Java 如何从JSON中正确读取这些泛型？
我对我的第一个泛型容器相当有信心，但仍停留在如何在客户端对铸造进行描述上。这就是我参与学习Java 如何从JSON中正确读取这些泛型？,java,json,generics,libgdx,Java,Json,Generics,Libgdx,我对我的第一个泛型容器相当有信心，但仍停留在如何在客户端对铸造进行描述上。这就是我参与学习之前的工作： CommonNounContainer typeContainer = new Json().fromJson(CommonNounContainer.class, result); 我在考虑为每个类创建不同的容器，但这似乎不是一个好的设计。以下是我在新的泛型容器中进行的更新的非工作读取尝试： JSONContainer<CommonNoun> typeContainer = n
CommonNounContainer typeContainer = new Json().fromJson(CommonNounContainer.class, result);
JSONContainer<CommonNoun> typeContainer = new Json().fromJson(JSONContainer.class, result);
类型参数：
参数：
如果类型未知，则类型可能为null。
json
返回：
可能为空。
import java.util.ArrayList;
public class CommonNounContainer {
private CommonNoun myCommonNoun;
private ArrayList<CommonNounContainer> children;
public CommonNounContainer(CommonNoun concept) {
myCommonNoun = concept;
children = new ArrayList<CommonNounContainer>();
}
//Creates an empty shell. This would be for categories you want to group by, but not display/select in the select box.
public CommonNounContainer() {
children = new ArrayList<CommonNounContainer>();
}
public void addChildren(ArrayList<CommonNounContainer> newChildren) {
children.addAll(newChildren);
}
public void addChild(CommonNoun concept) {
children.add(new CommonNounContainer(concept));
}
public ArrayList<CommonNounContainer> getChildren() {
return children;
}
public CommonNoun getValue() {
return myCommonNoun;
}
public boolean hasChildren() {
if (children.size() > 0) return true;
else return false;
}
public String toString() {
return myCommonNoun.toString();
}
}
public class JSONContainer<T> {
private T myObject;
private ArrayList<JSONContainer<T>> children;
// public Class<T> typeParameterClass;
public JSONContainer() {
}
public JSONContainer(T anObject) {
myObject = anObject;
children = new ArrayList<JSONContainer<T>>();
}
/* public JSONContainer(T anObject, Class<T> typeParameterClass) {
myObject = anObject;
children = new ArrayList<JSONContainer<T>>();
this.typeParameterClass = typeParameterClass;
}
*/
public void addChildren(ArrayList<JSONContainer<T>> newChildren) {
children.addAll(newChildren);
}
public void addChild(T concept) {
children.add(new JSONContainer<T>(concept));
}
public ArrayList<JSONContainer<T>> getChildren() {
return children;
}
public T getValue() {
return myObject;
}
public boolean hasChildren() {
if (children.size() > 0) return true;
else return false;
}
public String toString() {
return myObject.toString();
}
}
import java.util.ArrayList；
公共类公共容器{
私有普通名词；
私人ArrayList儿童；
公共CommonNon容器（CommonNon概念）{
名词=概念；
children=newarraylist（）；
}
//创建一个空壳。这将用于您要按其分组的类别，但不用于在“选择”框中显示/选择。
公共容器（）{
children=newarraylist（）；
}
public void addChildren（ArrayList newChildren）{
children.addAll（newChildren）；
}
public void addChild（CommonNoun概念）{
添加（新容器（概念））；
}
公共ArrayList getChildren（）{
返回儿童；
}
公共CommonNoun getValue（）{
返回名词；
}
公共布尔hasChildren（）{
if（children.size（）>0）返回true；
否则返回false；
}
公共字符串toString（）{
返回myCommonNoun.toString（）；
}
}
公共类JSONContainer{
私有T对象；
私人ArrayList儿童；
//公共类typeParameterClass；
公共JSONContainer（）{
}
公共JSONContainer（T对象）{
myObject=一个对象；
children=newarraylist（）；
}
/*公共JSONContainer（T对象，类类型参数类）{
myObject=一个对象；
children=newarraylist（）；
this.typeParameterClass=typeParameterClass；
}
*/
public void addChildren（ArrayList newChildren）{
children.addAll（newChildren）；
}
公共儿童（T概念）{
添加（新JSONContainer（概念））；
}
公共ArrayList getChildren（）{
返回儿童；
}
公共T getValue（）{
返回myObject；
}
公共布尔hasChildren（）{
if（children.size（）>0）返回true；
否则返回false；
}
公共字符串toString（）{
返回myObject.toString（）；
}
}
public class CommonNoun extends Concept {
/**
*
*/
private static final long serialVersionUID = 6444629581712454049L;
public CommonNoun() {
super();
}
public CommonNoun(String name, ConceptID cidIn) {
super(name, cidIn);
this.form = ConceptDefs.COMMON_NOUN;
}
}
public class Concept implements Serializable {
/**
*
*/
private static final long serialVersionUID = 2561549161503772431L;
private ConceptID cid = null;
private final String name;
Integer form = 0;
// ArrayList<ProperRelationship> myRelationships = null;
/* @Deprecated
public Concept(String name) {
this.name = name;
}*/
public Concept() {
name = "";
}
public Concept(String name, ConceptID cidIn) {
// this(name);
this.name = name;
cid = cidIn;
}
/*
* This should be over-ridden by any subclasses
*/
public Integer getForm() {
return form;
}
public ConceptID getID() {
return cid;
}
public void setID(ConceptID cidIn) {
cid = cidIn;
}
//this doesn't make any sense. Throw exception?
public String getName() {
return name;
}
public boolean isCommon() {
return true;
}
/**
*
* @return
*/
@Override
public String toString() {
return getName() + "(" + cid.toString() + ")";
}
public boolean equals(Concept other) {
return ((getID().equals(other.getID())));
}
}
public class ConceptID implements Serializable {
long oid;
public ConceptID() {
oid = -1;
}
public ConceptID(long oid) {
this.oid = oid;
}
public long getValue() {
return oid;
}
/**
*
* @return
*/
@Override
public String toString() {
return Long.toString(oid);
}
public Long toLong() {
return Long.valueOf(oid);
}
public boolean equals(ConceptID other) {
return (oid == other.getValue());
}
/**
* Factory model for generating ConceptIDs
*
* This one is here as a convenience as many IDs come in as a String from web POSTs
* @param idAsString
* @return
*/
static public ConceptID parseIntoID(String idAsString) {
ConceptID returnID = null;
try {
returnID = new ConceptID( Long.parseLong(idAsString) );
} catch (Exception e) {
System.err.println("Expected the string, " + idAsString + ", to be Long parsable.");
e.printStackTrace();
}
return returnID;
}
public类CommonNoun扩展了概念{
/**
*
*/
私有静态最终长serialVersionUID=6444629581712454049L；
公共名词{
超级（）；
}
public CommonNoun（字符串名，ConceptID cidIn）{
super（名称，cidIn）；
this.form=ConceptDefs.COMMON_名词；
}
}
公共类概念实现了可序列化{
/**
*
*/
私有静态最终长serialVersionUID=2561549161503772431L；
私有概念ID cid=null；
私有最终字符串名；
整数形式=0；
//ArrayList myRelationships=null；
/*@弃用
公共概念（字符串名称）{
this.name=名称；
}*/
公共概念（）{
name=“”；
}
公共概念（字符串名称，概念ID cidIn）{
//这个(名字),；
this.name=名称；
cid=cidIn；
}
/*
*这应该被任何子类所超越
*/
公共整数getForm（）{
申报表；
}
公共概念ID getID（）{
返回cid；
}
public void setID（ConceptID cidIn）{
cid=cidIn；
}
//这没有任何意义。抛出异常？
公共字符串getName（）{
返回名称；
}
公共布尔值isCommon（）{
返回true；
}
/**
*
*@返回
*/
@凌驾
公共字符串toString（）{
返回getName（）+”（“+cid.toString（）+”）；
}
公共布尔等于（概念其他）{
return（（getID（）.equals）（other.getID（））；
}
}
公共类ConceptID实现了可序列化{
长圆形；
公共概念ID（）{
oid=-1；
}
公共概念ID（长oid）{
this.oid=oid；
}
公共长getValue（）{
返回oid；
}
/**
*
*@返回
*/
@凌驾
公共字符串toString（）{
返回Long.toString（oid）；
}
公营长龙（{
返回Long.valueOf（oid）；
}
公共布尔等于（概念ID其他）{
返回（oid==other.getValue（））；
}
/**
*用于生成概念ID的工厂模型
*
*这一个是为了方便，因为许多ID都是以字符串形式从web帖子中输入的
*@param-idAsString
*@返回
*/
静态公共概念ID parseIntoID（字符串idAsString）{
ConceptID returnID=null；
尝试
import java.util.ArrayList;
public class CommonNounContainer {
private CommonNoun myCommonNoun;
private ArrayList<CommonNounContainer> children;
public CommonNounContainer(CommonNoun concept) {
myCommonNoun = concept;
children = new ArrayList<CommonNounContainer>();
}
//Creates an empty shell. This would be for categories you want to group by, but not display/select in the select box.
public CommonNounContainer() {
children = new ArrayList<CommonNounContainer>();
}
public void addChildren(ArrayList<CommonNounContainer> newChildren) {
children.addAll(newChildren);
}
public void addChild(CommonNoun concept) {
children.add(new CommonNounContainer(concept));
}
public ArrayList<CommonNounContainer> getChildren() {
return children;
}
public CommonNoun getValue() {
return myCommonNoun;
}
public boolean hasChildren() {
if (children.size() > 0) return true;
else return false;
}
public String toString() {
return myCommonNoun.toString();
}
}
public class JSONContainer<T> {
private T myObject;
private ArrayList<JSONContainer<T>> children;
// public Class<T> typeParameterClass;
public JSONContainer() {
}
public JSONContainer(T anObject) {
myObject = anObject;
children = new ArrayList<JSONContainer<T>>();
}
/* public JSONContainer(T anObject, Class<T> typeParameterClass) {
myObject = anObject;
children = new ArrayList<JSONContainer<T>>();
this.typeParameterClass = typeParameterClass;
}
*/
public void addChildren(ArrayList<JSONContainer<T>> newChildren) {
children.addAll(newChildren);
}
public void addChild(T concept) {
children.add(new JSONContainer<T>(concept));
}
public ArrayList<JSONContainer<T>> getChildren() {
return children;
}
public T getValue() {
return myObject;
}
public boolean hasChildren() {
if (children.size() > 0) return true;
else return false;
}
public String toString() {
return myObject.toString();
}
}
public class CommonNoun extends Concept {
/**
*
*/
private static final long serialVersionUID = 6444629581712454049L;
public CommonNoun() {
super();
}
public CommonNoun(String name, ConceptID cidIn) {
super(name, cidIn);
this.form = ConceptDefs.COMMON_NOUN;
}
}
public class Concept implements Serializable {
/**
*
*/
private static final long serialVersionUID = 2561549161503772431L;
private ConceptID cid = null;
private final String name;
Integer form = 0;
// ArrayList<ProperRelationship> myRelationships = null;
/* @Deprecated
public Concept(String name) {
this.name = name;
}*/
public Concept() {
name = "";
}
public Concept(String name, ConceptID cidIn) {
// this(name);
this.name = name;
cid = cidIn;
}
/*
* This should be over-ridden by any subclasses
*/
public Integer getForm() {
return form;
}
public ConceptID getID() {
return cid;
}
public void setID(ConceptID cidIn) {
cid = cidIn;
}
//this doesn't make any sense. Throw exception?
public String getName() {
return name;
}
public boolean isCommon() {
return true;
}
/**
*
* @return
*/
@Override
public String toString() {
return getName() + "(" + cid.toString() + ")";
}
public boolean equals(Concept other) {
return ((getID().equals(other.getID())));
}
}
public class ConceptID implements Serializable {
long oid;
public ConceptID() {
oid = -1;
}
public ConceptID(long oid) {
this.oid = oid;
}
public long getValue() {
return oid;
}
/**
*
* @return
*/
@Override
public String toString() {
return Long.toString(oid);
}
public Long toLong() {
return Long.valueOf(oid);
}
public boolean equals(ConceptID other) {
return (oid == other.getValue());
}
/**
* Factory model for generating ConceptIDs
*
* This one is here as a convenience as many IDs come in as a String from web POSTs
* @param idAsString
* @return
*/
static public ConceptID parseIntoID(String idAsString) {
ConceptID returnID = null;
try {
returnID = new ConceptID( Long.parseLong(idAsString) );
} catch (Exception e) {
System.err.println("Expected the string, " + idAsString + ", to be Long parsable.");
e.printStackTrace();
}
return returnID;
}
Type safety: The expression of type JSONContainer needs unchecked conversion to conform to JSONContainer
...Communicator.java uses unchecked or unsafe operations.
...Recompile with -Xlint:unchecked for details.
result = {"myObject":{"cid":{"oid":129},"name":"technology","form":1},"children":[]}
com.badlogic.gdx.utils.SerializationException: Field not found: cid (java.lang.Object)...
...
private static final String JADEN_AS_JSON = "{jden:{class:CommonNoun,person:Jaden,place:Hollywood,thing:HashBeen}}";
private static final String JADEN_FAILS_AS_ACTOR = "{jden:{class:CommonNoun,person:Jaden,place:Hollywood,thing:HasBeen, cid:{oid:129} }}";
static public void main( String ... args ){
out.printf( "%1$22s%n", "foo");
JSONContainer< CommonNoun > wtf = new JSONContainer< > ( );
CommonNoun wtBrattyF = new CommonNoun( "Jaden Pinkett Smith", "Hollywood", "HasBeen" );
wtf.setJden( wtBrattyF );
out.printf( "%1$42s%n", wtf );
Json jden = new Json();
out.printf("%1$59s%n", jden.toJson( wtf ) );
JSONContainer wtReifiableF = jden.fromJson(JSONContainer.class, JADEN_AS_JSON); /* This is fine */
out.printf("%1$59s%n", jden.toJson( wtReifiableF ) );
JSONContainer/*< CommonNoun >*/ wtUnReifiableF = jden.fromJson( JSONContainer.class, JADEN_AS_JSON );
wtUnReifiableF = jden.fromJson( JSONContainer.class, JADEN_FAILS_AS_ACTOR ); /* This causes the error you reported */
}
...
JSONContainer [ jden: CommonNoun [ person: Jaden Pinkett Smith, place: Hollywood, thing: HasBeen ] ]
{jden:{class:CommonNoun,person:Jaden Pinkett Smith,place:Hollywood,thing:HasBeen}}
{jden:{class:CommonNoun,person:Jaden,place:Hollywood,thing:HashBeen}}
Exception in thread "main" com.badlogic.gdx.utils.SerializationException: Field not found: cid (CommonNoun)
Serialization trace:
{}.jden.cid
jden (JSONContainer)
at com.badlogic.gdx.utils.Json.readFields(Json.java:893)
at com.badlogic.gdx.utils.Json.readValue(Json.java:1074)
at com.badlogic.gdx.utils.Json.readFields(Json.java:902)
at com.badlogic.gdx.utils.Json.readValue(Json.java:1074)
at com.badlogic.gdx.utils.Json.fromJson(Json.java:829)
at DeduperAnswer.main(DeduperAnswer.java:33)
public class Cid {
int oid;
/* ... getter and setter elided ... */
}
public class CommonNoun {
Cid cid;
String name;
int form;
/* ... getters and setters elided ... */
}
result = {"myObject":{"cid":{"oid":129},"name":"technology","form":1},"children":[]}
{myObject:{class:CommonNoun,cid:{oid:139},name:Jada Pinkett Smith,form:69},children:[{myObject:{class:CommonNoun,cid:{oid:666},name:Jaden Pinkett Smith,form:-666},children:[]},{myObject:{class:CommonNoun,cid:{oid:69},name:Willow Pinkett Smith,form:69},children:[]}]}