com.fasterxml.jackson.dataformat.xml.XmlMapper把对象转换xml格式，属性放到标签＜＞里边

之前从没用过xml和对象相互转换，最近项目接了政府相关的。需要用xml格式数据进行相互转换。有些小问题，困扰了我一下下。

1.有些属性需要放到标签里边，有的需要放到标签子集。

2.xml需要加<?xml version="1.0" encoding="utf-8"?>头。

属性放到标签里边设置，isAttribute = true，代码如下：

package com.huateng.gongan.job.xml.bean;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.dataformat.xml.XmlMapper;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;

public class Add {
    @JacksonXmlProperty(localName = "key",isAttribute = true)
    private String key;
    @JacksonXmlProperty(localName = "value",isAttribute = true)
    private String value;

    public Add(String key, String value) {
        this.key = key;
        this.value = value;
    }

    public Add() {
    }

    public String getKey() {
        return key;
    }

    public void setKey(String key) {
        this.key = key;
    }

    public String getValue() {
        return value;
    }

    public void setValue(String value) {
        this.value = value;
    }

    public static void main(String[] args) throws JsonProcessingException {
        Add add = new Add("123","456");
        XmlMapper xmlMapper = new XmlMapper();
        String xml = xmlMapper.writeValueAsString(add);
        System.out.println(xml);
    }
}

输出样式：

<Add><key>123</key><value>456</value></Add>

属性放到标签子集设置，代码如下：

package com.huateng.gongan.job.xml.bean;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.dataformat.xml.XmlMapper;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;

public class Add {
    @JacksonXmlProperty(localName = "key")
    private String key;
    @JacksonXmlProperty(localName = "value")
    private String value;

    public Add(String key, String value) {
        this.key = key;
        this.value = value;
    }

    public Add() {
    }

    public String getKey() {
        return key;
    }

    public void setKey(String key) {
        this.key = key;
    }

    public String getValue() {
        return value;
    }

    public void setValue(String value) {
        this.value = value;
    }

    public static void main(String[] args) throws JsonProcessingException {
        Add add = new Add("123","456");
        XmlMapper xmlMapper = new XmlMapper();
        String xml = xmlMapper.writeValueAsString(add);
        System.out.println(xml);
    }
}

输出样式：

<add key="1" value="value1"/>

xml加<?xml version="1.0" encoding="utf-8"?>头，设置objectMapper.configure(ToXmlGenerator.Feature.WRITE_XML_DECLARATION, true)，代码如下：

        XmlMapper objectMapper = new XmlMapper();
        objectMapper.configure(ToXmlGenerator.Feature.WRITE_XML_DECLARATION, true);
        objectMapper.writeValueAsString(configuration);