gjson应用
1.简单的处理list和map
Java代码
1.Gsongson=newGson();
2.ListtestList=newArrayList();
3.testList.add("first");
4.testList.add("second");
5.StringlistToJson=gson.toJson(testList);
6.System.out.println(listToJson);
7.//prints["first","second"]
8.
9.MaptestMap=newHashMap();
10.testMap.put("id","id.first");
11.testMap.put("name","name.second");
12.StringmapToJson=gson.toJson(testMap);
13.System.out.println(mapToJson);
14.//prints{"id":"id.first","name":"name.second"}
Gsongson=newGson();
ListtestList=newArrayList();
testList.add("first");
testList.add("second");
StringlistToJson=gson.toJson(testList);
System.out.println(listToJson);
//prints["first","second"]
MaptestMap=newHashMap();
testMap.put("id","id.first");
testMap.put("name","name.second");
StringmapToJson=gson.toJson(testMap);
System.out.println(mapToJson);
//prints{"id":"id.first","name":"name.second"}
2.处理带泛型的集合
Java代码
1.List<TestBean>testBeanList=newArrayList<TestBean>();
2.TestBeantestBean=newTestBean();
3.testBean.setId("id");
4.testBean.setName("name");
5.testBeanList.add(testBean);
List<TestBean>testBeanList=newArrayList<TestBean>();
TestBeantestBean=newTestBean();
testBean.setId("id");
testBean.setName("name");
testBeanList.add(testBean);
Java代码
1.java.lang.reflect.Typetype=newcom.google.gson.reflect.TypeToken<List<T
estBean>>(){
2.}.getType();
3.StringbeanListToJson=gson.toJson(testBeanList,type);
4.System.out.println(beanListToJson);
5.//prints[{"id":"id","name":"name"}]
6.
7.List<TestBean>testBeanListFromJson=gson.fromJson(beanListToJson,type);
8.System.out.println(testBeanListFromJson);
9.//prints[TestBean@1ea5671[id=id,name=name,birthday=<null>]]
java.lang.reflect.Typetype=new
com.google.gson.reflect.TypeToken<List<TestBean>>(){
}.getType();
StringbeanListToJson=gson.toJson(testBeanList,type);
System.out.println(beanListToJson);
//prints[{"id":"id","name":"name"}]
List<TestBean>testBeanListFromJson=gson.fromJson(beanListToJson,type);
System.out.println(testBeanListFromJson);
//prints[TestBean@1ea5671[id=id,name=name,birthday=<null>]]
map等其他集合类型同上
3.Date类型转化
先写工具类
Java代码
1.importjava.lang.reflect.Type;
2.
3.importcom.google.gson.JsonDeserializationContext;
4.importcom.google.gson.JsonDeserializer;
5.importcom.google.gson.JsonElement;
6.importcom.google.gson.JsonParseException;
7.
8.publicclassUtilDateDeserializerimplementsJsonDeserializer<java.util.Da
te>{
9.
10.@Override
11.publicjava.util.Datedeserialize(JsonElementjson,TypetypeOfT,Jso
nDeserializationContextcontext)
12.throwsJsonParseException{
13.returnnewjava.util.Date(json.getAsJsonPrimitive().getAsLong());
14.}
15.}
importjava.lang.reflect.Type;
importcom.google.gson.JsonDeserializationContext;
importcom.google.gson.JsonDeserializer;
importcom.google.gson.JsonElement;
importcom.google.gson.JsonParseException;
publicclassUtilDateDeserializerimplementsJsonDeserializer<java.util.Date>{
@Override
publicjava.util.Datedeserialize(JsonElementjson,TypetypeOfT,
JsonDeserializationContextcontext)
throwsJsonParseException{
returnnewjava.util.Date(json.getAsJsonPrimitive().getAsLong());
}
}
Java代码
1.importjava.lang.reflect.Type;
2.
3.importcom.google.gson.JsonElement;
4.importcom.google.gson.JsonPrimitive;
5.importcom.google.gson.JsonSerializationContext;
6.importcom.google.gson.JsonSerializer;
7.
8.publicclassUtilDateSerializerimplementsJsonSerializer<java.util.Date>
{
9.
10.@Override
11.publicJsonElementserialize(java.util.Datesrc,TypetypeOfSrc,
12.JsonSerializationContextcontext){
13.returnnewJsonPrimitive(src.getTime());
14.}
15.
16.}
importjava.lang.reflect.Type;
importcom.google.gson.JsonElement;
importcom.google.gson.JsonPrimitive;
importcom.google.gson.JsonSerializationContext;
importcom.google.gson.JsonSerializer;
publicclassUtilDateSerializerimplementsJsonSerializer<java.util.Date>{
@Override
publicJsonElementserialize(java.util.Datesrc,TypetypeOfSrc,
JsonSerializationContextcontext){
returnnewJsonPrimitive(src.getTime());
}
}
Java代码
1./**
2.*序列化方法
3.*@parambean
4.*@paramtype
5.*@return
6.*/
7.publicstaticStringbean2json(Objectbean,Typetype){
8.Gsongson=newGsonBuilder().registerTypeAdapter(java.util.Date.c
lass,newUtilDateSerializer())
9..setDateFormat(DateFormat.LONG).create();
10.returngson.toJson(bean);
11.}
12.
13./**
14.*反序列化方法
15.*@paramjson
16.*@paramtype
17.*@return
18.*/
19.publicstatic<T>Tjson2bean(Stringjson,Typetype){
20.Gsongson=newGsonBuilder().registerTypeAdapter(java.util.Date.
class,newUtilDateDeserializer())
21..setDateFormat(DateFormat.LONG).create();
22.returngson.fromJson(json,type);
23.}
/**
*序列化方法
*@parambean
*@paramtype
*@return
*/
publicstaticStringbean2json(Objectbean,Typetype){
Gsongson=newGsonBuilder().registerTypeAdapter(java.util.Date.class,new
UtilDateSerializer())
.setDateFormat(DateFormat.LONG).create();
returngson.toJson(bean);
}
/**
*反序列化方法
*@paramjson
*@paramtype
*@return
*/
publicstatic<T>Tjson2bean(Stringjson,Typetype){
Gsongson=newGsonBuilder().registerTypeAdapter(java.util.Date.class,new
UtilDateDeserializer())
.setDateFormat(DateFormat.LONG).create();
returngson.fromJson(json,type);
}
现在开始测试
Java代码
1.List<TestBean>testBeanList=newArrayList<TestBean>();
2.TestBeantestBean=newTestBean();
3.testBean.setId("id");
4.testBean.setName("name");
5.testBean.setBirthday(newjava.util.Date());
6.testBeanList.add(testBean);
7.
8.java.lang.reflect.Typetype=newcom.google.gson.reflect.TypeToken<List<T
estBean>>(){
9.}.getType();
10.StringbeanListToJson=bean2json(testBeanList,type);
11.System.out.println("beanListToJson:"+beanListToJson);
12.//prints[{"id":"id","name":"name","birthday":1256531559390}]
13.
14.List<TestBean>testBeanListFromJson=json2bean(beanListToJson,type);
15.System.out.println(testBeanListFromJson);
16.//prints[TestBean@77a7f9[id=id,name=name,birthday=MonOct2612:39:05CS
T2009]]
List<TestBean>testBeanList=newArrayList<TestBean>();
TestBeantestBean=newTestBean();
testBean.setId("id");
testBean.setName("name");
testBean.setBirthday(newjava.util.Date());
testBeanList.add(testBean);
java.lang.reflect.Typetype=new
com.google.gson.reflect.TypeToken<List<TestBean>>(){
}.getType();
StringbeanListToJson=bean2json(testBeanList,type);
System.out.println("beanListToJson:"+beanListToJson);
//prints[{"id":"id","name":"name","birthday":1256531559390}]
List<TestBean>testBeanListFromJson=json2bean(beanListToJson,type);
System.out.println(testBeanListFromJson);
//prints[TestBean@77a7f9[id=id,name=name,birthday=MonOct2612:39:05CST2009]]
后记：对于java.sql.Date的转化同上类似，写两个类用于其序列化和反序列化即可
SQLDateDeserializerimplementsJsonDeserializer<java.sql.Date>
SQLDateSerializerimplementsJsonSerializer<java.sql.Date>
GsonBuilderapi:
com.google.gson
ClassGsonBuilder
java.lang.Object
com.google.gson.GsonBuilder
publicfinalclassGsonBuilderextendsObject
UsethisbuildertoconstructaGsoninstancewhenyouneedtosetconfiguration
optionsotherthanthedefault.ForGsonwithdefaultconfiguration,itis
simplertousenewGson().GsonBuilderisbestusedbycreatingit,andthen
invokingitsvariousconfigurationmethods,andfinallycallingcreate.
ThefollowingisanexampleshowshowtousetheGsonBuildertoconstructaGson
instance:
Gsongson=newGsonBuilder()
.registerTypeAdapter(Id.class,newIdTypeAdapter())
.serializeNulls()
.setDateFormat(DateFormat.LONG)
.setFieldNamingPolicy(FieldNamingPolicy.UPPER_CAMEL_CASE)
.setPrettyPrinting()
.setVersion(1.0)
.create();
NOTE:theorderofinvocationofconfigurationmethodsdoesnotmatter.
Author:
InderjeetSingh,JoelLeitch
ConstructorSummary
GsonBuilder()
CreatesaGsonBuilderinstancethatcanbeusedtobuildGsonwith
variousconfigurationsettings.
MethodSummary
Gsoncreate()
CreatesaGsoninstancebasedonthecurrent
configuration.
GsonBuilderexcludeFieldsWithModifiers(int...modifiers)
ConfiguresGsontoexcludesallclassfieldsthathave
thespecifiedmodifiers.
GsonBuilderexcludeFieldsWithoutExposeAnnotation()
ConfiguresGsontoexcludeallfieldsfromconsideration
forserializationordeserializationthatdonothavetheExpose
annotation.
GsonBuilderregisterTypeAdapter(Typetype,ObjecttypeAdapter)
ConfiguresGsonforcustomserializationor
deserialization.
GsonBuilderserializeNulls()
ConfigureGsontoserializenullfields.
GsonBuildersetDateFormat(intstyle)
ConfiguresGsontotoserializeDateobjectsaccording
tothestylevalueprovided.
GsonBuildersetDateFormat(intdateStyle,inttimeStyle)
ConfiguresGsontotoserializeDateobjectsaccording
tothestylevalueprovided.
GsonBuildersetDateFormat(Stringpattern)
ConfiguresGsontoserializeDateobjectsaccordingto
thepatternprovided.
GsonBuildersetFieldNamingPolicy(FieldNamingPolicynamingConvention)
ConfiguresGsontoapplyaspecificnamingpolicytoan
object'sfieldduringserializationanddeserialization.
GsonBuildersetPrettyPrinting()
ConfiguresGsontooutputJsonthatfitsinapagefor
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SUMMARY========
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SUMMARY===========
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prettyprinting.
GsonBuildersetVersion(doubleignoreVersionsAfter)
ConfiguresGsontoenableversioningsupport.
Methodsinheritedfromclassjava.lang.Object
equals,getClass,hashCode,notify,notifyAll,toString,wait,wait,wait
ConstructorDetail
GsonBuilder
publicGsonBuilder()
CreatesaGsonBuilderinstancethatcanbeusedtobuildGsonwithvarious
configurationsettings.GsonBuilderfollowsthebuilderpattern,anditis
typicallyusedbyfirstinvokingvariousconfigurationmethodstoset
desiredoptions,andfinallycallingcreate().
MethodDetail
setVersion
publicGsonBuildersetVersion(doubleignoreVersionsAfter)
ConfiguresGsontoenableversioningsupport.
Parameters:
ignoreVersionsAfter-anyfieldortypemarkedwithaversionhigher
thanthisvalueareignoredduringserializationordeserialization.
Returns:
areferencetothisGsonBuilderobjecttofulfillthe"Builder"
pattern
excludeFieldsWithModifiers
publicGsonBuilderexcludeFieldsWithModifiers(int...modifiers)
ConfiguresGsontoexcludesallclassfieldsthathavethespecified
modifiers.Bydefault,Gsonwillexcludeallfieldsmarkedtransientor
static.Thismethodwilloverridethatbehavior.
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DETAIL========
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DETAIL==========
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Parameters:
modifiers-thefieldmodifiers.Youmustusethemodifiersspecified
intheModifierclass.Forexample,Modifier.TRANSIENT,
Modifier.STATIC.
Returns:
areferencetothisGsonBuilderobjecttofulfillthe"Builder"
pattern
excludeFieldsWithoutExposeAnnotation
publicGsonBuilderexcludeFieldsWithoutExposeAnnotation()
ConfiguresGsontoexcludeallfieldsfromconsiderationforserialization
ordeserializationthatdonothavetheExposeannotation.
Returns:
areferencetothisGsonBuilderobjecttofulfillthe"Builder"
pattern
serializeNulls
publicGsonBuilderserializeNulls()
ConfigureGsontoserializenullfields.Bydefault,Gsonomitsallfields
thatarenullduringserialization.
Returns:
areferencetothisGsonBuilderobjecttofulfillthe"Builder"
pattern
Since:
1.2
setFieldNamingPolicy
publicGsonBuildersetFieldNamingPolicy(FieldNamingPolicynamingConvention)
ConfiguresGsontoapplyaspecificnamingpolicytoanobject'sfield
duringserializationanddeserialization.
Parameters:
namingConvention-theJSONfieldnamingconventiontousefor
serializationanddeserialization.
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Returns:
areferencetothisGsonBuilderobjecttofulfillthe"Builder"
pattern
setPrettyPrinting
publicGsonBuildersetPrettyPrinting()
ConfiguresGsontooutputJsonthatfitsinapageforprettyprinting.
ThisoptiononlyaffectsJsonserialization.
Returns:
areferencetothisGsonBuilderobjecttofulfillthe"Builder"
pattern
setDateFormat
publicGsonBuildersetDateFormat(Stringpattern)
ConfiguresGsontoserializeDateobjectsaccordingtothepatternprovided.
YoucancallthismethodorsetDateFormat(int)multipletimes,butonlythe
lastinvocationwillbeusedtodecidetheserializationformat.
Notethatthispatternmustabidebytheconventionprovidedby
SimpleDateFormatclass.SeethedocumentationinSimpleDateFormatformore
informationonvaliddateandtimepatterns.
Parameters:
pattern-thepatternthatdateswillbeserialized/deserialized
to/from
Returns:
areferencetothisGsonBuilderobjecttofulfillthe"Builder"
pattern
Since:
1.2
setDateFormat
publicGsonBuildersetDateFormat(intstyle)
ConfiguresGsontotoserializeDateobjectsaccordingtothestylevalue
provided.YoucancallthismethodorsetDateFormat(String)multipletimes,
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butonlythelastinvocationwillbeusedtodecidetheserialization
format.
Notethatthisstylevalueshouldbeoneofthepredefinedconstantsinthe
DateFormatclass.SeethedocumentationinDateFormatformoreinformation
onthevalidstyleconstants.
Parameters:
style-thepredefineddatestylethatdateobjectswillbe
serialized/deserializedto/from
Returns:
areferencetothisGsonBuilderobjecttofulfillthe"Builder"
pattern
Since:
1.2
setDateFormat
publicGsonBuildersetDateFormat(intdateStyle,
inttimeStyle)
ConfiguresGsontotoserializeDateobjectsaccordingtothestylevalue
provided.YoucancallthismethodorsetDateFormat(String)multipletimes,
butonlythelastinvocationwillbeusedtodecidetheserialization
format.
Notethatthisstylevalueshouldbeoneofthepredefinedconstantsinthe
DateFormatclass.SeethedocumentationinDateFormatformoreinformation
onthevalidstyleconstants.
Parameters:
dateStyle-thepredefineddatestylethatdateobjectswillbe
serialized/deserializedto/from
timeStyle-thepredefinedstyleforthetimeportionofthedate
objects
Returns:
areferencetothisGsonBuilderobjecttofulfillthe"Builder"
pattern
Since:
1.2
registerTypeAdapter
publicGsonBuilderregisterTypeAdapter(Typetype,
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ObjecttypeAdapter)
ConfiguresGsonforcustomserializationordeserialization.Thismethod
combinestheregistrationofanInstanceCreator,JsonSerializer,anda
JsonDeserializer.ItisbestusedwhenasingleobjecttypeAdapter
implementsalltherequiredinterfacesforcustomserializationwithGson.
Ifaninstancecreator,serializerordeserializerwaspreviously
registeredforthespecifiedtype,itisoverwritten.
Parameters:
type-thetypedefinitionforthetypeadapterbeingregistered
typeAdapter-Thisobjectmustimplementatleastoneofthe
InstanceCreator,JsonSerializer,andaJsonDeserializerinterfaces.
Returns:
areferencetothisGsonBuilderobjecttofulfillthe"Builder"
pattern
create
publicGsoncreate()
CreatesaGsoninstancebasedonthecurrentconfiguration.Thismethodis
freeofside-effectstothisGsonBuilderinstanceandhencecanbecalled
multipletimes.
Returns:
aninstanceofGsonconfiguredwiththeoptionscurrentlysetinthis
builder
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