IDmを読み取るためのシンプルな実装例

BasicNfcSampleActivity.java

package com.esperia09.android.readnfc;

import java.util.Formatter;
import java.util.Locale;

import android.app.Activity;
import android.app.PendingIntent;
import android.content.Intent;
import android.nfc.NfcAdapter;
import android.os.Bundle;
import android.widget.TextView;

public class BasicNfcSampleActivity extends Activity {

    private NfcAdapter mNfcAdapter;
    private TextView mTxt;

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

        mNfcAdapter = NfcAdapter.getDefaultAdapter(this);

        mTxt = (TextView) findViewById(R.id.txt);
    }

    @Override
    protected void onResume() {
        super.onResume();

        Intent intent = new Intent(this, getClass())
                .addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP)
                .addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        PendingIntent pIntent = PendingIntent.getActivity(this, 0, intent, 0);
        mNfcAdapter.enableForegroundDispatch(this, pIntent, null, null);
    }

    @Override
    protected void onPause() {
        super.onPause();
        mNfcAdapter.disableForegroundDispatch(this);
    }

    @Override
    protected void onNewIntent(Intent intent) {
        super.onNewIntent(intent);

        byte[] idm = intent.getByteArrayExtra(NfcAdapter.EXTRA_ID);
        String idmStr = bytesToHexString(idm);
        mTxt.setText(idmStr);

        // IDmをハッシュ化とかしてサーバへデータを送信
        
        setIntent(null);
    }

    /*
     * バイト列を16進数文字列に変換
     */
    public static String bytesToHexString(byte[] bytes) {
        StringBuilder sb = new StringBuilder(bytes.length * 2);

        Formatter formatter = new Formatter(sb);
        for (byte b : bytes) {
            formatter.format("%02x", b);
        }
        formatter.close();

        return sb.toString().toUpperCase(Locale.getDefault());
    }
}