Plusieurs conversions simples de collections d'objets complexes dans la bibliothèque Jackson de Java

Cet article présente principalement plusieurs conversions simples de collections d'objets complexes dans la bibliothèque Jackson de Java. Il a une très bonne valeur de référence. Jetons-y un coup d'œil avec l'éditeur ci-dessous

Sans plus tarder, veuillez regarder le code :

package com; 
import java.io.BufferedReader; 
import java.io.ByteArrayInputStream; 
import java.io.IOException; 
import java.io.InputStreamReader; 
import java.util.List; 
import com.fasterxml.jackson.core.JsonParseException; 
import com.fasterxml.jackson.databind.JavaType; 
import com.fasterxml.jackson.databind.JsonMappingException; 
import com.fasterxml.jackson.databind.ObjectMapper; 
/** 
 * jackson 复杂 对象集合 的几种简单转换 
 * @author lenovo 
 * 
 * @param <T> 
 */ 
public class Main<T> 
{ 
 static ObjectMapper mapper = new ObjectMapper(); 
 public static void main(String[] args) throws JsonParseException, 
   JsonMappingException, IOException 
 { 
  String josn = "{\"UserID\":1,\"LoginName\":\"唐工\",\"Truename\":\"超级\",\"Nickname\":null,\"LoginPwd\":\"E10ADC3949BA59ABBE56E057F20F883E\",\"QQ\":\"\",\"Phone\":\"\",\"Email\":null,\"Remark\":\"\",\"Account_Non_Locked\":0,\"Telelephone\":null,\"IsDelete\":0}"; 
  User u = mapper.readValue(josn, User.class); 
  // User u=new Main<User>().jsonStreamConverObject(josn, User.class); 
  System.out.println("转对象:" + u); 
  // 转集合 
  String josn2 = "[{\"UserID\":1,\"LoginName\":\"唐工\",\"Truename\":\"超级\",\"Nickname\":null,\"LoginPwd\":\"E10ADC3949BA59ABBE56E057F20F883E\",\"QQ\":\"\",\"Phone\":\"\",\"Email\":null,\"Remark\":\"\",\"Account_Non_Locked\":0,\"Telelephone\":null,\"IsDelete\":0}]"; 
  JavaType javaType = mapper.getTypeFactory().constructParametricType( 
    List.class, User.class); 
  List<User> me = mapper.readValue(josn2, javaType); 
  System.out.println("转集合me:" + me); 
  // 对象里有 集合 转换 
  String josn3 = "{\"UserID\":1,\"LoginName\":\"唐工\",\"Truename\":\"超级\",\"Nickname\":null,\"LoginPwd\":\"E10ADC3949BA59ABBE56E057F20F883E\",\"QQ\":\"\",\"Phone\":\"\",\"Email\":null,\"Remark\":\"\",\"Account_Non_Locked\":0,\"Telelephone\":null,\"IsDelete\":0,\"RoleList\":[{\"Roleid\":0,\"Name\":\"超级管理员\",\"Show_Name\":\"超级管理员\",\"Remark\":null,\"Type\":1}]}"; 
  User u3 = mapper.readValue(josn3, User.class); // 简单方式 
  // User u3=new Main<User>().jsonConverObject(josn3, User.class); 流方式 
  System.out.println("转对象里有集合u3:" + u3); 
  // 集合 对象 集合 转换 
  String josn4 = "[{\"UserID\":1,\"LoginName\":\"唐工\",\"Truename\":\"超级\",\"Nickname\":null,\"LoginPwd\":\"E10ADC3949BA59ABBE56E057F20F883E\",\"QQ\":\"\",\"Phone\":\"\",\"Email\":null,\"Remark\":\"\",\"Account_Non_Locked\":0,\"Telelephone\":null,\"IsDelete\":0,\"RoleList\":[{\"Roleid\":0,\"Name\":\"超级管理员\",\"Show_Name\":\"超级管理员\",\"Remark\":null,\"Type\":1}]},{\"UserID\":2,\"LoginName\":\"唐工\",\"Truename\":\"超级\",\"Nickname\":null,\"LoginPwd\":\"E10ADC3949BA59ABBE56E057F20F883E\",\"QQ\":\"\",\"Phone\":\"\",\"Email\":null,\"Remark\":\"\",\"Account_Non_Locked\":0,\"Telelephone\":null,\"IsDelete\":0,\"RoleList\":[{\"Roleid\":0,\"Name\":\"超级管理员\",\"Show_Name\":\"超级管理员\",\"Remark\":null,\"Type\":1}]}]"; 
  JavaType javaType4 = mapper.getTypeFactory().constructParametricType( 
    List.class, User.class); 
  List<User> list = mapper.readValue(josn4, javaType4); 
  System.out.println("集合里是对象 对象里有集合转换:" + list); 
 } 
 /*** 
  * 转对象 
  * @param josn 
  * @param clz 
  * @return 
  */ 
 public T jsonStreamConverObject(String josn, Class<T> clz) 
 { 
  T t = null; 
  // ObjectMapper jacksonMapper = new ObjectMapper(); 
  InputStreamReader in = new InputStreamReader(new ByteArrayInputStream( 
    josn.getBytes())); 
  BufferedReader streamReader = new BufferedReader(in); 
  StringBuilder buff = new StringBuilder(); 
  String inputStr; 
  try 
  { 
   while ((inputStr = streamReader.readLine()) != null) 
    buff.append(inputStr); 
   // ObjectMapper mapper = new ObjectMapper(); 
   t = mapper.readValue(buff.toString(), clz); 
  } catch (IOException e) 
  { 
   e.printStackTrace(); 
  } 
  return t; 
 } 
 /*** 
  * 转对象 
  * @param josn 
  * @param clz 
  * @return 
  */ 
 public T jsonConverObject(String josn, Class<T> clz) 
 { 
  T t = null; 
  try 
  { 
   t = mapper.readValue(josn, clz); 
  } catch (JsonParseException e) 
  { 
   e.printStackTrace(); 
  } catch (JsonMappingException e) 
  { 
   e.printStackTrace(); 
  } catch (IOException e) 
  { 
   e.printStackTrace(); 
  } 
  return t; 
 } 
 /** 
  * 转集合 
  * @param josn 
  * @param clz 
  * @return 
  */ 
 public List<T> jsonConverList(String josn, Class<T> clz) 
 { 
  List<T> me = null; 
  try 
  { 
   // jacksonMapper 
   // .disable(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES); 
   // jacksonMapper.enableDefaultTyping(); 
   // jacksonMapper.setVisibility(JsonMethod.FIELD,JsonAutoDetect.Visibility.ANY); 
   // jacksonMapper.configure(SerializationConfig.Feature.INDENT_OUTPUT, 
   // false);//格式化 
   // jacksonMapper.setSerializationInclusion(JsonSerialize.Inclusion.NON_NULL); 
   // jacksonMapper.configure(SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS, 
   // false); 
   JavaType javaType = mapper.getTypeFactory() 
     .constructParametricType(List.class, clz);// clz.selGenType().getClass() 
   me = mapper.readValue(josn, javaType); 
  } catch (JsonParseException e) 
  { 
   e.printStackTrace(); 
  } catch (JsonMappingException e) 
  { 
   e.printStackTrace(); 
  } catch (IOException e) 
  { 
   e.printStackTrace(); 
  } 
  return me; 
 } 
} 
/** 
 * output: 
 * 转对象:User [UserID=1, LoginName=唐工, Truename=超级, Nickname=null, LoginPwd=E10ADC3949BA59ABBE56E057F20F883E, QQ=, Phone=, Email=null, Remark=, Account_Non_Locked=0, Telelephone=null, Indate=null, IsDelete=0, RoleList=null] 
 * 转集合me:[User [UserID=1, LoginName=唐工, Truename=超级, Nickname=null, LoginPwd=E10ADC3949BA59ABBE56E057F20F883E, QQ=, Phone=, Email=null, Remark=, Account_Non_Locked=0, Telelephone=null, Indate=null, IsDelete=0, RoleList=null]] 
 * 转对象里有集合u3:User [UserID=1, LoginName=唐工, Truename=超级, Nickname=null, LoginPwd=E10ADC3949BA59ABBE56E057F20F883E, QQ=, Phone=, Email=null, Remark=, Account_Non_Locked=0, Telelephone=null, Indate=null, IsDelete=0, RoleList=[Role [Roleid=0, Name=超级管理员, Show_Name=超级管理员, Remark=null, Type=1]]] 
 * 集合里是对象 对象里有集合转换:[User [UserID=1, LoginName=唐工, Truename=超级, Nickname=null, LoginPwd=E10ADC3949BA59ABBE56E057F20F883E, QQ=, Phone=, Email=null, Remark=, Account_Non_Locked=0, Telelephone=null, Indate=null, IsDelete=0, RoleList=[Role [Roleid=0, Name=超级管理员, Show_Name=超级管理员, Remark=null, Type=1]]], User [UserID=2, LoginName=唐工, Truename=超级, Nickname=null, LoginPwd=E10ADC3949BA59ABBE56E057F20F883E, QQ=, Phone=, Email=null, Remark=, Account_Non_Locked=0, Telelephone=null, Indate=null, IsDelete=0, RoleList=[Role [Roleid=0, Name=超级管理员, Show_Name=超级管理员, Remark=null, Type=1]]]] 
 * */

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