我正在进行登录/注册活动。我使用MySQL和PHP作为我的数据库。
仅供参考，我对Android开发相对较新，所以请把它作为新手＆＃39;友好。谢谢！
我无法登录因为应用程序崩溃（抱歉，Amity已停止工作）。所以我检查注册活动，看它是否与数据库连接，我创建一个新用户名，输入密码，点击注册，然后出现相同的消息（抱歉，Amity已停止工作）。我通过phpmyadmin检查我的数据库表，新用户插入新行。
logcat错误：
08-14 06:06:56.332 1255-1269/com.amity.paul.amity E/JSON Parser﹕ Error parsing data org.json.JSONException: Value  of type java.lang.String cannot be converted to JSONObject
08-14 06:06:56.332 1255-1269/com.amity.paul.amity W/dalvikvm﹕ threadid=12: thread exiting with uncaught exception (group=0xb3adcba8)
08-14 06:06:56.382 1255-1269/com.amity.paul.amity E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #2
Process: com.amity.paul.amity, PID: 1255
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.NullPointerException
at com.amity.paul.amity.register$CreateUser.doInBackground(register.java:113)
at com.amity.paul.amity.register$CreateUser.doInBackground(register.java:76)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
08-14 06:06:56.812 1255-1255/com.amity.paul.amity I/Choreographer﹕ Skipped 62 frames! The application may be doing too much work on its main thread.
08-14 06:06:57.722 1255-1255/com.amity.paul.amity I/Choreographer﹕ Skipped 201 frames! The application may be doing too much work on its main thread.
08-14 06:06:58.102 1255-1255/com.amity.paul.amity I/Choreographer﹕ Skipped 63 frames! The application may be doing too much work on its main thread.
08-14 06:06:58.712 1255-1255/com.amity.paul.amity E/WindowManager﹕ android.view.WindowLeaked: Activity com.amity.paul.amity.register has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{b3d97bf8 V.E..... R.....ID 0,0-456,144} that was originally added here
at android.view.ViewRootImpl.<init>(ViewRootImpl.java:348)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:248)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
at android.app.Dialog.show(Dialog.java:286)
at com.amity.paul.amity.register$CreateUser.onPreExecute(register.java:90)
at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:587)
at android.os.AsyncTask.execute(AsyncTask.java:535)
at com.amity.paul.amity.register.onClick(register.java:72)
at android.view.View.performClick(View.java:4438)
at android.view.View$PerformClick.run(View.java:18422)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
register.php
<?php
/*
Our "config.inc.php" file connects to database every time we include or require
it within a php script. Since we want this script to add a new user to our db,
we will be talking with our database, and therefore,
let's require the connection to happen:
*/
require("config.inc.php");
//if posted data is not empty
if (!empty($_POST)) {
//If the username or password is empty when the user submits
//the form, the page will die.
//Using die isn't a very good practice, you may want to look into
//displaying an error message within the form instead.
//We could also do front-end form validation from within our Android App,
//but it is good to have a have the back-end code do a double check.
if (empty($_POST['username']) || empty($_POST['password'])) {
// Create some data that will be the JSON response
$response["success"] = 0;
$response["message"] = "Please Enter Both a Username and Password.";
//die will kill the page and not execute any code below, it will also
//display the parameter... in this case the JSON data our Android
//app will parse
die(json_encode($response));
}
//if the page hasn't died, we will check with our database to see if there is
//already a user with the username specificed in the form. ":user" is just
//a blank variable that we will change before we execute the query. We
//do it this way to increase security, and defend against sql injections
$query = " SELECT 1 FROM users WHERE username = :user";
//now lets update what :user should be
$query_params = array(
':user' => $_POST['username']
);
//Now let's make run the query:
try {
// These two statements run the query against your database table.
$stmt = $db->prepare($query);
$result = $stmt->execute($query_params);
}
catch (PDOException $ex) {
// For testing, you could use a die and message.
//die("Failed to run query: " . $ex->getMessage());
//or just use this use this one to product JSON data:
$response["success"] = 0;
$response["message"] = "Database Error1. Please Try Again!";
die(json_encode($response));
}
//fetch is an array of returned data. If any data is returned,
//we know that the username is already in use, so we murder our
//page
$row = $stmt->fetch();
if ($row) {
// For testing, you could use a die and message.
//die("This username is already in use");
//You could comment out the above die and use this one:
$response["success"] = 0;
$response["message"] = "I'm sorry, this username is already in use";
die(json_encode($response));
}
//If we have made it here without dying, then we are in the clear to
//create a new user. Let's setup our new query to create a user.
//Again, to protect against sql injects, user tokens such as :user and :pass
$query = "INSERT INTO users ( username, password ) VALUES ( :user, :pass ) ";
//Again, we need to update our tokens with the actual data:
$query_params = array(
':user' => $_POST['username'],
':pass' => $_POST['password']
);
//time to run our query, and create the user
try {
$stmt = $db->prepare($query);
$result = $stmt->execute($query_params);
}
catch (PDOException $ex) {
// For testing, you could use a die and message.
//die("Failed to run query: " . $ex->getMessage());
//or just use this use this one:
$response["success"] = 0;
$response["message"] = "Database Error2. Please Try Again!";
die(json_encode($response));
}
//If we have made it this far without dying, we have successfully added
//a new user to our database. We could do a few things here, such as
//redirect to the login page. Instead we are going to echo out some
//json data that will be read by the Android application, which will login
//the user (or redirect to a different activity, I'm not sure yet..)
$response["success"] = 1;
$response["message"] = "Username Successfully Added!";
echo json_encode($response);
//for a php webservice you could do a simple redirect and die.
//header("Location: login.php");
//die("Redirecting to login.php");
} else {
?>
<h1>Register</h1>
<form action="register.php" method="post">
Username:<br />
<input type="text" name="username" value="" />
<br /><br />
Password:<br />
<input type="password" name="password" value="" />
<br /><br />
<input type="submit" value="Register New User" />
</form>
<?php
}
?>
register.java
package com.amity.paul.amity;
/**
* Created by Paul on 13/08/2014.
*/
import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import library.JSONParser;
public class register extends Activity implements OnClickListener{
private EditText user, pass;
private Button mRegister;
// Progress Dialog
private ProgressDialog pDialog;
// JSON parser class
JSONParser jsonParser = new JSONParser();
//php login script
//localhost :
//testing on your device
//put your local ip instead, on windows, run CMD > ipconfig
//or in mac's terminal type ifconfig and look for the ip under en0 or en1
// private static final String LOGIN_URL = "http://xxx.xxx.x.x:1234/webservice/register.php";
//testing on Emulator:
private static final String LOGIN_URL = "http://192.168.2.157/amity/register.php";
//testing from a real server:
//private static final String LOGIN_URL = "http://www.yourdomain.com/webservice/register.php";
//ids
private static final String TAG_SUCCESS = "success";
private static final String TAG_MESSAGE = "message";
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.register);
user = (EditText)findViewById(R.id.username);
pass = (EditText)findViewById(R.id.password);
mRegister = (Button)findViewById(R.id.register);
mRegister.setOnClickListener(this);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
new CreateUser().execute();
}
class CreateUser extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
boolean failure = false;
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(register.this);
pDialog.setMessage("Creating User...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected String doInBackground(String... args) {
// TODO Auto-generated method stub
// Check for success tag
int success;
String username = user.getText().toString();
String password = pass.getText().toString();
try {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("username", username));
params.add(new BasicNameValuePair("password", password));
Log.d("request!", "starting");
//Posting user data to script
JSONObject json = jsonParser.makeHttpRequest(
LOGIN_URL, "POST", params);
// full json response
Log.d("Login attempt", json.toString());
// json success element
success = json.getInt(TAG_SUCCESS);
if (success == 1) {
Log.d("User Created!", json.toString());
finish();
return json.getString(TAG_MESSAGE);
}else{
Log.d("Login Failure!", json.getString(TAG_MESSAGE));
return json.getString(TAG_MESSAGE);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog once product deleted
pDialog.dismiss();
if (file_url != null){
Toast.makeText(register.this, file_url, Toast.LENGTH_LONG).show();
}
}
}
}
register.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Username"
android:layout_below="@+id/textView2"
android:layout_alignLeft="@+id/password"
android:layout_alignStart="@+id/password"
android:layout_marginTop="86dp" />
<EditText
android:id="@+id/username"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/textView1"
android:layout_below="@+id/textView1"
android:ems="10" />
<TextView
android:id="@+id/TextView01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/username"
android:layout_below="@+id/username"
android:text="Password" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:text="Android Remote Server Tutorial"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textStyle="bold"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
<EditText
android:id="@+id/password"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/TextView01"
android:layout_centerHorizontal="true"
android:ems="10"
android:inputType="textPassword" />
<Button
android:id="@+id/register"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="@+id/password"
android:layout_below="@+id/password"
android:text="Register" />
</RelativeLayout>
JSONParser.java
package library;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(final String url) {
// Making HTTP request
try {
// Construct the client and the HTTP request.
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
// Execute the POST request and store the response locally.
HttpResponse httpResponse = httpClient.execute(httpPost);
// Extract data from the response.
HttpEntity httpEntity = httpResponse.getEntity();
// Open an inputStream with the data content.
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
// Create a BufferedReader to parse through the inputStream.
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
// Declare a string builder to help with the parsing.
StringBuilder sb = new StringBuilder();
// Declare a string to store the JSON object data in string form.
String line = null;
// Build the string until null.
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
// Close the input stream.
is.close();
// Convert the string builder data to an actual string.
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// Try to parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// Return the JSON Object.
return jObj;
}
// function get json from url
// by making HTTP POST or GET mehtod
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params) {
// Making HTTP request
try {
// check for request method
if(method == "POST"){
// request method is POST
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}else if(method == "GET"){
// request method is GET
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(params, "utf-8");
url += "?" + paramString;
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}