Question

所以我得到了这个JSON：

{ "games": [
{
  "location": "germany",
  "team1": {
    "name": "test1",
    "tore": "2"
  },
  "team2": {
    "name": "test2",
    "tore": "3"
  }
},...

我的这个JSON的模型类看起来像那样（我认为我得到了错误）

MODEL CLASS：

import com.google.gson.annotations.SerializedName;

public class GameModel {

    public String location;
    @SerializedName("team1")
    public Team team1;
    @SerializedName("team2")
    public Team team2;


    public String getLocation() {
        return zeitpunkt;
    }

    public void setLocation(String location) {
        this.location= location;
    }

class Team
    public String name;
    public String tore;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getTore() {
        return tore;
    }

    public void setTore(String tore) {
        this.tore = tore;
    }

    @Override
    public String toString() {
        return "Team{" +
                name='" + name + '\'' +
                ", tore='" + tore + '\'' +
                '}';
    }
}

我的GSON看起来就像那样..

GSON课程

JSONObject parentObject = new JSONObject(finalJson);
JSONArray parentArray = parentObject.getJSONArray("games");

gameModelList = new ArrayList<>();

Gson gson2 = new Gson();
for(int i=0; i<parentArray.length(); i++) {
    JSONObject finalObject = parentArray.getJSONObject(i);
    GameModel inputGame = gson2.fromJson(finalObject.toString(), GameModel.class);    
    gameModelList.add(inputGame);
}
return gameModelList.toString();

games的位置可以在我的CustomAdapter类中调用，但每次我都希望获得team1的名称

GameModel gm = getItem(position);
tvTeamOne.setText("" +gm.team1.getName());

我得到java.null.lang pointer exception 我也尝试了调试器，它显示了team1:null，所以他没有得到String

logcat的：

07-04 13:26:53.720 25600-25600/de.xxxxxxx.app.mc.xxxxxx E/AndroidRuntime: FATAL EXCEPTION: main
    java.lang.NullPointerException
    at de.xxxxx.app.mc.xxxxx.GameAdapter.getView(GameAdapter.java:40)
    at android.widget.AbsListView.obtainView(AbsListView.java)
    at android.widget.ListView.measureHeightOfChildren(ListView.java)
    at android.widget.ListView.onMeasure(ListView.java)
    at android.view.View.measure(View.java)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java)
    at android.view.View.measure(View.java)
    at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java)
    at android.widget.RelativeLayout.onMeasure(RelativeLayout.java)
    at android.view.View.measure(View.java)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java)
    at android.view.View.measure(View.java)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java)
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java)
    at android.widget.LinearLayout.measureVertical(LinearLayout.java)
    at android.widget.LinearLayout.onMeasure(LinearLayout.java)
    at android.view.View.measure(View.java)
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java)
    at android.widget.FrameLayout.onMeasure(FrameLayout.java)
    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java)
    at android.view.View.measure(View.java)
    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java)
    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java)
    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java)
    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java)
    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java)
    at android.view.Choreographer$CallbackRecord.run(Choreographer.java)
    at android.view.Choreographer.doCallbacks(Choreographer.java)
    at android.view.Choreographer.doFrame(Choreographer.java)
    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java)
    at android.os.Handler.handleCallback(Handler.java)
    at android.os.Handler.dispatchMessage(Handler.java)
    at android.os.Looper.loop(Looper.java)
    at android.app.ActivityThread.main(ActivityThread.java)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java)
    at dalvik.system.NativeStart.main(Native Method)

Answer 1

首先创建模型：

public class Team1
{
    public String name;
    public String tore;
}

public class Team2
{
    public String name;
    public String tore;
}

public class Game
{
    public String location;
    public Team1 team1;
    public Team2 team2;
}

public class YourRootObject
{
    public List<Game> games;
}

然后简单解析到对象：

Gson gson = new Gson();
try {
    YourRootObject result = (YourRootObject) gson.fromJson(yourJson, YourRootObject.class);
catch(Exception e){}

并且在结果中所有数据（如果存在）将被正确解析并且您将在值

中获得空值

Answer 2

这里的所有代码都是无关紧要的。只有“GameAdapter”getview是必需的。我认为既然你在调用“getItem（position）”

您需要像这样更改此方法。

class A {

int i = 10;

public void printValue() {

System.out.println("Value-A");

}

}
class B extends A{

 int i = 12;

public void printValue() {

System.out.print("Value-B" + i);

}

}

public class Test{

public static void main(String argv[]){

 A a = new B();

 a.printValue();

System.out.println("===>"+a.i); // This line print 10 instead of 12 

}

}

希望这有帮助。

使用GSON创建复杂的JSON模型

2 个答案: