利用ObjectMapper readValue()和泛型解决复杂json结构

 import com.dj.fss.vo.MessageListVO;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.databind.JsonMappingException;
 import com.fasterxml.jackson.databind.ObjectMapper;

 import java.io.IOException;
 import java.util.List;

 /**
  * ObjectMapper readValue()方法
  * 利用泛型解决复杂json结构
  * @JsonIgnoreProperties(ignoreUnknown = true) 没有实例化的属性不自动赋值 没有这个回报异常
  *
  * @param <T>
  */
 @JsonIgnoreProperties(ignoreUnknown = true)
 public class PageBean<T extends Object> {
     private List<MessageListVO> messageList;

     private pageinfo pageinfo;

     public PageBean.pageinfo getPageinfo() {
         return pageinfo;
     }

     public void setPageinfo(PageBean.pageinfo pageinfo) {
         this.pageinfo = pageinfo;
     }

     public List<MessageListVO> getMessageList() {
         return messageList;
     }

     public void setMessageList(List<MessageListVO> messageList) {
         this.messageList = messageList;
     }

     @JsonIgnoreProperties(ignoreUnknown = true)
     public class pageinfo{
         private int total;

         public int getTotal() {
             return total;
         }

         public void setTotal(int total) {
             this.total = total;
         }
     }

     private static String jsonString = "{\n" +
             "        \"messageList\": [\n" +
             "            {\n" +
             "                \"id\": \"7\",\n" +
             "                \"sendCompany\": \"广州机场\",\n" +
             "                \"recvCompany\": \"中国南航航空公司\",\n" +
             "                \"messageType\": \"1001\",\n" +
             "                \"sendTime\": \"2018-07-12 16:43:06\"\n" +
             "            },\n" +
             "            {\n" +
             "                \"id\": \"4\",\n" +
             "                \"sendCompany\": \"广州机场\",\n" +
             "                \"recvCompany\": \"中国南航航空公司\",\n" +
             "                \"messageType\": \"1002\",\n" +
             "                \"sendTime\": \"2018-07-12 15:49:02\"\n" +
             "            }\n" +
             "        ],\n" +
             "        \"pageinfo\": {\n" +
             "            \"pageNum\": 1,\n" +
             "            \"pageSize\": 3,\n" +
             "            \"size\": 2,\n" +
             "            \"startRow\": 1,\n" +
             "            \"endRow\": 2,\n" +
             "            \"total\": 2,\n" +
             "            \"pages\": 1,\n" +
             "            \"list\": null,\n" +
             "            \"prePage\": 0,\n" +
             "            \"nextPage\": 0,\n" +
             "            \"isFirstPage\": true,\n" +
             "            \"isLastPage\": true,\n" +
             "            \"hasPreviousPage\": false,\n" +
             "            \"hasNextPage\": false,\n" +
             "            \"navigatePages\": 8,\n" +
             "            \"navigatepageNums\": [\n" +
             "                1\n" +
             "            ],\n" +
             "            \"navigateFirstPage\": 1,\n" +
             "            \"navigateLastPage\": 1,\n" +
             "            \"firstPage\": 1,\n" +
             "            \"lastPage\": 1\n" +
             "        }\n" +
             "    }";

     public static void main(String[] args) throws JsonParseException, JsonMappingException, IOException {

         ObjectMapper mapper = new ObjectMapper();
         PageBean<MessageListVO> strPageBean = mapper.readValue(jsonString, PageBean.class);
         System.out.println(strPageBean.getMessageList().get(0));
         System.out.println(strPageBean.getMessageList().get(1));
         System.out.println(strPageBean.getPageinfo().getTotal());
     }

 }

结果：------------