Java的Jackson库中复杂对象集合的几种简单转换

话不多说，请看代码：

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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