从Android到php输入的json

我正在尝试将数据作为json从Android发布到PHP脚本，但是它似乎没有读取我发送的数据。

.PHP

header('Content-type: application/json');
$json = file_get_contents('php://input');
print_r($json);

数据

{"Date":"2012-05-31","Device_ID":"soaptester","Time":"15:22:59","Longitude":0.33,"Latitude":51.01}

爪哇岛

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    sp = getSharedPreferences("SoapTester", Context.MODE_PRIVATE);
    setContentView(R.layout.main);
    String address = sp.getString("address", null);
    if (address == null) {
        sp.edit().putString("address", "http://192.168.0.8/lt_data/test.php").commit();
    }
    addressTextView = (EditText) findViewById(R.id.address);
    addressTextView.setOnEditorActionListener(new TextView.OnEditorActionListener() {
        @Override
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
            sp.edit().putString("address", String.valueOf(v.getText())).commit();
            return true;
        }
    });
    track = new LocationTrack();
    track.setDate("2012-05-31");
    track.setTime("15:22:59");
    track.setLatitude(51.01);
    track.setLongitude(0.33);
    track.setDevice_ID("soaptester");
    output = new Gson().toJson(track);
    outputTextView = (TextView) findViewById(R.id.output);
    outputTextView.setText(output);
}
@Override
protected void onResume() {
    super.onResume();
    addressTextView.setText(sp.getString("address", ""));
}
public void sendPost(View view) {
    ServiceResponse r = Resting.post(sp.getString("address", ""), 80, output, EncodingTypes.UTF8);
    ((TextView)findViewById(R.id.response)).setText(String.valueOf(r));
}

经过大量测试，我似乎无法找出为什么它没有从 android 应用程序接收数据。