Java对象转xml，xml数据读取解析

喜欢ヅ旅行 2024-04-17 20:27 22阅读 0赞

## 部分依赖包 ##

<dependency>
                <groupId>dom4j</groupId>
                <artifactId>dom4j</artifactId>
                <version>1.1</version>
            </dependency>
    		<dependency>
                <groupId>org.apache.commons</groupId>
                <artifactId>commons-lang3</artifactId>
                <version>3.8.1</version>
            </dependency>
             <dependency>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-databind</artifactId>
                <version>2.8.4</version>
            </dependency>
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>1.2.4</version>
            </dependency>

## Java代码 ##

*  Java对象

import lombok.Data;
    
    import javax.xml.bind.annotation.XmlRootElement;
    
    @Data
    @XmlRootElement(name = "xml")
    //@XmlAccessorType(XmlAccessType.FIELD)
    public class User { 
    
        private String name;
    
        private String addr;
    
        private Integer age;
    }

*  工具封装

import javax.xml.bind.JAXBContext;
    import javax.xml.bind.JAXBException;
    import javax.xml.bind.Marshaller;
    import java.io.ByteArrayOutputStream;
    import java.io.IOException;
    
    public class JaxbUtil { 
    
        public static <T> String toXml(T xmlBean,Class<T> xmlClass, String encode) throws JAXBException{ 
            ByteArrayOutputStream output = new ByteArrayOutputStream();
            JAXBContext jc = JAXBContext.newInstance(xmlClass);
            Marshaller marshaller = jc.createMarshaller();
            marshaller.setProperty(Marshaller.JAXB_ENCODING, encode);
            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, false);
            marshaller.marshal(xmlBean, output);
            String xml = output.toString();
            try { 
                output.close();
            } catch (IOException e) { 
                e.printStackTrace();
                return xml;
            }
            return xml;
        }
    }

*  测试

import com.alibaba.fastjson.JSONArray;
    import com.alibaba.fastjson.JSONObject;
    import com.fasterxml.jackson.databind.ObjectMapper;
    import org.apache.commons.lang3.StringUtils;
    import org.dom4j.Document;
    import org.dom4j.DocumentException;
    import org.dom4j.DocumentHelper;
    import org.dom4j.Element;
    
    import javax.xml.bind.JAXBException;
    import java.io.IOException;
    import java.util.List;
    
    public class TestXml { 
        public static void main(String args[]) { 
            User user = new User();
            user.setName("测试人员");
            user.setAddr("hu");
            user.setAge(20);
            // 生成的xml数据
            String xml = "";
            try { 
                xml = JaxbUtil.toXml(user, User.class, "UTF-8");
                System.out.println("生成的xml数据格式: " + xml);
            } catch (JAXBException e) { 
                // 异常处理
                e.printStackTrace();
            }
            Document document = null;
            try { 
                document = DocumentHelper.parseText(xml);
            } catch (DocumentException e) { 
                // 异常处理
            }
            List<Element> list = document.getRootElement().elements();
            // xml 数据转成 JSONObject
            JSONObject jsonObject = new JSONObject();
            for (int i = 0; i < list.size(); i++) { 
                if (StringUtils.isNotBlank(list.get(i).getData().toString())) { 
                    // 判断参数是否是数据形式，否则用objectmapper 转换成实体类时会出现异常 `java.util.ArrayList` out of START_OBJECT token
                    if (list.get(i).getData().toString().startsWith("[")) { 
                        JSONArray array = JSONArray.parseArray(list.get(i).getData().toString());
                        jsonObject.put(list.get(i).getName(), array);
                    } else { 
                        jsonObject.put(list.get(i).getName(), list.get(i).getData());
                    }
                }
            }
            System.out.println("xml为json字符串： " + jsonObject.toJSONString());
           
           // json字符串转对象
            ObjectMapper mapper = new ObjectMapper();
            try { 
                User user2 = mapper.readValue(jsonObject.toString(), User.class);
                System.out.println("json字符串转对象：" + user2);
            } catch (IOException e) { 
                // 异常处理
                e.printStackTrace();
            }
        }
    
    }

*  附上测试打印结果

生成的xml数据格式: <?xml version="1.0" encoding="UTF-8" standalone="yes"?><xml><addr>hu</addr><age>20</age><name>测试人员</name></xml>
    xml为json字符串： { "name":"测试人员","addr":"hu","age":"20"}
    json字符串转对象：User(name=测试人员, addr=hu, age=20)