我一直在尝试使用多个示例通过Android应用程序访问远程服务器（digitalocean）。目前我在解析URL中的数据时遇到错误，我不是100％确定原因。你能帮帮我吗，代码如下。
java代码：
public class MainActivity extends Activity {
TextView txt1,txt2,txt3;
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new task().execute();
}
class task extends AsyncTask<String, String, Void>
{
private ProgressDialog progressDialog = new ProgressDialog(MainActivity.this);
InputStream is = null ;
String result = "";
protected void onPreExecute() {
progressDialog.setMessage("Fetching data...");
progressDialog.show();
progressDialog.setOnCancelListener(new OnCancelListener() {
@Override
public void onCancel(DialogInterface arg0) {
task.this.cancel(true);
}
});
}
@Override
protected Void doInBackground(String... params) {
String url_select = "http://server1.chris.waszczuk/webservice/select.php";
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url_select);
ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();
try {
httpPost.setEntity(new UrlEncodedFormEntity(param));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
//read content
is = httpEntity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection "+e.toString());
}
try {
BufferedReader br = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = "";
while((line=br.readLine())!=null)
{
sb.append(line+"\n");
}
is.close();
result=sb.toString();
} catch (Exception e) {
// TODO: handle exception
Log.e("log_tag", "Error converting result "+e.toString());
}
return null;
}
protected void onPostExecute(Void v) {
// ambil data dari Json database
try {
JSONArray Jarray = new JSONArray(result);
for(int i=0;i<Jarray.length();i++)
{
JSONObject Jasonobject = null;
txt1 = (TextView)findViewById(R.id.txt1);
txt2 = (TextView)findViewById(R.id.txt2);
txt3 = (TextView)findViewById(R.id.txt3);
Jasonobject = Jarray.getJSONObject(i);
//get an output on the screen
String no = Jasonobject.getString("no// this should be same in the table field name");
String name = Jasonobject.getString("name");
String birthday = Jasonobject.getString("birthday");
txt1.setText(no);
txt2.setText(name);
txt3.setText(birthday);
}
this.progressDialog.dismiss();
} catch (Exception e) {
// TODO: handle exception
Log.e("log_tag", "Error parsing data "+e.toString());
}
}
}
}
XML代码:(互联网权限在清单中（无需上传））
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<LinearLayout android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:orientation="horizontal"
android:layout_marginTop="10dp">
<TextView android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="Id Number:"
android:textStyle="bold"
android:gravity="center"
android:textSize="15dp"
android:layout_marginLeft="15dp" />
<TextView android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:id="@+id/txt1"
android:layout_marginLeft="20dp"/>
</LinearLayout>
<LinearLayout android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:orientation="horizontal"
android:layout_marginTop="10dp">
<TextView android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text=" userName:"
android:textStyle="bold"
android:gravity="center"
android:textSize="15dp"
android:layout_marginLeft="35dp"/>
<TextView android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:id="@+id/txt2"
android:layout_marginLeft="20dp"/>
</LinearLayout>
<LinearLayout android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:orientation="horizontal"
android:layout_marginTop="10dp">
<TextView android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="Password: "
android:textStyle="bold"
android:gravity="center"
android:textSize="15dp"
android:layout_marginLeft="75dp"/>
<TextView android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:id="@+id/txt3"
android:layout_marginLeft="20dp"/>
</LinearLayout>
</LinearLayout>
php文件（选择后跟连接（密码已删除）：
<?php
include_once("connection.php");
$sqlString = "select * from registration ";
$rs = mysql_query($sqlString);
if($rs)
{
while($objRs = mysql_fetch_assoc($rs))
{
$output[] = $objRs;
}
echo json_encode($output);
}
mysql_close();
?>
<?php
mysql_connect("localhost","root","");
mysql_select_db("fantasyfootball");
?>
编辑：logcat响应可能也有用：
04-01 14:01:21.730: I/dalvikvm(814): threadid=3: reacting to signal 3
04-01 14:01:22.740: W/dalvikvm(814): threadid=3: spin on suspend #1 threadid=11 (pcf=0)
04-01 14:01:22.740: D/dalvikvm(814): Temporarily moving tid 829 to fg (was 0)
04-01 14:01:22.740: D/dalvikvm(814): Temporarily raised priority on tid 829 (10 -> 0)
04-01 14:01:22.750: W/dalvikvm(814): threadid=3: spin on suspend resolved in 1018 msec
04-01 14:01:22.750: D/dalvikvm(814): Restored policy of 829 to 0
04-01 14:01:22.760: D/dalvikvm(814): Restored priority on 829 to 10
04-01 14:01:23.190: I/Choreographer(814): Skipped 41 frames! The application may be doing too much work on its main thread.
04-01 14:01:23.200: I/dalvikvm(814): Wrote stack traces to '/data/anr/traces.txt'
04-01 14:01:24.250: I/Choreographer(814): Skipped 30 frames! The application may be doing too much work on its main thread.
04-01 14:01:25.430: I/Choreographer(814): Skipped 34 frames! The application may be doing too much work on its main thread.
04-01 14:01:25.840: E/log_tag(814): Error in http connection java.net.UnknownHostException: Unable to resolve host "server1.chris.waszczuk": No address associated with hostname
04-01 14:01:25.840: E/log_tag(814): Error converting result java.lang.NullPointerException: lock == null
04-01 14:01:25.950: I/Choreographer(814): Skipped 33 frames! The application may be doing too much work on its main thread.
04-01 14:01:25.990: E/log_tag(814): Error parsing data org.json.JSONException: End of input at character 0 of
04-01 14:01:26.440: I/Choreographer(814): Skipped 46 frames! The application may be doing too much work on its main thread.
更新：将login_url更改为服务器的IP地址后，会出现新的解析错误。
新网址：
String url_select = "http://95.85.22.140/webservice/select.php";
错误：
04-01 14:19:26.206: E/log_tag(1037): Error parsing data org.json.JSONException: Value <!DOCTYPE of type java.lang.String cannot be converted to JSONArray
任何帮助都会非常感谢。
答案 0 :(得分：1)
根据我的评论中的建议，String url_select = "http://server1.chris.waszczuk/webservice/select.php";是错误的。基本上，除非您拥有自己的DNS服务器并且所有流量都通过它，否则server1.chris.waszczuk是一个错误的DNS名称。
如果您在本地网络中运行此功能，我建议您使用服务器的私有IP地址。这样您就可以使用以下内容获取您的网址：
http://192.168.1.X/webservice/select.php
如果您将其作为远程服务器运行，请改用有效的DNS。