如何将XML转换为Java对象

怼烎@ 2021-06-12 15:16 845阅读 0赞

1.首先创建citylist.xml文件，放在resource目录下，文件内容如下：

<?xml version="1.0" encoding="UTF-8"?>
    <c c1="0">
      <d d1="101280101" d2="广州" d3="guangzhou" d4="广东"/>
      <d d1="101280102" d2="番禺" d3="panyu" d4="广东"/>
      <d d1="101280103" d2="从化" d3="conghua" d4="广东"/>
    </c>

2.创建与xml文件中的元素相对应的Bean，分别是CityList和City。  
CityList.java

/**
     * @desc 城市列表
     */
    @XmlRootElement(name="c")  //声明为xml的根元素c
    @XmlAccessorType(XmlAccessType.FIELD)  //通过字段来访问
    public class CityList implements Serializable {
    
        @XmlElement(name="d") //映射的xml元素
        private List<City> cityList;
    
        public List<City> getCityList() {
            return cityList;
        }
    
        public void setCityList(List<City> cityList) {
            this.cityList = cityList;
        }
    }

City.java

/**
     * @desc  城市信息 解析citylist.xml获取
     */
    @XmlRootElement(name="d")  //声明为xml的根元素d
    @XmlAccessorType(XmlAccessType.FIELD)  //通过字段来访问
    public class City implements Serializable {
    
        @XmlAttribute(name="d1") //映射的xml属性
        private String cityId;
        @XmlAttribute(name="d2")
        private String cityName;
        @XmlAttribute(name="d3")
        private String cityCode;
        @XmlAttribute(name="d4")
        private String province;
    
        public String getCityId() {
            return cityId;
        }
    
        public void setCityId(String cityId) {
            this.cityId = cityId;
        }
    
        public String getCityName() {
            return cityName;
        }
    
        public void setCityName(String cityName) {
            this.cityName = cityName;
        }
    
        public String getCityCode() {
            return cityCode;
        }
    
        public void setCityCode(String cityCode) {
            this.cityCode = cityCode;
        }
    
        public String getProvince() {
            return province;
        }
    
        public void setProvince(String province) {
            this.province = province;
        }
    }

3.读取xml文件，将其内容转换为字符串。

//读取xml文件
    Resource resource=new ClassPathResource("citylist.xml");
    BufferedReader reader=new BufferedReader(new InputStreamReader(resource.getInputStream(),"utf-8"));
    StringBuffer buffer=new StringBuffer();
    String line="";
    while((line=reader.readLine())!=null){
      buffer.append(line);
    }
    reader.close();

4.将CityList.class和buffer.toString()传入到以下方法的形参中，实现XML的对象转换。

/**
      * 将XML转为指定的POJO对象
      * @param clazz
      * @param xmlStr
      * @return
      */
    public static Object xmlStrToObject(Class<?> clazz,String xmlStr) throws Exception {
      Object xmlObject=null;
      Reader reader=null;
      JAXBContext context=JAXBContext.newInstance(clazz);
      //xml转为对象的接口
      Unmarshaller unmarshaller=context.createUnmarshaller();
      reader=new StringReader(xmlStr);
      xmlObject=unmarshaller.unmarshal(reader);
      if(null!=reader){
        reader.close();
      }
      return xmlObject;
    }