前言：
我们在项目开发中，有时候调用别人提供的接口，接收到的数据是xml，这时候为了方便后续开发中的使用，需要解析xml并把数据转化成json，今天这篇文章就讲解下如何把xml转化成json，并在这个过程中容易出现的问题。
正文：
一、测试项目的搭建
1.需要引入的pom依赖
com.google.code.gson gson2.7 cn.hutool hutool-all4.0.9
2.xml映射的对象
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Programmer{
private String name;
private Integer age;
private String sex;
private String img;
}
3.转化的工具类
public class Xml2Json {
public static T convertToObject(String xml, Class cla){
JSonObject object = XML.toJSonObject(xml);
String jsonData = object.toString();
System.err.println(jsonData);
//截取字符串
String jsonObject = jsonData.substring(jsonData.indexOf(":")+1, jsonData.length()-1);
//将json格式的字符串转换成CertApplyRequest格式
Gson gson = new Gson();
T request = gson.fromJson(jsonObject, cla);
return request;
}
二、复现问题
1.测试代码
public static void main(String[] args){
String s="n" +
" man n" +
" 18n" +
"thttps://image.baidu.com/search/detail?ct=503316480&z=0&tn=baiduimagedetail&ipn=d&cl=2&cm=1&sc=0&lm=-1&ie=gb18030&pn=3&rn=1&di=99220&ln=30&word=%C5%ED%D3%DA%EA%CC&os=296869242,2380769407&cs=366539099,4208170291&objurl=http%3A%2F%2Fhbimg.b0.upaiyun.com%2Fd8241f63c93bb0f35d6f8557cff86cb524a9b6f71178f5-3NGIpU_fw658&bdtype=0&simid=3446695705,94736452&pi=0&adpicid=0&timingneed=0&spn=0&is=0,0&fr=ala&ala=1" +
"&alatpl=adress&pos=1&oriquery=%E5%BD%AD%E4%BA%8E%E6%99%8F&hs=2&xthttps=111111n" +
" n";
System.out.println(s);
Programmer programmer = Xml2Json.convertToObject(s, Programmer.class);
System.out.println(programmer.toString());
}
2.运行结果：报错啦！
Exception in thread "main" cn.hutool.json.JSONException: Missing ';' in XML entity: &z at 121 [character 59 line 4] at cn.hutool.json.JSONTokener.syntaxError(JSONTokener.java:373) at cn.hutool.json.XMLTokener.nextEntity(XMLTokener.java:107) at cn.hutool.json.XMLTokener.nextContent(XMLTokener.java:83) at cn.hutool.json.XML.parse(XML.java:171) at cn.hutool.json.XML.parse(XML.java:185) at cn.hutool.json.XML.toJSonObject(XML.java:232) at cn.hutool.json.XML.toJSonObject(XML.java:214) at com.model.Xml2Json.convertToObject(Xml2Json.java:15) at com.model.Xml2Json.main(Xml2Json.java:46) Process finished with exit code 1 man 18 https://image.baidu.com/search/detail?ct=503316480&z=0&tn=baiduimagedetail&ipn=d&cl=2&cm=1&sc=0&lm=-1&ie=gb18030&pn=3&rn=1&di=99220&ln=30&word=%C5%ED%D3%DA%EA%CC&os=296869242,2380769407&cs=366539099,4208170291&objurl=http%3A%2F%2Fhbimg.b0.upaiyun.com%2Fd8241f63c93bb0f35d6f8557cff86cb524a9b6f71178f5-3NGIpU_fw658&bdtype=0&simid=3446695705,94736452&pi=0&adpicid=0&timingneed=0&spn=0&is=0,0&fr=ala&ala=1&alatpl=adress&pos=1&oriquery=%E5%BD%AD%E4%BA%8E%E6%99%8F&hs=2&xthttps=111111
3.分析结果
一般出现上面的异常，基本都是xml里的格式或者有特殊字符才报错的，所以我们可以看下我们的xml里的参数是否有特殊字符。可以看到img标签里的图片地址有特殊字符&，所以这时候我们只要把&进行转义，就可以啦。
三、解决问题
1.修改后的测试代码：
public static void main(String[] args){
String s="n" +
" man n" +
" 18n" +
"thttps://image.baidu.com/search/detail?ct=503316480&z=0&tn=baiduimagedetail&ipn=d&cl=2&cm=1&sc=0&lm=-1&ie=gb18030&pn=3&rn=1&di=99220&ln=30&word=%C5%ED%D3%DA%EA%CC&os=296869242,2380769407&cs=366539099,4208170291&objurl=http%3A%2F%2Fhbimg.b0.upaiyun.com%2Fd8241f63c93bb0f35d6f8557cff86cb524a9b6f71178f5-3NGIpU_fw658&bdtype=0&simid=3446695705,94736452&pi=0&adpicid=0&timingneed=0&spn=0&is=0,0&fr=ala&ala=1" +
"&alatpl=adress&pos=1&oriquery=%E5%BD%AD%E4%BA%8E%E6%99%8F&hs=2&xthttps=111111n" +
" n";
String s1 = s.replaceAll("&", "&");
System.out.println(s);
System.out.println(s1);
Programmer programmer = Xml2Json.convertToObject(s1, Programmer.class);
System.out.println(programmer.toString());
}
2.运行结果：xml转化json成功。
man 18 https://image.baidu.com/search/detail?ct=503316480&z=0&tn=baiduimagedetail&ipn=d&cl=2&cm=1&sc=0&lm=-1&ie=gb18030&pn=3&rn=1&di=99220&ln=30&word=%C5%ED%D3%DA%EA%CC&os=296869242,2380769407&cs=366539099,4208170291&objurl=http%3A%2F%2Fhbimg.b0.upaiyun.com%2Fd8241f63c93bb0f35d6f8557cff86cb524a9b6f71178f5-3NGIpU_fw658&bdtype=0&simid=3446695705,94736452&pi=0&adpicid=0&timingneed=0&spn=0&is=0,0&fr=ala&ala=1&alatpl=adress&pos=1&oriquery=%E5%BD%AD%E4%BA%8E%E6%99%8F&hs=2&xthttps=111111{"student":{"img":"https://image.baidu.com/search/detail?ct=503316480&z=0&tn=baiduimagedetail&ipn=d&cl=2&cm=1&sc=0&lm=-1&ie=gb18030&pn=3&rn=1&di=99220&ln=30&word=%C5%ED%D3%DA%EA%CC&os=296869242,2380769407&cs=366539099,4208170291&objurl=http%3A%2F%2Fhbimg.b0.upaiyun.com%2Fd8241f63c93bb0f35d6f8557cff86cb524a9b6f71178f5-3NGIpU_fw658&bdtype=0&simid=3446695705,94736452&pi=0&adpicid=0&timingneed=0&spn=0&is=0,0&fr=ala&ala=1&alatpl=adress&pos=1&oriquery=%E5%BD%AD%E4%BA%8E%E6%99%8F&hs=2&xthttps=111111","sex":"man","name":"zhangsan","age":18}} Xml2Json.Programmer(name=zhangsan, age=18, sex=man, img=https://image.baidu.com/search/detail?ct=503316480&z=0&tn=baiduimagedetail&ipn=d&cl=2&cm=1&sc=0&lm=-1&ie=gb18030&pn=3&rn=1&di=99220&ln=30&word=%C5%ED%D3%DA%EA%CC&os=296869242,2380769407&cs=366539099,4208170291&objurl=http%3A%2F%2Fhbimg.b0.upaiyun.com%2Fd8241f63c93bb0f35d6f8557cff86cb524a9b6f71178f5-3NGIpU_fw658&bdtype=0&simid=3446695705,94736452&pi=0&adpicid=0&timingneed=0&spn=0&is=0,0&fr=ala&ala=1&alatpl=adress&pos=1&oriquery=%E5%BD%AD%E4%BA%8E%E6%99%8F&hs=2&xthttps=111111) man 18 https://image.baidu.com/search/detail?ct=503316480&z=0&tn=baiduimagedetail&ipn=d&cl=2&cm=1&sc=0&lm=-1&ie=gb18030&pn=3&rn=1&di=99220&ln=30&word=%C5%ED%D3%DA%EA%CC&os=296869242,2380769407&cs=366539099,4208170291&objurl=http%3A%2F%2Fhbimg.b0.upaiyun.com%2Fd8241f63c93bb0f35d6f8557cff86cb524a9b6f71178f5-3NGIpU_fw658&bdtype=0&simid=3446695705,94736452&pi=0&adpicid=0&timingneed=0&spn=0&is=0,0&fr=ala&ala=1&alatpl=adress&pos=1&oriquery=%E5%BD%AD%E4%BA%8E%E6%99%8F&hs=2&xthttps=111111
总结：
xml转化josn报错的时候基本上都是xml的格式不正确或者是数据里有特殊字符，对了xml里的标签头不用转义，转义后反而会报错，原因在源码里。
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