Java的Jackson库中复杂对象集合的几种简单转换

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]]]]  * */