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「Android/HttpRequest通信/HttpURLConnection」の版間の差分

提供: 初心者エンジニアの簡易メモ
移動: 案内、 検索
(→‎uaを設定しない場合とwebviewからもてっくる場合)
(→‎Causee: java.security.cert.CertificateException: Chain validation failedエラーが出るとき)
 
(同じ利用者による、間の26版が非表示)
行5: 行5:
 
==サンプル==
 
==サンプル==
 
同期処理のみ(AsyncTaskなどで実行すること)
 
同期処理のみ(AsyncTaskなどで実行すること)
−
import java.io.BufferedReader;
+
 
−
import java.io.IOException;
+
get
−
import java.io.InputStream;
+
<pre>
−
import java.io.InputStreamReader;
+
CustomHttpURLConnection http = new CustomHttpURLConnection();
−
import java.net.HttpURLConnection;
+
HashMap<String, String> params = new HashMap<String, String>();
−
import java.net.SocketTimeoutException;
+
params.put("errorlog", stackTrace);
−
import java.net.URL;
+
http.setParams(params);
−
  String strGetUrl = "https://api.github.com/feeds";
+
http.execGet("https://api.github.com/feeds");
−
  // System.setProperty("http.agent", "Dalvik/2.1.0 (Linux; U; Android 9; H8216 Build/PDP-PKQ1.180708.001-10229)"); // System.getProperty("http.agent");
+
</pre>
−
  Log.i("HttpURLConnection", "ua=" + System.getProperty("http.agent"));
+
post
−
  HttpURLConnection urlConn = null;
+
<pre>
−
  InputStream in = null;
+
CustomHttpURLConnection http = new CustomHttpURLConnection();
−
  BufferedReader reader = null;
+
HashMap<String, String> params = new HashMap<String, String>();
−
  try {
+
params.put("errorlog", stackTrace);
−
      URL url = new URL(strGetUrl);
+
http.setParams(params);
−
      urlConn = (HttpURLConnection) url.openConnection();
+
http.execPost("https://api.github.com/feeds");
−
      urlConn.addRequestProperty("Content-Type", "application/json; charset=UTF-8");
+
</pre>
−
      urlConn.setRequestMethod("GET");
+
 
−
//     urlConn.setRequestMethod("POST");
+
CustomHttpURLConnection.java
−
      urlConn.setConnectTimeout(10000); // 10s
+
<pre>
−
      urlConn.setReadTimeout(1000); // 1s
+
import java.io.BufferedReader;
−
      urlConn.connect();
+
import java.io.IOException;
−
      int status = urlConn.getResponseCode();
+
import java.io.InputStream;
−
      Log.i("HttpURLConnection","status_code=" + status);
+
import java.io.InputStreamReader;
−
      if (status == HttpURLConnection.HTTP_OK) {
+
import java.io.OutputStream;
−
          in = urlConn.getInputStream();
+
import java.io.PrintWriter;
−
          reader = new BufferedReader(new InputStreamReader(in));
+
import java.net.HttpURLConnection;
−
          StringBuilder output = new StringBuilder();
+
import java.net.SocketTimeoutException;
−
          String line;
+
import java.net.URL;
−
          while ((line = reader.readLine()) != null) {
+
import java.util.HashMap;
−
              output.append(line);
+
import java.util.Set;
−
          }
+
import android.net.Uri;
−
          Log.i("HttpURLConnection", "res=" + output.toString());
+
import android.util.Log;
−
      }
+
 
−
  } catch (SocketTimeoutException e) {
+
class CustomHttpURLConnection
−
      e.printStackTrace();
+
{
−
  } catch (IOException e) {
+
    HttpURLConnection urlConn = null;
−
      e.printStackTrace();
+
    HashMap<String,String> mParams = new HashMap<String,String>();
−
  } finally {
+
    String body = "";
−
      try {
+
    public void setParams(HashMap<String,String> params) {
−
          if (reader != null) {
+
        mParams = params;
−
              reader.close();
+
    }
−
          }
+
    public void execGet(String strUrl) {
−
          if (urlConn != null) {
+
        // System.setProperty("http.agent", "Dalvik/2.1.0 (Linux; U; Android 9; H8216 Build/PDP-PKQ1.180708.001-10229)"); // System.getProperty("http.agent");
−
              urlConn.disconnect();
+
        Log.i("HttpURLConnection", "ua=" + System.getProperty("http.agent"));
−
          }
+
        InputStream in = null;
−
      } catch (IOException e) {
+
        BufferedReader reader = null;
−
          e.printStackTrace();
+
        try {
−
      }
+
            if (mParams.size() > 0) {
−
  }
+
                Uri.Builder builder = new Uri.Builder();
 +
                Set keys  = mParams.keySet();
 +
                for (Object key : keys) {
 +
                    builder.appendQueryParameter((String) key, mParams.get((String) key));
 +
                }
 +
                String join = builder.build().getEncodedQuery();
 +
                Log.i("HttpURLConnection", "join=" + join);
 +
                strUrl = strUrl + "?" + join;
 +
            }
 +
            Log.i("HttpURLConnection", "url=" + strUrl);
 +
            URL url = new URL(strUrl);
 +
            urlConn = (HttpURLConnection) url.openConnection();
 +
            urlConn.addRequestProperty("Content-Type", "application/json; charset=UTF-8");
 +
            urlConn.setRequestMethod("GET");
 +
            urlConn.setConnectTimeout(10000); // 10s
 +
            urlConn.setReadTimeout(1000); // 1s
 +
            urlConn.connect();
 +
            int status = urlConn.getResponseCode();
 +
            Log.i("HttpURLConnection", "status_code=" + status);
 +
            if (status == HttpURLConnection.HTTP_OK) {
 +
                in = urlConn.getInputStream();
 +
                reader = new BufferedReader(new InputStreamReader(in));
 +
                StringBuilder output = new StringBuilder();
 +
                String line;
 +
                while ((line = reader.readLine()) != null) {
 +
                    output.append(line);
 +
                }
 +
                Log.i("HttpURLConnection", "res=" + output.toString());
 +
                body = output.toString();
 +
            }
 +
        } catch (SocketTimeoutException e) {
 +
            e.printStackTrace();
 +
        } catch (IOException e) {
 +
            e.printStackTrace();
 +
        } finally {
 +
            try {
 +
                if (reader != null) {
 +
                    reader.close();
 +
                }
 +
                if (urlConn != null) {
 +
                    urlConn.disconnect();
 +
                }
 +
            } catch (IOException e) {
 +
                e.printStackTrace();
 +
            }
 +
        }
 +
    }
 +
    public void execPost(String strUrl) {
 +
        // System.setProperty("http.agent", "Dalvik/2.1.0 (Linux; U; Android 9; H8216 Build/PDP-PKQ1.180708.001-10229)"); // System.getProperty("http.agent");
 +
        Log.i("HttpURLConnection", "ua=" + System.getProperty("http.agent"));
 +
        HttpURLConnection urlConn = null;
 +
        InputStream in = null;
 +
        BufferedReader reader = null;
 +
        try {
 +
            URL url = new URL(strUrl);
 +
            urlConn = (HttpURLConnection) url.openConnection();
 +
            urlConn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
 +
            urlConn.setRequestMethod("POST");
 +
            urlConn.setConnectTimeout(10000); // 10s
 +
            urlConn.setReadTimeout(1000); // 1s
 +
            urlConn.setInstanceFollowRedirects(false);
 +
            urlConn.setRequestProperty("Accept-Language", "jp");
 +
            urlConn.setDoOutput(true);
 +
            OutputStream outputStream = urlConn.getOutputStream();
 +
            Log.i("HttpURLConnection", "mParams.size()=" + mParams.size());
 +
            if (mParams.size() > 0) {
 +
                Uri.Builder builder = new Uri.Builder();
 +
                Set keys  = mParams.keySet();
 +
                for (Object key : keys) {
 +
                    builder.appendQueryParameter((String) key, mParams.get((String) key));
 +
                }
 +
                String join = builder.build().getEncodedQuery();
 +
                Log.i("HttpURLConnection", "join=" + join);
 +
                PrintWriter ps = new PrintWriter(outputStream);
 +
                ps.print(join);
 +
                ps.close();
 +
            }
 +
            outputStream.close();
 +
            int status = urlConn.getResponseCode();
 +
            String resmessage = urlConn.getResponseMessage();
 +
            Log.i("HttpURLConnection", "status_code=" + status);
 +
            Log.i("HttpURLConnection", "message=" + resmessage);
 +
            if (status == HttpURLConnection.HTTP_OK) {
 +
                in = urlConn.getInputStream();
 +
                reader = new BufferedReader(new InputStreamReader(in));
 +
                StringBuilder output = new StringBuilder();
 +
                String line;
 +
                while ((line = reader.readLine()) != null) {
 +
                    output.append(line);
 +
                }
 +
                Log.i("HttpURLConnection", "res=" + output.toString());
 +
                body = output.toString();
 +
            }
 +
        } catch (SocketTimeoutException e) {
 +
            e.printStackTrace();
 +
        } catch (IOException e) {
 +
            e.printStackTrace();
 +
        } finally {
 +
            try {
 +
                if (reader != null) {
 +
                    reader.close();
 +
                }
 +
                if (urlConn != null) {
 +
                    urlConn.disconnect();
 +
                }
 +
            } catch (IOException e) {
 +
                e.printStackTrace();
 +
            }
 +
        }
 +
    }
 +
    public String getBody() {
 +
        return body;
 +
    }
 +
}
 +
</pre>
 +
 
 +
post時の参考：https://araramistudio.jimdo.com/2018/03/15/android%E3%81%A7http%E3%82%92%E4%BD%BF%E3%81%A3%E3%81%9F%E3%83%8D%E3%83%83%E3%83%88%E3%83%AF%E3%83%BC%E3%82%AF%E6%8E%A5%E7%B6%9A/
 +
 
 +
urlConn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); はjsonでなくpost時はこんな感じにしないとならない。
  
 
uaはサーバに接続して変更設定されていることを確認済み。
 
uaはサーバに接続して変更設定されていることを確認済み。
行94: 行212:
 
     }
 
     }
 
</pre>
 
</pre>
 +
 +
==AsyncTask経由==
 +
<pre>
 +
import android.app.Activity;
 +
import android.content.Context;
 +
import android.content.DialogInterface;
 +
import android.content.DialogInterface.OnCancelListener;
 +
import android.os.AsyncTask;
 +
import android.util.Log;
 +
import java.io.UnsupportedEncodingException;
 +
import java.net.URLEncoder;
 +
/*
 +
HttpAsyncTask task = new HttpAsyncTask();
 +
task.setParam1("hoge");
 +
task.execute();
 +
*/
 +
public class HttpAsyncTask extends AsyncTask<String, Integer, Long>
 +
        implements OnCancelListener {
 +
    private final String TAG = "MyAsyncTask";
 +
    private Context mContext;
 +
    private Activity mActivity;
 +
    private String param1;
 +
    public HttpAsyncTask(Context context) {
 +
        this.mContext = context;
 +
    }
 +
    public void setActivity(Activity activity) {
 +
        mActivity = activity;
 +
    }
 +
    public void setParam1(String str) {
 +
        this.param1 = str;
 +
    }
 +
    @Override
 +
    protected void onPreExecute() {
 +
        Log.d(TAG, "onPreExecute");
 +
    }
 +
    @Override
 +
    protected Long doInBackground(String... urls) {
 +
        CustomHttpURLConnection http = new CustomHttpURLConnection();
 +
        try {
 +
            String encode = URLEncoder.encode(param1, "UTF-8");
 +
            String url = "ttps://hoge.example.com/hoge?param1=" + encode;
 +
            http.execGet(url);
 +
            Log.d(TAG, url);
 +
        } catch (UnsupportedEncodingException e) {
 +
            e.printStackTrace();
 +
        }
 +
        return 123L;
 +
    }
 +
    @Override
 +
    protected void onProgressUpdate(Integer... values) {
 +
        Log.d(TAG, "onProgressUpdate=" + values[0]);
 +
    }
 +
    @Override
 +
    protected void onCancelled() {
 +
        Log.d(TAG, "onCancelled");
 +
    }
 +
    @Override
 +
    protected void onPostExecute(Long result) {
 +
        Log.d(TAG, "onPostExecute=" + result);
 +
    }
 +
    public void onCancel(DialogInterface dialog) {
 +
        Log.d(TAG, "Dialog onCancell... calling cancel(true)");
 +
        this.cancel(true);
 +
    }
 +
}
 +
</pre>
 +
 +
-MainActivity.java
 +
<pre>
 +
HttpAsyncTask task = new HttpAsyncTask();
 +
task.setParam1("hoge");
 +
task.execute();
 +
try {
 +
    task.get(); // awaitのように待機待ちする場合はget()で待機待できる
 +
} catch (ExecutionException e) {
 +
    e.printStackTrace();
 +
} catch (InterruptedException e) {
 +
    e.printStackTrace();
 +
}
 +
</pre>
 +
 +
==ThreadRunnable経由==
 +
-MainActivity.java
 +
<pre>
 +
HandlerThread thread = new HandlerThread("other");
 +
thread.start();
 +
final Handler handler = new Handler(thread.getLooper());
 +
new Thread(new Runnable() {
 +
    @Override
 +
    public void run() {
 +
        if (handler != null) {
 +
            handler.post(new Runnable() {
 +
                @Override
 +
                public void run() {
 +
                    CustomHttpURLConnection http = new CustomHttpURLConnection();
 +
                    try {
 +
                        String encode = URLEncoder.encode(param1, "UTF-8");
 +
                        String url = "ttps://example.com/hoge?param1=" + encode;
 +
                        http.execGet(url);
 +
                        Log.i("test", http.getBody());
 +
                        Log.d("test", url);
 +
                    } catch (UnsupportedEncodingException e) {
 +
                        e.printStackTrace();
 +
                    }
 +
                }
 +
            });
 +
        }
 +
    }
 +
}).start();
 +
</pre>
 +
 +
===android.os.NetworkOnMainThreadExceptionエラーが出る場合===
 +
UIThreadでネットワークにアクセスするとそうなるので、
 +
<pre>
 +
HandlerThread thread = new HandlerThread("other");
 +
thread.start();
 +
final Handler handler = new Handler(thread.getLooper());
 +
</pre>
 +
が
 +
Handler handler = new Handler(Looper.getMainLooper());
 +
になってないか確認する。
 +
 +
==戻り値を受けたい場合==
 +
Listenerを使うとか、CountDownLatchを使うとか。
 +
 +
CountDownLatchの参考
 +
 +
https://docs.oracle.com/javase/jp/8/docs/api/java/util/concurrent/CountDownLatch.html
 +
 +
https://qiita.com/maromaro3721/items/c9e16068d13e8ca217f5
 +
 +
==Causee: java.security.cert.CertificateException: Chain validation failedエラーが出るとき==
 +
自己署名証明書を通すように。
 +
参考：https://www.it-swarm.dev/ja/android/okhttp%E3%82%92%E4%BD%BF%E7%94%A8%E3%81%97%E3%81%A6%E3%81%99%E3%81%B9%E3%81%A6%E3%81%AE%E8%A8%BC%E6%98%8E%E6%9B%B8%E3%82%92%E4%BF%A1%E9%A0%BC%E3%81%99%E3%82%8B/1048177852/
 +
 +
以下add分を追加すればよい。
 +
<pre>
 +
URL url = new URL(url);
 +
urlConn = (HttpsURLConnection) url.openConnection();
 +
urlConn.setRequestMethod("GET");
 +
// add start
 +
TrustManager[] trustAllCerts = new TrustManager[] {
 +
        new X509TrustManager() {
 +
            @Override
 +
            public X509Certificate[] getAcceptedIssuers() {
 +
                return new X509Certificate[] {};
 +
            }
 +
 +
            @Override
 +
            public void checkClientTrusted(X509Certificate[] chain, String authType)
 +
                    throws CertificateException {
 +
            }
 +
 +
            @Override
 +
            public void checkServerTrusted(X509Certificate[] chain, String authType)
 +
                    throws CertificateException {
 +
            }
 +
        }
 +
};
 +
SSLContext ctx = SSLContext.getInstance("TLS");
 +
ctx.init(null, trustAllCerts, new SecureRandom());
 +
SSLSocketFactory factory = ctx.getSocketFactory();
 +
urlConn.setSSLSocketFactory(factory);
 +
// add end
 +
urlConn.connect();
 +
</pre>
 +
 +
===openStreamで起こる場合===
 +
以下のように、urlのopenStrem()を削除してHttpsURLConnectionのgetInputStream()を追加して、上記項目のように、TLSの記述をHttpsURLConnectionへ追加する。
 +
<pre>
 +
URL url = new URL(url);
 +
- is = url.openStream();
 +
HttpsURLConnection urlConn = (HttpsURLConnection)u.openConnection();
 +
+ is = urlConn.getInputStream();
 +
</pre>
 +
 +
===KitKat(4.4)でSSLのConnection reset by peerエラーが出るとき===
 +
以下エラーが出るとき
 +
<pre>
 +
Error Msg: SSL handshake aborted: ssl=0x761439c0: I/O error during system call, Connection reset by peer
 +
</pre>
 +
以下を入れると直った。
 +
<pre>
 +
try {
 +
        ProviderInstaller.installIfNeeded(mContext.getApplicationContext());
 +
} catch (GooglePlayServicesRepairableException e) {
 +
        e.printStackTrace();
 +
} catch (GooglePlayServicesNotAvailableException e) {
 +
        e.printStackTrace();
 +
}
 +
</pre>
 +
参考：https://www.it-swarm.dev/ja/android/javaxnetsslsslexception%EF%BC%9Aandroid%E5%8F%A4%E3%81%84%E3%83%87%E3%83%90%E3%82%A4%E3%82%B9%E3%81%A7ssl%E3%83%8F%E3%83%B3%E3%83%89%E3%82%B7%E3%82%A7%E3%82%A4%E3%82%AF%E3%81%8C%E4%B8%AD%E6%AD%A2%E3%81%95%E3%82%8C%E3%81%BE%E3%81%97%E3%81%9F/829670631/

2020年9月4日 (金) 15:23時点における最新版

準備

AndroidManifest.xml 

<uses-permission android:name="android.permission.INTERNET" />

サンプル

同期処理のみ(AsyncTaskなどで実行すること)

get 

CustomHttpURLConnection http = new CustomHttpURLConnection();
HashMap<String, String> params = new HashMap<String, String>();
params.put("errorlog", stackTrace);
http.setParams(params);
http.execGet("https://api.github.com/feeds");

post 

CustomHttpURLConnection http = new CustomHttpURLConnection();
HashMap<String, String> params = new HashMap<String, String>();
params.put("errorlog", stackTrace);
http.setParams(params);
http.execPost("https://api.github.com/feeds");

CustomHttpURLConnection.java 

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.SocketTimeoutException;
import java.net.URL;
import java.util.HashMap;
import java.util.Set;
import android.net.Uri;
import android.util.Log;

class CustomHttpURLConnection
{
    HttpURLConnection urlConn = null;
    HashMap<String,String> mParams = new HashMap<String,String>();
    String body = "";
    public void setParams(HashMap<String,String> params) {
        mParams = params;
    }
    public void execGet(String strUrl) {
        // System.setProperty("http.agent", "Dalvik/2.1.0 (Linux; U; Android 9; H8216 Build/PDP-PKQ1.180708.001-10229)"); // System.getProperty("http.agent");
        Log.i("HttpURLConnection", "ua=" + System.getProperty("http.agent"));
        InputStream in = null;
        BufferedReader reader = null;
        try {
            if (mParams.size() > 0) {
                Uri.Builder builder = new Uri.Builder();
                Set keys  = mParams.keySet();
                for (Object key : keys) {
                    builder.appendQueryParameter((String) key, mParams.get((String) key));
                }
                String join = builder.build().getEncodedQuery();
                Log.i("HttpURLConnection", "join=" + join);
                strUrl = strUrl + "?" + join;
            }
            Log.i("HttpURLConnection", "url=" + strUrl);
            URL url = new URL(strUrl);
            urlConn = (HttpURLConnection) url.openConnection();
            urlConn.addRequestProperty("Content-Type", "application/json; charset=UTF-8");
            urlConn.setRequestMethod("GET");
            urlConn.setConnectTimeout(10000); // 10s
            urlConn.setReadTimeout(1000); // 1s
            urlConn.connect();
            int status = urlConn.getResponseCode();
            Log.i("HttpURLConnection", "status_code=" + status);
            if (status == HttpURLConnection.HTTP_OK) {
                in = urlConn.getInputStream();
                reader = new BufferedReader(new InputStreamReader(in));
                StringBuilder output = new StringBuilder();
                String line;
                while ((line = reader.readLine()) != null) {
                    output.append(line);
                }
                Log.i("HttpURLConnection", "res=" + output.toString());
                body = output.toString();
            }
        } catch (SocketTimeoutException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (reader != null) {
                    reader.close();
                }
                if (urlConn != null) {
                    urlConn.disconnect();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    public void execPost(String strUrl) {
        // System.setProperty("http.agent", "Dalvik/2.1.0 (Linux; U; Android 9; H8216 Build/PDP-PKQ1.180708.001-10229)"); // System.getProperty("http.agent");
        Log.i("HttpURLConnection", "ua=" + System.getProperty("http.agent"));
        HttpURLConnection urlConn = null;
        InputStream in = null;
        BufferedReader reader = null;
        try {
            URL url = new URL(strUrl);
            urlConn = (HttpURLConnection) url.openConnection();
            urlConn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            urlConn.setRequestMethod("POST");
            urlConn.setConnectTimeout(10000); // 10s
            urlConn.setReadTimeout(1000); // 1s
            urlConn.setInstanceFollowRedirects(false);
            urlConn.setRequestProperty("Accept-Language", "jp");
            urlConn.setDoOutput(true);
            OutputStream outputStream = urlConn.getOutputStream();
            Log.i("HttpURLConnection", "mParams.size()=" + mParams.size());
            if (mParams.size() > 0) {
                Uri.Builder builder = new Uri.Builder();
                Set keys  = mParams.keySet();
                for (Object key : keys) {
                    builder.appendQueryParameter((String) key, mParams.get((String) key));
                }
                String join = builder.build().getEncodedQuery();
                Log.i("HttpURLConnection", "join=" + join);
                PrintWriter ps = new PrintWriter(outputStream);
                ps.print(join);
                ps.close();
            }
            outputStream.close();
            int status = urlConn.getResponseCode();
            String resmessage = urlConn.getResponseMessage();
            Log.i("HttpURLConnection", "status_code=" + status);
            Log.i("HttpURLConnection", "message=" + resmessage);
            if (status == HttpURLConnection.HTTP_OK) {
                in = urlConn.getInputStream();
                reader = new BufferedReader(new InputStreamReader(in));
                StringBuilder output = new StringBuilder();
                String line;
                while ((line = reader.readLine()) != null) {
                    output.append(line);
                }
                Log.i("HttpURLConnection", "res=" + output.toString());
                body = output.toString();
            }
        } catch (SocketTimeoutException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (reader != null) {
                    reader.close();
                }
                if (urlConn != null) {
                    urlConn.disconnect();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    public String getBody() {
        return body;
    }
}

post時の参考：https://araramistudio.jimdo.com/2018/03/15/android%E3%81%A7http%E3%82%92%E4%BD%BF%E3%81%A3%E3%81%9F%E3%83%8D%E3%83%83%E3%83%88%E3%83%AF%E3%83%BC%E3%82%AF%E6%8E%A5%E7%B6%9A/

urlConn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); はjsonでなくpost時はこんな感じにしないとならない。

uaはサーバに接続して変更設定されていることを確認済み。

ドメイン接続許可しないエラーが出るときはこちらを確認

android/開発環境/Android8 [ｼｮｰﾄｶｯﾄ]

参考

https://itsakura.com/java-httpurlconnection

http://d.hatena.ne.jp/Kazuhira/20131026/1382796711

uaを設定しない場合とwebviewからもてっくる場合

HttpURLConnectionのuaデフォ(System.getProperty("http.agent");) 

Dalvik/2.1.0 (Linux; U; Android 9; Pixel 2 XL Build/PPR2.181005.003)

webviewのua android/webview/useragent [ｼｮｰﾄｶｯﾄ] 

Mozilla/5.0 (Linux; Android 9; Pixel 2 XL Build/PPR2.181005.003; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/70.0.3538.110 Mobile Safari/537.36

retry処理

本来のget処理をexecGetCore()に入れる 

    public boolean execGet() throws Exception {
        Exception tmpException = null;
        for (int retry = 0; retry <= mRetry; retry++) {
            try {
                boolean ret = execGetCore();
                if (ret) {
                    return ret;
                }
            } catch (Exception e) {
                tmpException = e;
            }
        }
        if (Exception != null) {
            throw tmpException;
        }
        return false;
    }

AsyncTask経由

import android.app.Activity;
import android.content.Context;
import android.content.DialogInterface;
import android.content.DialogInterface.OnCancelListener;
import android.os.AsyncTask;
import android.util.Log;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
/*
HttpAsyncTask task = new HttpAsyncTask();
task.setParam1("hoge");
task.execute();
*/
public class HttpAsyncTask extends AsyncTask<String, Integer, Long>
        implements OnCancelListener {
    private final String TAG = "MyAsyncTask";
    private Context mContext;
    private Activity mActivity;
    private String param1;
    public HttpAsyncTask(Context context) {
        this.mContext = context;
    }
    public void setActivity(Activity activity) {
        mActivity = activity;
    }
    public void setParam1(String str) {
        this.param1 = str;
    }
    @Override
    protected void onPreExecute() {
        Log.d(TAG, "onPreExecute");
    }
    @Override
    protected Long doInBackground(String... urls) {
        CustomHttpURLConnection http = new CustomHttpURLConnection();
        try {
            String encode = URLEncoder.encode(param1, "UTF-8");
            String url = "ttps://hoge.example.com/hoge?param1=" + encode;
            http.execGet(url);
            Log.d(TAG, url);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return 123L;
    }
    @Override
    protected void onProgressUpdate(Integer... values) {
        Log.d(TAG, "onProgressUpdate=" + values[0]);
    }
    @Override
    protected void onCancelled() {
        Log.d(TAG, "onCancelled");
    }
    @Override
    protected void onPostExecute(Long result) {
        Log.d(TAG, "onPostExecute=" + result);
    }
    public void onCancel(DialogInterface dialog) {
        Log.d(TAG, "Dialog onCancell... calling cancel(true)");
        this.cancel(true);
    }
}

-MainActivity.java 

HttpAsyncTask task = new HttpAsyncTask();
task.setParam1("hoge");
task.execute();
try {
    task.get(); // awaitのように待機待ちする場合はget()で待機待できる
} catch (ExecutionException e) {
    e.printStackTrace();
} catch (InterruptedException e) {
    e.printStackTrace();
}

ThreadRunnable経由

-MainActivity.java 

HandlerThread thread = new HandlerThread("other");
thread.start();
final Handler handler = new Handler(thread.getLooper());
new Thread(new Runnable() {
    @Override
    public void run() {
        if (handler != null) {
            handler.post(new Runnable() {
                @Override
                public void run() {
                    CustomHttpURLConnection http = new CustomHttpURLConnection();
                    try {
                        String encode = URLEncoder.encode(param1, "UTF-8");
                        String url = "ttps://example.com/hoge?param1=" + encode;
                        http.execGet(url);
                        Log.i("test", http.getBody());
                        Log.d("test", url);
                    } catch (UnsupportedEncodingException e) {
                        e.printStackTrace();
                    }
                }
            });
        }
    }
}).start();

android.os.NetworkOnMainThreadExceptionエラーが出る場合

UIThreadでネットワークにアクセスするとそうなるので、 

HandlerThread thread = new HandlerThread("other");
thread.start();
final Handler handler = new Handler(thread.getLooper());

が 

Handler handler = new Handler(Looper.getMainLooper());

になってないか確認する。

戻り値を受けたい場合

Listenerを使うとか、CountDownLatchを使うとか。

CountDownLatchの参考

https://docs.oracle.com/javase/jp/8/docs/api/java/util/concurrent/CountDownLatch.html

https://qiita.com/maromaro3721/items/c9e16068d13e8ca217f5

Causee: java.security.cert.CertificateException: Chain validation failedエラーが出るとき

自己署名証明書を通すように。 参考：https://www.it-swarm.dev/ja/android/okhttp%E3%82%92%E4%BD%BF%E7%94%A8%E3%81%97%E3%81%A6%E3%81%99%E3%81%B9%E3%81%A6%E3%81%AE%E8%A8%BC%E6%98%8E%E6%9B%B8%E3%82%92%E4%BF%A1%E9%A0%BC%E3%81%99%E3%82%8B/1048177852/

以下add分を追加すればよい。 

URL url = new URL(url);
urlConn = (HttpsURLConnection) url.openConnection();
urlConn.setRequestMethod("GET");
// add start
TrustManager[] trustAllCerts = new TrustManager[] {
        new X509TrustManager() {
            @Override
            public X509Certificate[] getAcceptedIssuers() {
                return new X509Certificate[] {};
            }

            @Override
            public void checkClientTrusted(X509Certificate[] chain, String authType)
                    throws CertificateException {
            }

            @Override
            public void checkServerTrusted(X509Certificate[] chain, String authType)
                    throws CertificateException {
            }
        }
};
SSLContext ctx = SSLContext.getInstance("TLS");
ctx.init(null, trustAllCerts, new SecureRandom());
SSLSocketFactory factory = ctx.getSocketFactory();
urlConn.setSSLSocketFactory(factory);
// add end
urlConn.connect();

openStreamで起こる場合

以下のように、urlのopenStrem()を削除してHttpsURLConnectionのgetInputStream()を追加して、上記項目のように、TLSの記述をHttpsURLConnectionへ追加する。 

URL url = new URL(url);
- is = url.openStream();
HttpsURLConnection urlConn = (HttpsURLConnection)u.openConnection();
+ is = urlConn.getInputStream();

KitKat(4.4)でSSLのConnection reset by peerエラーが出るとき

以下エラーが出るとき 

Error Msg: SSL handshake aborted: ssl=0x761439c0: I/O error during system call, Connection reset by peer

以下を入れると直った。 

try {
        ProviderInstaller.installIfNeeded(mContext.getApplicationContext());
} catch (GooglePlayServicesRepairableException e) {
        e.printStackTrace();
} catch (GooglePlayServicesNotAvailableException e) {
        e.printStackTrace();
}

参考：https://www.it-swarm.dev/ja/android/javaxnetsslsslexception%EF%BC%9Aandroid%E5%8F%A4%E3%81%84%E3%83%87%E3%83%90%E3%82%A4%E3%82%B9%E3%81%A7ssl%E3%83%8F%E3%83%B3%E3%83%89%E3%82%B7%E3%82%A7%E3%82%A4%E3%82%AF%E3%81%8C%E4%B8%AD%E6%AD%A2%E3%81%95%E3%82%8C%E3%81%BE%E3%81%97%E3%81%9F/829670631/

「http://wiki.nonip.net/index.php?title=Android/HttpRequest通信/HttpURLConnection&oldid=11979」から取得