的字段时
                      Map<String,Object> tempMap = new HashMap<String,Object>();
                      for (Element element : elements) {
                            tempMap.put(element.getName(),null);
                      }
                      Set<String> keySet = tempMap.keySet();
                      for (String string : keySet) {
                            Namespace namespace = elements.get(0).getNamespace();
                            List<Element> sameElements = rootElement.elements(new QName(string,namespace));
                            //如果同名的数目大于1则表示要构建list
                            if (sameElements.size() > 1) {
                                  List<Map> list = new ArrayList<Map>();
                                  for(Element element : sameElements){
                                        Map<String,Object> sameTempMap = new HashMap<String,Object>();
                                        element2Map(sameTempMap,element);
                                        list.add(sameTempMap);
                                  }
                                  map.put(string,list);
                            }else {
                                  //同名的数量不大于1直接递归
                                  Map<String,Object> sameTempMap = new HashMap<String,Object>();
                                  element2Map(sameTempMap,sameElements.get(0));
                                  map.put(string,sameTempMap);
                            }
                      }
                }
          }
    }

**xml文件读取工具类：**

import java.io.File;
    import java.io.IOException;
    import java.io.StringWriter;
    import org.jdom.Document;
    import org.jdom.input.SAXBuilder;
    import org.jdom.output.Format;
    import org.jdom.output.XMLOutputter;
    /**
     * 读取一个xml文件返回string
     * @author lmb 
     *
     */
    public class MyXmlUtil {
          /**
           * 加载xml文件
           * @return Document
           */
          public static Document load(){
                Document document=null; 
            String url="E://2.xml"; 
            try { 
                SAXBuilder reader = new SAXBuilder();  
                document=reader.build(new File(url)); 
           } catch (Exception e) { 
                e.printStackTrace(); 
           } 
            return document;
          }
          
          /**
           * 将xml文件转换为String串
           * @return
           */
          public static String XmlToString(){
                Document document=null; 
            document=load(); 
             
            Format format =Format.getPrettyFormat();     
            format.setEncoding("UTF-8");//设置编码格式  
             
            StringWriter out=null; //输出对象 
            String sReturn =""; //输出字符串 
            XMLOutputter outputter =new XMLOutputter();  
            out=new StringWriter();  
            try { 
               outputter.output(document,out); 
            } catch (IOException e) { 
               e.printStackTrace(); 
            }  
            sReturn=out.toString();  
            return sReturn; 
        } 
    }

**控制台打印结果：**

Map >>> {BODY={TOTAL_RECORDS={TOTAL_RECORDS=20}, CUSTINFOLIST={CUSTINFO=[{CUST_TYPE={CUST_TYPE=001}, VIP_FLAG={VIP_FLAG=true}}, {CUST_TYPE={CUST_TYPE=002}, VIP_FLAG={VIP_FLAG=false}}, {CUST_TYPE={CUST_TYPE=003}, VIP_FLAG={VIP_FLAG=false}}]}, TOTAL_PAGE={TOTAL_PAGE=10}, CURRENT_PAGE={CURRENT_PAGE=1}}, HEAD={ACTION_CODE={ACTION_CODE=1}, ORIGIN_DOMAIN={ORIGIN_DOMAIN=kefuxit}, BUSI_CODE={BUSI_CODE=QUERYCUST}, HOME_DOMAIN={HOME_DOMAIN=CUGCRM}, TRANS_ID={TRANS_ID=20160220160635123456}, RET_MSG={RET_MSG=success}, RET_CODE={RET_CODE=0000}}}
    
    Json >>> {"BODY":{"TOTAL_RECORDS":{"TOTAL_RECORDS":"20"},"CUSTINFOLIST":{"CUSTINFO":[{"CUST_TYPE":{"CUST_TYPE":"001"},"VIP_FLAG":{"VIP_FLAG":"true"}},{"CUST_TYPE":{"CUST_TYPE":"002"},"VIP_FLAG":{"VIP_FLAG":"false"}},{"CUST_TYPE":{"CUST_TYPE":"003"},"VIP_FLAG":{"VIP_FLAG":"false"}}]},"TOTAL_PAGE":{"TOTAL_PAGE":"10"},"CURRENT_PAGE":{"CURRENT_PAGE":"1"}},"HEAD":{"ACTION_CODE":{"ACTION_CODE":"1"},"ORIGIN_DOMAIN":{"ORIGIN_DOMAIN":"kefuxit"},"BUSI_CODE":{"BUSI_CODE":"QUERYCUST"},"HOME_DOMAIN":{"HOME_DOMAIN":"CUGCRM"},"TRANS_ID":{"TRANS_ID":"20160220160635123456"},"RET_MSG":{"RET_MSG":"success"},"RET_CODE":{"RET_CODE":"0000"}}}

**格式化之后的结果如下：**

map :
    {
        BODY={
            TOTAL_RECORDS={TOTAL_RECORDS=20},
            CUSTINFOLIST={
                CUSTINFO=[
                    {
                        CUST_TYPE={CUST_TYPE=001},
                        VIP_FLAG={VIP_FLAG=true}
                    },
                    {
                        CUST_TYPE={CUST_TYPE=002},
                        VIP_FLAG={VIP_FLAG=false}
                    },
                    {
                        CUST_TYPE={CUST_TYPE=003},
                        VIP_FLAG={VIP_FLAG=false}
                    }
                ]
            },
            TOTAL_PAGE={TOTAL_PAGE=10},
            CURRENT_PAGE={CURRENT_PAGE=1}
        },
        HEAD={
            ACTION_CODE={ACTION_CODE=1},
            ORIGIN_DOMAIN={ORIGIN_DOMAIN=kefuxit},
            BUSI_CODE={BUSI_CODE=QUERYCUST},
            HOME_DOMAIN={HOME_DOMAIN=CUGCRM},
            TRANS_ID={TRANS_ID=20160220160635123456},
            RET_MSG={RET_MSG=success},
            RET_CODE={RET_CODE=0000}
        }
    }
    
    Json:
    {
        "BODY":{
            "TOTAL_RECORDS":{"TOTAL_RECORDS":"20"},
            "CUSTINFOLIST":{
                "CUSTINFO":[
                    {
                        "CUST_TYPE":{"CUST_TYPE":"001"},
                        "VIP_FLAG":{"VIP_FLAG":"true"}
                    },
                    {
                        "CUST_TYPE":{"CUST_TYPE":"002"},
                        "VIP_FLAG":{"VIP_FLAG":"false"}
                    },
                    {
                        "CUST_TYPE":{"CUST_TYPE":"003"},
                        "VIP_FLAG":{"VIP_FLAG":"false"}
                    }
                ]
            },
            "TOTAL_PAGE":{"TOTAL_PAGE":"10"},
            "CURRENT_PAGE":{"CURRENT_PAGE":"1"}
        },
        "HEAD":{
            "ACTION_CODE":{"ACTION_CODE":"1"},
            "ORIGIN_DOMAIN":{"ORIGIN_DOMAIN":"kefuxit"},
            "BUSI_CODE":{"BUSI_CODE":"QUERYCUST"},
            "HOME_DOMAIN":{"HOME_DOMAIN":"CUGCRM"},
            "TRANS_ID":{"TRANS_ID":"20160220160635123456"},
            "RET_MSG":{"RET_MSG":"success"},
            "RET_CODE":{"RET_CODE":"0000"}
        }
    }