Android利用Gson实现对象和Json数据的相互转换
MainActitity如下:
packagecc.test;
importandroid.app.Activity;
importandroid.os.Bundle;
/
Demo描述:
利用Gson实现对象和Json数据的相互转换
Demo描述:
通过一个网络请求,获取JSON数据
注意:
1网络请求的参数是JSON格式的数据
2请求结果返回的亦是JSON格式的数据
/
publicclassMainActivityextendsActivity{
@Override
publicvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
init();
}
privatevoidinit(){
newThread(){
publicvoidrun(){
GetJsonDataByPosthttpJsonPost=newGetJsonDataByPost();
String[]pathArray=httpJsonPost.getPathArray("dev0003");
for(inti=0;i
System.out.println(pathArray[i]);
}
}
}.start();
}
}
GetJsonDataByPost如下:
packagecc.test;
importjava.io.BufferedReader;
importjava.io.IOException;
importjava.io.InputStream;
importjava.io.InputStreamReader;
importjava.io.UnsupportedEncodingException;
importorg.apache.http.HttpResponse;
importorg.apache.http.client.ClientProtocolException;
importorg.apache.http.client.methods.HttpPost;
importorg.apache.http.entity.StringEntity;
importorg.apache.http.impl.client.DefaultHttpClient;
importorg.apache.http.params.HttpConnectionParams;
importorg.apache.http.protocol.HTTP;
publicclassGetJsonDataByPost{
staticprivateStringService_URL="Yoururl";
staticprivateintTIMEOUT=1201000;
StringmMethodName;
publicString[]getPathArray(Stringdevnum){
try{
mMethodName="GetPicByUser";
String[]pathArray=null;
//将调用API的参数封装成JSON格式
StringjsonParams=JsonUtils.getJsonRequestParams(devnum);
//返回的JSON数据
StringjsonResult=getJsonDataByPost(jsonParams);
//从返回的JSON数据获取其包含的一个数组
pathArray=JsonUtils.getJsonRequestResponse(jsonResult);
returnpathArray;
}catch(Exceptione){
e.printStackTrace();
}
returnnull;
}
publicStringgetJsonDataByPost(Stringjson){
Stringresult=null;
try{
StringEntityentity=newStringEntity(json,HTTP.UTF_8);
entity.setContentType("application/json");
DefaultHttpClientclient=newDefaultHttpClient();
client.getParams().setIntParameter(HttpConnectionParams.SO_TIMEOUT,TIMEOUT);
client.getParams().setIntParameter(HttpConnectionParams.CONNECTION_TIMEOUT,TIMEOUT);
if(mMethodName==null){
returnnull;
}
HttpPosthttpPost=newHttpPost(Service_URL+mMethodName);
httpPost.setEntity(entity);
HttpResponseresponse=client.execute(httpPost);
InputStreaminputStream=response.getEntity().getContent();
StringBufferbuffer=newStringwww.wang027.comBuffer();
InputStreamReaderinputReader=newInputStreamReader(inputStream);
BufferedReaderbufferReader=newBufferedReader(inputReader);
Stringstr=newString("");
while((str=bufferReader.readLine())!=null){
buffer.append(str);
}
bufferReader.close();
result=buffer.toString();
System.out.println("--->API的请求结果result="+result);
}catch(UnsupportedEncodingExceptione){
e.printStackTrace();
}catch(ClientProtocolExceptione){
e.printStackTrace();
}catch(IOExceptione){
e.printStackTrace();
}
returnresult;
}
}
JsonUtils如下:
packagecc.test;
importcom.google.gson.Gson;
importcom.google.gson.JsonSyntaxException;
publicclassJsonUtils{
//该对象用于封装请求API的参数.
//请求时会将该对象转换为JSON格式的数据
staticclassJsonRequestParams{
Stringdevsn;
intuploadid;
floathealthScore;
}
//该对象用于封装请求API返回后的结果.
//即会将JSON格式的数据结果封装成该对象
staticclassJsonRequestResult{
Stringresultcode;
intuploadid;
String[]pics;
floatbeat;
Stringcrtime;
}
//将请求的参数封装成JSON的格式
publicstaticStringgetJsonRequestParams(Stringdevnum){
try{
JsonRequestParamsjsonRequestParams=newJsonRequestParams();
jsonRequestParams.devsn=devnum;
jsonRequestParams.uploadid=0;
jsonRequestParams.healthScore=0.0f;
Gsongson=newGson();
//将对象转换为JSON数据
StringjsonRequestParamsString=gson.toJson(jsonRequestParams);
System.out.println("--->封装后的API请求参数jsonRequestParamsString="+jsonRequestParamsString);
returnjsonRequestParamsString;
}catch(Exceptione){
e.printStackTrace();
}
returnnull;
}
publicstaticString[]getJsonRequestResponse(Stringret){
try{
Gsongson=newGson();
//将返回的JSON数据转换为对象JsonRequestResult
JsonRequestResultmJsonGetPicResponse=gson.fromJson(ret,JsonRequestResult.class);
if(mJsonGetPicResponse.resultcode.contains("ok")){
//从对象中获取除pics外的各个字段且输出显示
System.out.println("--->mJsonGetPicResponse.resultcode="+mJsonGetPicResponse.resultcode);
System.out.println("--->mJsonGetPicResponse.beat="+mJsonGetPicResponse.beat);
System.out.www.baiyuewang.netprintln("--->mJsonGetPicResponse.uploadid="+mJsonGetPicResponse.uploadid);
System.out.println("--->mJsonGetPicResponse.crtime="+mJsonGetPicResponse.crtime);
//从对象中获取pics字段,且返回
returnmJsonGetPicResponse.pics;
}
}catch(JsonSyntaxExceptione){
e.printStackTrace();
}
returnnull;
}
}
main.xml如下:
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#ffffff">
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="HelloEveryone"
android:layout_centerInParent="true"/>
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