Java的Jackson库中复杂对象集合的几种简单转换

packagecom;

importjava.io.BufferedReader;

importjava.io.ByteArrayInputStream;

importjava.io.IOException;

importjava.io.InputStreamReader;

importjava.util.List;

importcom.fasterxml.jackson.core.JsonParseException;

importcom.fasterxml.jackson.databind.JavaType;

importcom.fasterxml.jackson.databind.JsonMappingException;

importcom.fasterxml.jackson.databind.ObjectMapper;

/**

 * jackson 复杂 对象集合 的几种简单转换

 * @author lenovo

 *

 * @param

 */

publicclassMain

{

 staticObjectMapper mapper =newObjectMapper();

 publicstaticvoidmain(String[] args)throwsJsonParseException,

   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().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);

  Listme = 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().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);

  Listlist = 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

  */

 publicT jsonStreamConverObject(String josn, Classclz)

 {

  T t =null;

  // ObjectMapper jacksonMapper = new ObjectMapper();

  InputStreamReader in =newInputStreamReader(newByteArrayInputStream(

    josn.getBytes()));

  BufferedReader streamReader =newBufferedReader(in);

  StringBuilder buff =newStringBuilder();

  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();

  }

  returnt;

 }

 /***

  * 转对象

  * @param josn

  * @param clz

  * @return

  */

 publicT jsonConverObject(String josn, Classclz)

 {

  T t =null;

  try

  {

   t = mapper.readValue(josn, clz);

  }catch(JsonParseException e)

  {

   e.printStackTrace();

  }catch(JsonMappingException e)

  {

   e.printStackTrace();

  }catch(IOException e)

  {

   e.printStackTrace();

  }

  returnt;

 }

 /**

  * 转集合

  * @param josn

  * @param clz

  * @return

  */

 publicListjsonConverList(String josn, Classclz)

 {

  Listme =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();

  }

  returnme;

 }

}

/**

 * 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]]]]

 * */