Android:从Php网页获取空字符串

时间:2012-05-02 22:24:25

标签: php android web-services

我有两个应用程序,一个是我发送的。和纬度坐标到一个PHP文件,另一个应用程序检索长。和拉特。 COORDS。为了测试并看看我是否可以获得第一个工作,我创建了一个函数,我发布了纬度和长度。 coords两个P​​HP服务,我把它们放回到同一个应用程序中。我把它们放在烤面包上,看它是否有效。我甚至实现了位置监听器来上传坐标并在同一个应用程序中检索它们以进行测试,然后再尝试在其他应用程序中接收它们。它工作正常。但是当我尝试在其他应用程序中使用相同的代码来接收坐标时,我会收到空​​白坐标。我调试了它,它只是空白,好像当我从其他应用程序调用服务器时,它会删除php服务中的当前值。

将坐标放在应用程序1中的代码:

public void postData(String longCord, String latCord) throws JSONException{  
    // Create a new HttpClient and Post Header
    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost(".../android/serverFile.php");
    JSONObject json = new JSONObject();

    try {
        // JSON data:
        json.put("longitude", longCord);
        json.put("latitude", latCord);
        JSONArray postjson=new JSONArray();
        postjson.put(json);

        // Post the data:
        httppost.setHeader("json",json.toString());
        httppost.getParams().setParameter("jsonpost",postjson);
        // Execute HTTP Post Request
        //System.out.print(json);
        HttpResponse response = httpclient.execute(httppost);

        // for JSON:
        if(response != null)
        {

            InputStream is = response.getEntity().getContent();
            BufferedReader reader = new BufferedReader(new InputStreamReader(is));
            StringBuilder sb = new StringBuilder();
            String line = null;
            try {
                while ((line = reader.readLine()) != null) {
                    sb.append(line + "\n");
                }
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
                                    JSONObject jsonObj = new JSONObject(jsonStr);
                // grabbing the menu object 
                String longitudecord = jsonObj.getString("lon");
                String latitudecord = jsonObj.getString("lat");

                Toast.makeText( getApplicationContext(),longitudecord,Toast.LENGTH_SHORT).show();
                Toast.makeText( getApplicationContext(),latitudecord,Toast.LENGTH_SHORT).show();
        }

    }catch (ClientProtocolException e) {
        // TODO Auto-generated catch block
    } catch (IOException e) {
        // TODO Auto-generated catch block
    }
}

php文件:

<?php
$json = $_SERVER['HTTP_JSON'];
$data = json_decode($json);
$lon = $data->longitude;
$lat = $data->latitude;
$variable = array( 'lon' => "$lon", 'lat' => "$lat" );
// One JSON for both variables
echo json_encode($variable);

&GT;

现在当我在另一个应用程序上运行此代码时...它与上面相同减去发布坐标...我得到lon:“”和lat:“”。有点像通过发出请求它以某种方式删除其他应用程序发布的信息。是这种情况吗?

 public void recieveData() throws JSONException{  
        // Create a new HttpClient and Post Header
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost(".../android/serverFile.php");
        try {
            HttpResponse response = httpclient.execute(httppost);
            // for JSON:
            if(response != null)
            {
                InputStream is = response.getEntity().getContent();
                BufferedReader reader = new BufferedReader(new InputStreamReader(is));
                StringBuilder sb = new StringBuilder();
                String line = null;
                try {
                    while ((line = reader.readLine()) != null) {
                        sb.append(line + "\n");
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    try {
                        is.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                String jsonStr = sb.toString();
                JSONObject jsonObj = new JSONObject(jsonStr);
                // grabbing the menu object 
                String longitudecord = jsonObj.getString("lon");
                String latitudecord = jsonObj.getString("lat");

                Toast.makeText( getApplicationContext(),longitudecord,Toast.LENGTH_SHORT).show();
                Toast.makeText( getApplicationContext(),jsonStr,Toast.LENGTH_SHORT).show();
            }

1 个答案:

答案 0 :(得分:1)

尝试在浏览器中访问您的网址,并确保您的PHP脚本在以下行中没有出现任何错误(因为您没有在第二个应用程序中提供任何JSON输入):

$data = json_decode($json);
$lon = $data->longitude;
$lat = $data->latitude;

另外,很高兴听到,您如何保存服务器上的lat / lon,以便它们在通话之间保持不变。

例如,您可以使用此PHP代码:

$db_host = "localhost";
$db_name = "********";
$db_user = "********";
$db_pass = "********";

// connect to MySQL
$db = mysql_connect($db_host, $db_user, $db_pass);
if( !$db ) {
    die( 'Unable to connect to server : ' . mysql_error() );
}

// select the DB
if( !mysql_select_db($db_name) ) {
    die( 'Unable to select DB : ' . mysql_error() );
}

// create table, if not exists
if( !mysql_query( "CREATE TABLE IF NOT EXISTS `locations` (
    `id` int(11) NOT NULL auto_increment,
    `latitude` double NOT NULL COMMENT 'latitude',
    `longitude` double NOT NULL COMMENT 'longitude',
    PRIMARY KEY  (`id`)
    ) ENGINE=MyISAM  DEFAULT CHARSET=utf8;"
) ) {
    die( 'Unable to create table : ' . mysql_error() );
}

// save values
mysql_query( "INSERT INTO locations (`latitude`, `longitude`) VALUES ( '$lat', '$lon')" );

// read them back
$track = array()
$result = mysql_query( "SELECT * FROM locations" );
while( $data = mysql_fetch_assoc($result) ) {
    $track[] = array(
        'latitude' => $data['latitude'],
        'longitude' => $data['longitude'] );
}

// here you may convert `track` into JSON / XML and send coordinates list to your application