数据格式转换，数据解析，实体类、json、map、xml

本文主要是介绍数据格式转换，数据解析，实体类、json、map、xml，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

       在做项目时，自己的系统经常需要与别的系统交互，实质上是数据的交互，这就牵涉到数据格式的转换，本篇总结一下常用的几种数据格式转换，主要有实体类与json、map、xml格式的相互转换。

       1、json与实体类互相转换

        工具类：     

package cn.usi.zhjt.pay.util;import java.io.IOException;import org.codehaus.jackson.map.ObjectMapper;
import org.json.JSONException;
import org.json.JSONObject;
/*** 实体类和JSON对象之间相互转化* 依赖包jackson-all-1.7.6.jar、jsoup-1.5.2.jar*/ 
public class JSONUtil {/*** 将json转化为实体POJO* @param jsonStr* @param obj* @return*/public static<T> Object JSONToObj(String jsonStr,Class<T> obj) {T t = null;try {ObjectMapper objectMapper = new ObjectMapper();t = objectMapper.readValue(jsonStr,obj);} catch (Exception e) {e.printStackTrace();}return t;}/*** 将实体POJO转化为JSON* @param obj* @return* @throws JSONException* @throws IOException*/public static<T> JSONObject objectToJson(T obj) throws JSONException, IOException {ObjectMapper mapper = new ObjectMapper();  // Convert object to JSON string  String jsonStr = "";try {jsonStr =  mapper.writeValueAsString(obj);} catch (IOException e) {throw e;}return new JSONObject(jsonStr);}}

       demo：

 

       json转换为实体类

 

   //respContent，json格式参数；ResContentQyWap，json格式参数对应的实体类ResContentQyWap resContentQy = (ResContentQyWap)JSONUtil.JSONToObj(respContent, ResContentQyWap.class);

      实体类转换成json格式字符串：

 

 

   //bean to jsonReqContentQy reqContentQy = new ReqContentQy();//reqContentQy为实体类，可通过set等把信息放入实体类，JSONObject是net.sf.json.JSONObjectJSONObject object = JSONObject.fromObject(reqContentQy);String request=object.toString();

      2、实体类与map相互转换

      工具类：

===================2019-06-03补充，处理类型转换异常======================

/*** 将一个 Map 对象转化为一个 JavaBean* @param clazz 要转化的类型* @param map 包含属性值的 map* @return 转化出来的 JavaBean 对象* @throws IntrospectionException* @throws IllegalAccessException* @throws InstantiationException* @throws InvocationTargetException*/public static <T> T mapToBean(Class<T> clazz, Map<?, ?> map) {T obj = null;try {BeanInfo beanInfo = Introspector.getBeanInfo(clazz);obj = clazz.newInstance(); // 创建 JavaBean 对象// 给 JavaBean 对象的属性赋值PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();for (int i = 0; i < propertyDescriptors.length; i++) {PropertyDescriptor descriptor = propertyDescriptors[i];String propertyName = descriptor.getName();if (map.containsKey(propertyName)) {// 下面一句可以 try 起来，这样当一个属性赋值失败的时候就不会影响其他属性赋值。Object value = map.get(propertyName);try {if ("".equals(value) || "null".equals(value)) {value = null;}Object[] args = new Object[1];args[0] = value;if((descriptor.getPropertyType().toString()).contains("Long") && args[0] != null){args[0] = Long.parseLong(args[0].toString());}if((descriptor.getPropertyType().toString()).contains("Integer") && args[0] != null){args[0] = Integer.parseInt(args[0].toString());}if((descriptor.getPropertyType().toString()).contains("Boolean") && args[0] != null){args[0] = Boolean.valueOf(args[0].toString());}if((descriptor.getPropertyType().toString()).contains("Date") && args[0] != null){try {SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");args[0] = df.parse(args[0].toString());}catch (Exception e){System.out.println("日期格式转换异常e："+e.getMessage());try {String date = args[0].toString().replace("Z", " UTC");SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS Z");args[0] = format.parse(date);}catch (Exception e1){System.out.println("日期格式转换异常e1："+e1.getMessage());}}}descriptor.getWriteMethod().invoke(obj, args);} catch (Exception e) {System.out.println("字段映射失败："+e.getMessage());}}}} catch (IllegalAccessException e) {System.out.println("实例化 JavaBean 失败："+e.getMessage());} catch (IntrospectionException e) {System.out.println("分析类属性失败："+e.getMessage());} catch (IllegalArgumentException e) {System.out.println("映射错误："+e.getMessage());} catch (InstantiationException e) {System.out.println("实例化 JavaBean 失败："+e.getMessage());}return (T) obj;}

=====================================================================

package com.ustcsoft.framework.util;import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.util.HashMap;
import java.util.Map;import org.apache.commons.beanutils.PropertyUtilsBean;public class MapConvertUtil {/*** 将JavaBean实体类转为map类型，然后返回一个map类型的值* @param obj，要转化的JavaBean 对象 * @return 需要返回的map*/public static Map<String, Object> beanToMap(Object obj) { Map<String, Object> params = new HashMap<String, Object>(0); try { PropertyUtilsBean propertyUtilsBean = new PropertyUtilsBean(); PropertyDescriptor[] descriptors = propertyUtilsBean.getPropertyDescriptors(obj); for (int i = 0; i < descriptors.length; i++) { String name = descriptors[i].getName(); if (!"class".equals(name)) { if(propertyUtilsBean.getNestedProperty(obj, name) != null){params.put(name, propertyUtilsBean.getNestedProperty(obj, name));}} } } catch (Exception e) { e.printStackTrace(); } return params; }/** * 将一个 Map 对象转化为一个 JavaBean * @param clazz 要转化的类型 * @param map 包含属性值的 map * @return 转化出来的 JavaBean 对象* @throws IntrospectionException* @throws IllegalAccessException* @throws InstantiationException* @throws InvocationTargetException*/  public static <T> T mapToBean(Class<T> clazz, Map<?, ?> map) {  T obj = null;  try {  BeanInfo beanInfo = Introspector.getBeanInfo(clazz);  obj = clazz.newInstance(); // 创建 JavaBean 对象  // 给 JavaBean 对象的属性赋值  PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();  for (int i = 0; i < propertyDescriptors.length; i++) {  PropertyDescriptor descriptor = propertyDescriptors[i];  String propertyName = descriptor.getName();  if (map.containsKey(propertyName)) {  // 下面一句可以 try 起来，这样当一个属性赋值失败的时候就不会影响其他属性赋值。  Object value = map.get(propertyName);  if ("".equals(value)) {  value = null;  }  Object[] args = new Object[1];  args[0] = value;  try {  descriptor.getWriteMethod().invoke(obj, args);  } catch (InvocationTargetException e) {  System.out.println("字段映射失败");  }  }  }  } catch (IllegalAccessException e) {  System.out.println("实例化 JavaBean 失败");  } catch (IntrospectionException e) {  System.out.println("分析类属性失败");  } catch (IllegalArgumentException e) {  System.out.println("映射错误");  } catch (InstantiationException e) {  System.out.println("实例化 JavaBean 失败");  }  return (T) obj;  }
}

补充：某种情况，获取的map的key全是大写，例如jdbc查询的结果的字段都是大写，这时需要做点变动

   

/*** 某种情况，获取的map的key全是大写，例如jdbc查询的结果的字段都是大写* 重写mapToBean方法，bean属性与key比较时转化为大写* @param clazz* @param map* @param <T>* @return*/public static <T> T mapToBeanUpcase(Class<T> clazz, Map<?, ?> map) {T obj = null;try {BeanInfo beanInfo = Introspector.getBeanInfo(clazz);obj = clazz.newInstance(); // 创建 JavaBean 对象// 给 JavaBean 对象的属性赋值PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();for (int i = 0; i < propertyDescriptors.length; i++) {PropertyDescriptor descriptor = propertyDescriptors[i];String propertyName = descriptor.getName();if (map.containsKey(propertyName.toUpperCase())) {//// 下面一句可以 try 起来，这样当一个属性赋值失败的时候就不会影响其他属性赋值。Object value = map.get(propertyName.toUpperCase());if ("".equals(value)) {value = null;}Object[] args = new Object[1];args[0] = value;try {descriptor.getWriteMethod().invoke(obj, args);} catch (InvocationTargetException e) {System.out.println("字段映射失败");}}}} catch (IllegalAccessException e) {System.out.println("实例化 JavaBean 失败");} catch (IntrospectionException e) {System.out.println("分析类属性失败");} catch (IllegalArgumentException e) {System.out.println("映射错误");} catch (InstantiationException e) {System.out.println("实例化 JavaBean 失败");}return (T) obj;}

 

  demo:      

 

        OnlineSigningInfo onlineSign = new OnlineSigningInfo();//onlineSign，实体类。requestMap，转化后的map格式参数Map<String, Object> requestMap = MapConvertUtil.beanToMap(onlineSign);//OnlineSigningInfo.class，要转化的类型 。requestMap，需要转换的map格式数据onlineSign= MapConvertUtil.mapToBean(OnlineSigningInfo.class, requestMap); 

       3、实体类与xml格式数据

        工具类;

 

package cn.usi.zhjt.pay.util;import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.List;
import java.util.Map;import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.TransformerException;import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;import com.sun.org.apache.xml.internal.serialize.OutputFormat;
import com.sun.org.apache.xml.internal.serialize.XMLSerializer;
import com.sun.org.apache.xpath.internal.XPathAPI;public class XMLConverUtil {/*** 遍历list，扩展子节点* @param sb，原有stringbuffer数据* @param list，需要转换的list格式数据* @throws Exception*/public static void getStringByList(StringBuffer sb, List list)throws Exception {if (list != null && list.size() != 0) {for (Object o : list) {sb.append("<");//根据自己的需要给自己的list设立节点名称sb.append("MyList");sb.append(">");//根据list内的数据，扩展子节点getStringProperty(sb, o);sb.append("</");sb.append("MyList");sb.append(">");}}}/*** 将字段key与值value，拼接成"<key>value</key>"形式* key可为String、Integer、int，此三种类型数据形成的对象和List* @param sb* @param vo* @throws Exception*/private static void getStringProperty(StringBuffer sb, Object vo)throws Exception {for (Field field : vo.getClass().getDeclaredFields()) {field.setAccessible(true);Object obj = field.get(vo);if (obj != null) {sb.append("<");sb.append(field.getName());sb.append(">");//根据字段的数据格式类型处理数据if ("java.util.List".equals(field.getType().getName())) {//处理list类型数据，扩展子节点getStringByList(sb, (List) obj);} else if ("java.lang.String".equals(field.getType().getName())|| "java.lang.Integer".equals(field.getType().getName())|| "int".equals(field.getType().getName())) {//String、Integer包装类和int型数据，直接设值sb.append(obj);} else {getStringProperty(sb, obj);}sb.append("</");sb.append(field.getName());sb.append(">");}}}private static DocumentBuilder getDocumentBuilder()throws ParserConfigurationException {DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();return dbf.newDocumentBuilder();}public static Document getDocument(InputSource inputSource)throws SAXException, IOException, ParserConfigurationException {return getDocumentBuilder().parse(inputSource);}/*** 将String类型数据转换为Document类型对象* @param text* @return* @throws SAXException* @throws IOException* @throws ParserConfigurationException*/public static Document getDOMByString(String text) throws SAXException,IOException, ParserConfigurationException {InputSource in = new InputSource(new StringReader(text));return getDocument(in);}public static Node string2Node(String xmlstr) throws SAXException,IOException, ParserConfigurationException {Document doc = string2Dom(xmlstr);return doc.getDocumentElement();}public static String dom2String(Document doc) throws IOException {doc.normalize();StringWriter wr = new StringWriter();OutputFormat of = new OutputFormat();of.setOmitXMLDeclaration(true);of.setIndenting(false);of.setPreserveSpace(true);XMLSerializer ser = new XMLSerializer(of);ser.setOutputCharStream(wr);ser.serialize(doc);return wr.toString();}public static Document string2Dom(String xml) throws SAXException,IOException, ParserConfigurationException {return getDOMByString(xml);}public static NodeList getNodes(Node doc, String xpath)throws TransformerException {return XPathAPI.selectNodeList(doc, xpath);}public static Node getSingleNode(Node doc, String xpath)throws TransformerException {return XPathAPI.selectSingleNode(doc, xpath);}public static Node createElement(Document doc, String name, String value) {Node element = doc.createElement(name);if (value != null)setNodeValue(element, value, true);return element;}public static void setNodeValue(Node node, String value)throws TransformerException {if (node == null) {return;}Node textNode = getSingleNode(node, "./text()");if (textNode != null) {textNode.setNodeValue(value);} else {textNode = node.getOwnerDocument().createTextNode(value);node.appendChild(textNode);}}public static void setNodeValue(Node node, String value, boolean replace) {if (node == null) {return;}Node textNode = node.getOwnerDocument().createTextNode(value);node.appendChild(textNode);}/*** Object转XML* xml里的根元素，根据自己的需要自己设置，编码格式也是* 子元素，从实体类里获取属性名和属性值写入* @param vo，需要转换的实体类* @return String，字符串* @throws Exception*/public static String getStringByObject(Object vo) throws Exception {StringBuffer sb = new StringBuffer();sb.append("<?xml version=\"1.0\" encoding=\"gb2312\"?>");//根据自己的需要设置根节点sb.append("<RequestContent>");getStringProperty(sb, vo);sb.append("</RequestContent>");return sb.toString();}/*** XML转Object* @param inputXML，需要转换的xml格式数据* @param object，需要转换成的实体类型* @return 返回需要格式的实体类对象* @throws Exception*/public static <T> T getObjectByString(String inputXML,Object object) throws Exception {//将String类型转换为Document类型对象Document doc = getDOMByString(inputXML);//获取第一个节点下面的所以子节点NodeList list = doc.getFirstChild().getChildNodes();Map<String, String> map = new HashMap<String, String>();//遍历节点，将Document对象转换成mapfor (int k = 0; k < list.getLength(); k++) {map.put(list.item(k).getNodeName().toUpperCase(), list.item(k).getTextContent());}for (Field field : object.getClass().getDeclaredFields()) {field.setAccessible(true);field.set(object,map.get(field.getName().toUpperCase()));}return (T)object;}}

           demo:

                ReqContent4001 reqContent4001 = new ReqContent4001();reqContent4001.setAddress("安徽合肥高新区");//通过set等设值//bean转换为xml格式数据String requestContentXml =XMLDomUtil.getStringByObject(reqContent4001);//xml格式数据转换为beanReqContent4001 result4001 = getObjectByString(requestContentXml, ReqContent4001.class);

          以上，实现了实体类与json、map、xml格式的相互转换。

 

 

 

 

 

 

 

 

 

  

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