Java FastXML/Jackson 如何解析复杂的列表？

在 V2EX 上看到一个提问，如何把复杂的下面的数据解析出来

{
  "hosts": {
    "baidu.com": "127.0.0.1"
  },
  "servers": [
    {
      "address": "1.2.3.4",
      "port": 5353,
      "domains": [
        "domain:example.com"
      ]
    },
    "8.8.8.8",
    "8.8.4.4",
    "localhost"
  ],
  "clientIp": "1.2.3.4",
  "tag": "dns_inbound"
}

针对这种复杂的 JSON ，com.fasterxml.jackson.core.type.TypeReference 类终于是派上用场了。

都用 jackson 了, 当然是写一个类。

废话不多说，直接上代码

package cn.twle.demo;

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.File;
import java.util.List;
import java.util.Map;

public class MyClass {

    public static void main(String[] args) {

        try {
            ObjectMapper mapper = new ObjectMapper();
            TypeReference ref = new TypeReference<Response>(){};
            Response res = mapper.readValue(new File("serv.json"), ref);



            List<Server> servers = res.getServers();
            for(Server o : servers) {
                System.out.println(o.getAddress());
            }
        } catch(Exception e) {
            e.printStackTrace();
        }
    }
}


class Server {
    private String address;
    private Integer port = 0;
    private List<String> domains;

    public Server(){}

    public Server(String address) {
        this.address = address;
        this.port = 0;
        this.domains = null;
    }

    public Server(String address, Integer port,List<String> domains) {
        this.address = address;
        this.port = port;
        this.domains = domains;
    }

    public String getAddress() { return this.address;}
    public Integer getPort() { return this.port;}
    public List<String> getDomains(){ return this.domains;}


    public void setAddress(String address) { this.address = address;}
    public void setPort(Integer port) { this.port = port;}
    public void setDomains(List<String> domains) { this.domains = domains;}
}

class Response {
    private Map<String,String> hosts;
    private List<Server> servers;
    private String clientIp;
    private String tag;

    public Response(){}

    public Response(Map<String,String> hosts,
                       List<Server> servers,
                       String clientIp,
                       String tag) {
        this.hosts = hosts;
        this.servers = servers;
        this.clientIp = clientIp;
        this.tag = tag;
    }

    public String getTag() { return this.tag;}
    public String getClientIp() { return clientIp;}
    public List<Server> getServers() { return servers;}
    public Map<String,String> getHosts() { return hosts;}

    public void setTag(String tag) { this.tag = tag;}
    public void setClientIp(String clientIp) { this.clientIp = clientIp;}
    public void setHosts(Map<String,String> hosts) { this.hosts = hosts;}
    public void setServers(List<Server> servers) { this.servers = servers;}
}