reader.readLine（）返回NULL。
我正在尝试将值从我的android发送到PHP，然后返回结果并显示它但由于此错误而停滞不前。 数据库只有名称和密码。获取具有相同密码的所有用户名。 提前谢谢。
package com.example.my;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONObject;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.os.Bundle;
import android.os.StrictMode;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import android.os.Build;
@TargetApi(Build.VERSION_CODES.GINGERBREAD)
@SuppressLint("NewApi")
public class MainActivity extends ActionBarActivity {
String id;
InputStream is = null;
String result = null;
String line = null;
String name = null;
@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll().build();
StrictMode.setThreadPolicy(policy);
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_main);
final EditText et_p = (EditText) findViewById(R.id.etPSWD);
Button b_go = (Button) findViewById(R.id.bGO);
System.out.println("YO");
b_go.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
id = et_p.getText().toString();
go();
}
});
}
public void go() {
ArrayList<NameValuePair> pair = new ArrayList<NameValuePair>();
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://192.168.2.5/login.php");
pair.add(new BasicNameValuePair("id", id));
httppost.setEntity(new UrlEncodedFormEntity(pair));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
Log.e("pass 1", "connection success ");
} catch (Exception e) {
Log.e("Fail 1", e.toString());
System.out.println("ERROR IS" + e.toString());
Toast.makeText(getApplicationContext(), "Invalid IP Address",
Toast.LENGTH_LONG).show();
}
try {
int count = 0;
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "ISO-8859-1"), 8);
System.out.println("READERTOSTRING" + reader.toString());
StringBuilder sb = new StringBuilder();
System.out.println("RANDOM");
/*
*
* ERROR AFTER THIS
*
*/
line = reader.readLine();
System.out.println("VALUE OF LINE:"+line);
while (line != null) {
sb.append(line + "\n");
System.out.println("ROUND" + count + "--" + sb.toString());
count++;
line = reader.readLine();
}
is.close();
result = sb.toString();
System.out.println("RESULT IS " + result);
Log.e("pass 2", "connection success ");
} catch (Exception e) {
Log.e("Fail 2", e.toString());
}
try {
System.out.println("HERE0" + result);
JSONObject json_data = new JSONObject(result);
System.out.println("HERE1");
name = (json_data.getString("success"));
System.out.println("HERE1");
Toast.makeText(getBaseContext(), "Name : " + name,
Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Log.e("Fail 3", e.toString());
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
<?php
$con = mysqli_connect("localhost","root","sen","test1");
if(mysqli_connect_errno($con))
{
echo "Failed to connect ".mysqli_connect_error();
}
$name=$_GET['name'];
$password=$_GET['password'];
$result = mysqli_query($con,"SELECT name FROM users where name='$name' and password='$password'");
//$result = mysqli_query($con,"SELECT name FROM users");
while($arr = mysqli_fetch_array($result))
{
if (mysql_num_rows($result) > 0) {
$product=array();
$product["name"]=$arr["arr"];
$product["password"]=$arr["password"];
$response["success"]=1;
$response["get"]=array();
array_push($response["get"],$product);
//IF NOT TRY $output[]=$arr;
echo json_encode($response);
}
else
{
$response["success"] = 0;
$response["message"] = "No product found";
echo json_encode($response);
}
}
//print(json_encode($product));
mysqli_close($con);
?>
ERROR
04-21 13:10:44.332: I/System.out(1339): READERTOSTRINGjava.io.BufferedReader@5275e610
04-21 13:10:44.332: I/System.out(1339): RANDOM
04-21 13:10:44.336: I/System.out(1339): VALUE OF LINE:null
04-21 13:10:44.336: I/System.out(1339): RESULT IS
04-21 13:10:44.336: E/pass 2(1339): connection success
04-21 13:10:44.340: I/System.out(1339): HERE0
04-21 13:10:44.344: E/Fail 3(1339): org.json.JSONException: End of input at character 0 of
答案 0 :(得分：0)
看起来你的PHP代码可能根本没有返回任何值。我不确定这是否重要，但您不应该使用mysqli_num_rows()代替mysql_num_rows()吗？
编辑：$password=$_GET['password'];根据您的错误，您的请求中未发送“密码”值。检查输入错误，并确保实际为密码发送了一个值。
编辑2：您在Android代码（HttpPost）中使用了帖子，但是使用PHP（$_GET）。改为将$ _GET更改为$ _REQUEST或$ _POST。
编辑3：
为您的选择添加密码。您试图从结果数组中访问它而不在SQL中选择它。
$product["name"]=$arr["arr"];应为$product["name"]=$arr["name"];
编辑4：
在while循环之前移动它：$response["get"]=array();，并在while循环之后移动它：echo json_encode($response);（两者）。那么你应该有一个像这样的JSON结构：
{
"success":1,
"post":[
{"name":"Abc","password":null},
{"name":"Def","password":null},
{"name":"Ghi","password":null},
{"name":"Jkl","password":null},
{"name":"Mno","password":null}
]
}
正如您所看到的，您的结果位于名为“post”的JSONArray（由[]标记表示）中。所以像这样：
JSONArray results = json_data.getJSONObject("post");
for (int i = 0; i < results .size(); i++) {
JSONObject item = results.getJSONObject(i);
String name = item.getString("name");
}