在Android中發送和接收json obj

Question

我目前正在使用一個可以訪問在線游戲以獲取我的帳戶信息的應用程序。 我需要使用JSON與服務器通信。 我使用以下代碼嘗試與服務器通信，但沒有來自服務器的響應。 我也注意到httpclient和其他一些流行的類已被棄用，我找不到一些適當的教程來教我這個主題。 任何幫助表示贊賞。

activity_main.xml中

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="deardanielxd.travain2.MainActivity">

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:text="Username : "
    android:id="@+id/Username_Lbl"
    android:layout_alignParentTop="true"
    android:layout_alignParentStart="true"
    android:editable="true"
    android:minHeight="20dp"
    android:layout_alignBottom="@+id/Username_Field"
    android:layout_toStartOf="@+id/Username_Field"
    android:layout_alignEnd="@+id/Password_Lbl" />

<EditText
    android:layout_width="wrap_content"
    android:layout_height = "40dp"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:id="@+id/Username_Field"
    android:editable="true"
    android:contextClickable="true"
    android:textIsSelectable="true"
    android:enabled="true"
    android:focusable="true"
    android:clickable="true"
    android:inputType="text"
    android:minHeight="40dp"
    android:layout_alignParentTop="true"
    android:layout_alignEnd="@+id/Load_Btn"
    android:layout_toEndOf="@+id/Password_Lbl" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:text="Password : "
    android:id="@+id/Password_Lbl"
    android:layout_below="@+id/Username_Lbl"
    android:layout_alignParentStart="true"
    android:minHeight="20dp"
    android:layout_alignBottom="@+id/Password_Field" />

<EditText
    android:layout_width="wrap_content"
    android:layout_height="40dp"
    android:textAppearance="?android:attr/textAppearanceSmall"
    android:id="@+id/Password_Field"
    android:password="true"
    android:editable="true"
    android:textIsSelectable="true"
    android:enabled="true"
    android:focusable="true"
    android:contextClickable="true"
    android:clickable="true"
    android:inputType="text"
    android:minHeight="40dp"
    android:layout_below="@+id/Username_Field"
    android:layout_alignParentEnd="true"
    android:layout_alignStart="@+id/Username_Field" />

<Button
    style="?android:attr/buttonStyleSmall"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Load"
    android:id="@+id/Load_Btn"
    android:layout_alignParentEnd="true"
    android:layout_alignBottom="@+id/spinner"
    android:layout_below="@+id/Password_Field" />

<Spinner
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/spinner"
    android:spinnerMode="dropdown"
    android:layout_alignParentStart="true"
    android:layout_toStartOf="@+id/Load_Btn"
    android:layout_below="@+id/Password_Lbl" />

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/SysMsg"
    android:layout_alignParentStart="true"
    android:layout_alignParentBottom="true"
    android:layout_alignParentEnd="true"
    android:text="System : "
    android:textColor="#FF0000" />

<ScrollView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/scrollView"
    android:layout_below="@+id/spinner"
    android:layout_alignParentStart="true"
    android:layout_above="@+id/SysMsg"
    android:layout_alignParentEnd="true" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/OutPut"
        android:enabled="true" />
</ScrollView>

MainActivity.java

package deardanielxd.travain2;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import org.json.JSONObject;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;


public class MainActivity extends AppCompatActivity {

    Spinner spinner;
    EditText Username, Password;
    Button Load_Btn;
    TextView Main_Output;
    TextView Sys_Output;
    String server = "";
    boolean debug = true;
    PlayerInfo curr = new PlayerInfo();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        SetupGadget();
        attachListener();

    }

    private void SetupGadget() {
        spinner = (Spinner) findViewById(R.id.spinner);
        Username = (EditText) findViewById(R.id.Username_Field);
        Password = (EditText) findViewById(R.id.Password_Field);
        Load_Btn = (Button) findViewById(R.id.Load_Btn);
        Main_Output = (TextView) findViewById(R.id.OutPut);
        Sys_Output = (TextView) findViewById(R.id.SysMsg);

        ArrayAdapter adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,Constants.Servers);
        spinner.setAdapter(adapter);
    }

    private void attachListener() {
        Load_Btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (debug) {
                    MainOutput( "Username : " + Username.getText());
                    MainOutput( "Password : " + Password.getText());
                    MainOutput( "Server : " + server);
                    MainOutput( "Internet Connection : " + (InternetAccess()?"Yes":"No"));
                    MainOutput( "" );
                }

                new test(MainActivity.this).execute();

            }
        });

        spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                server = parent.getSelectedItem().toString();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });

    }

    private void SystemOutput(String output) {
        Sys_Output.setText("System : " + output);
    }

    public void MainOutput(String output) {
        Main_Output.append("\n" + output);
    }

    private boolean InternetAccess() {
        ConnectivityManager cm =
                (ConnectivityManager)this.getSystemService(Context.CONNECTIVITY_SERVICE);

        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
        return activeNetwork != null &&
                activeNetwork.isConnectedOrConnecting();

    }

    public class test extends AsyncTask<Void, Void, Void>

    {
        private MainActivity MA;

        test(MainActivity ma) {
            MA = ma;
        }

        @Override
        protected Void doInBackground(Void... n) {

            try {
                URL url = new URL("http://"+MA.server+"/api/external.php");
                HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();

                urlConnection.setDoOutput(true);
                urlConnection.setRequestProperty("Content-Type","application/json");
                urlConnection.setRequestProperty("Host", "android.schoolportal.gr");
                urlConnection.setRequestMethod("POST");
                urlConnection.setUseCaches(false);
                urlConnection.connect();

                OutputStream printout = new DataOutputStream(urlConnection.getOutputStream ());
                printout.write(URLEncoder.encode(this.getObj().toString(),"UTF-8").getBytes());
                printout.flush ();
                printout.close ();

                try {
                    urlConnection.setRequestMethod("GET");
                    urlConnection.setDoInput(true);
                    InputStream in = new BufferedInputStream(urlConnection.getInputStream());
                    BufferedReader r = new BufferedReader(new InputStreamReader(in));
                    StringBuilder total = new StringBuilder(in.available());
                    String line;
                    while ((line = r.readLine()) != null) {
                        total.append(line).append('\n');
                    }
                    MA.MainOutput(total.toString());
                    MA.MainOutput("End of Doc");
                } finally {
                    urlConnection.disconnect();
                    return null;
                }
            } catch (java.net.MalformedURLException e) {

            } catch (java.io.IOException e) {

            };
            return null;

        }

        private JSONObject getObj() {

            JSONObject jobj = new JSONObject();
            try {
                jobj.put("email","funckybuggy@gmail.com");
                jobj.put("siteName","EasyTravian");
                jobj.put("sitUrl","testing.com");
                jobj.put("public",false);
            } catch (org.json.JSONException e) {

            }
            return jobj;

        }

    }

    public PlayerInfo getCurrentPlayerInfo() {
        return this.curr;
    }

    public void UpdateCurr() {
        this.curr.Username = this.Username.getText().toString();
        this.curr.Password = this.Password.getText().toString();
        this.curr.Server = this.server;
    }

    }

Constants.java

public class Constants {
public static final String[] Servers = {
    "ts1.travian.hk",
    "ts2.travian.hk",
    "ts20.travian.hk",
    "tx3.travian.hk",
    "ts4.travian.hk",
    "ts19.travian.hk",
    "ts3.travian.hk",
    "ts6.travian.hk",
    "ts5.travian.hk"
};

}

Answer 1

你應該使用Volley Library。 這對Rest API來說非常好。

管理服務器調用很簡單。

通過編譯添加庫

compile 'com.android.volley:volley:1.0.0'

然后創建一個Singleton類來處理所有的截擊請求。

Volley提供了JsonArrayRequest和JsonObjectRequest，它們在網絡調用期間非常有用。

這是凌空單身人士班

public class MyApplication extends Application
{

    private RequestQueue mRequestQueue;
    private static MyApplication mInstance;

    @Override
    public void onCreate()
    {
        super.onCreate();
        mInstance = this;
    }

    public static synchronized MyApplication getInstance()
    {
        return mInstance;
    }

    public RequestQueue getReqQueue()
    {
        if (mRequestQueue == null)
        {
            mRequestQueue = Volley.newRequestQueue(getApplicationContext());
        }

        return mRequestQueue;
    }

    public <T> void addToReqQueue(Request<T> req, String tag)
    {

        getReqQueue().add(req);
    }

    public <T> void addToReqQueue(Request<T> req)
    {

        getReqQueue().add(req);
    }

    public void cancelPendingReq(Object tag)
    {
        if (mRequestQueue != null) {
            mRequestQueue.cancelAll(tag);
        }
    }
}

將其添加到清單中的應用程序標記

<application
android:name="MyApplication">

這是一個示例JsonObjectRequest

JsonObjectRequest request = new JsonObjectRequest("requestMethod","url","input_data",
                        new Response.Listener<JSONObject>()
                        {
                            @Override
                            public void onResponse(JSONObject response)
                            {
                            }
                        },
                        new Response.ErrorListener()
                        {
                            @Override
                            public void onErrorResponse(VolleyError error)
                            {
                            }
                        });
                MyApplication.getInstance().addToReqQueue(request);

Answer 2

我不認為你應該編碼消息的正文。 它被稱為“URLEncoder”的原因是因為它用於編碼URL，但這是您的消息正文。

此外，您擁有的內部try塊是多余的，您還應該在請求中間將請求方法更改為GET。

沒有必要刷新字節。

請記住，對於POST請求，在您使用InputStream讀取響應之前不會發送任何內容。