我是初学者，当我发送post请求时，字符串返回为空（我从日志中确认）。但是当我通过hurl.it发送在线帖子请求时，它返回true（在我的情况下，这实际上是正确的）。为什么它返回空字符串我没有在我的PHP代码中发现任何错误以及android。 android代码：
package com.example.harshitbatra.hammertime;
import android.os.AsyncTask;
import android.util.Log;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
import javax.net.ssl.HttpsURLConnection;
/**
* Created by Harshit Batra on 06-07-2016.
*/
public class Signupasync extends AsyncTask<String, Void, String>
{
String username,phone,address,email,password;
String url;
private postexecutelistener myListener;
public Signupasync(postexecutelistener pel,String url,String username, String phone,String address,String email,String password )
{
myListener = pel;
this.url = url;
this.username = username;
this.phone = phone;
this.address = address;
this.email = email;
this.password = password;
}
public interface postexecutelistener
{
public void postexecutedone(String str);
}
public String connect()
{
HashMap<String,String> hash = new HashMap<>(6);
hash.put("usernamekey",username);
hash.put("phonekey",phone);
hash.put("addresskey",address);
hash.put("emailkey",email);
hash.put("passwordkey",password);
return performPostCall(url,hash);
}
public String performPostCall(String requestURL, HashMap<String, String> postDataParams)
{
URL url;
String response = "";
try
{
url = new URL(requestURL);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(15000);
conn.setConnectTimeout(15000);
conn.setRequestMethod("POST");
conn.setDoInput(true);
conn.setDoOutput(true);
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(os, "UTF-8"));
writer.write(getPostDataString(postDataParams));
writer.flush();
writer.close();
os.close();
int responseCode = conn.getResponseCode();
if (responseCode == HttpsURLConnection.HTTP_OK)
{
String line;
BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
while ((line = br.readLine()) != null)
{
response += line;
}
}
else
{
response = "";
}
}
catch (Exception e)
{
e.printStackTrace();
}
return response;
}
private String getPostDataString(HashMap<String, String> params) throws UnsupportedEncodingException
{
StringBuilder result = new StringBuilder();
boolean first = true;
for (Map.Entry<String, String> entry : params.entrySet())
{
if (first)
first = false;
else
result.append("&");
result.append(URLEncoder.encode(entry.getKey(), "UTF-8"));
result.append("=");
result.append(URLEncoder.encode(entry.getValue(), "UTF-8"));
}
Log.e("dsasd", "getPostDataString: " + result);
return result.toString();
}
@Override
protected String doInBackground(String... para)
{
return connect();
}
@Override
protected void onPostExecute(String str)
{
super.onPostExecute(str);
Log.d("jsdk", "String from signup.php " + str);
myListener.postexecutedone(str);
}
}
php代码：
$con = mysqli_connect("mysql.hostinger.in","u626717580_batra","hb99960","u626717580_mydb");
if($con)
{
$username = $_POST['usernamekey'];
$phone = $_POST['phonekey'];
$address = $_POST['addresskey'];
$email = $_POST['emailkey'];
$password = $_POST['passwordkey'];
$sql = "INSERT INTO `u626717580_mydb`.`signup` (
`username` ,
`phone` ,
`address` ,
`email` ,
`password`
)
VALUES (
'$username', '$phone', '$address', '$email', '$password'
);
";
if($username)
{
if(mysqli_query($con,$sql) )
echo "true";
else
echo "false";
}
}
日志：
W: java.net.UnknownHostException: Unable to resolve host "hb99960.esy.es": No address associated with hostname
W: at java.net.InetAddress.lookupHostByName(InetAddress.java:424)
W: at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
W: at java.net.InetAddress.getAllByName(InetAddress.java:214)
W: at com.android.okhttp.internal.Dns$1.getAllByName(Dns.java:28)
W: at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:216)
W: at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:122)
W: at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:292)
W: at com.android.okhttp.internal.http.HttpEngine.sendSocketRequest(HttpEngine.java:255)
W: at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:206)
W: at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:345)
W: at com.android.okhttp.internal.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:89)
W: at com.android.okhttp.internal.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:197)
W: at com.example.harshitbatra.hammertime.Signupasync.performPostCall(Signupasync.java:79)
W: at com.example.harshitbatra.hammertime.Signupasync.connect(Signupasync.java:58)
W: at com.example.harshitbatra.hammertime.Signupasync.doInBackground(Signupasync.java:134)
W: at com.example.harshitbatra.hammertime.Signupasync.doInBackground(Signupasync.java:26)
W: at android.os.AsyncTask$2.call(AsyncTask.java:288)
W: at java.util.concurrent.FutureTask.run(FutureTask.java:237)
W: at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
W: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
W: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
W: at java.lang.Thread.run(Thread.java:841)
W: Caused by: libcore.io.GaiException: getaddrinfo failed: EAI_NODATA (No address associated with hostname)
W: at libcore.io.Posix.getaddrinfo(Native Method)
W: at libcore.io.ForwardingOs.getaddrinfo(ForwardingOs.java:61)
W: at java.net.InetAddress.lookupHostByName(InetAddress.java:405)
W: ... 21 more
W: Caused by: libcore.io.ErrnoException: getaddrinfo failed: EINVAL (Invalid argument)
W: ... 24 more
D: String from signup.php
last line "String from signup.php" is empty.
答案 0 :(得分：1)
正如您在堆栈跟踪中看到的那样，您的Android代码无法访问托管PHP的服务器，即hb99960.esy.es。你确定你的Android设备和你正在试用的PC＆＃34; hurl.it＆＃34;是在同一个网络上。
确保您能够到达＆＃34; hb99960.esy.es＆＃34;来自设备/模拟器上的浏览器。
希望有所帮助