Php 错误,我的应用程序每次将数据从应用程序传输到数据库时停止,反之亦然
这是我的一些代码。日志中的错误。提前谢谢 错误: 原因:java.lang.nullpointerexception:尝试对空对象引用调用虚拟方法“java.lang.string.org.json.jsonobject.tostring()” Login.javaPhp 错误,我的应用程序每次将数据从应用程序传输到数据库时停止,反之亦然,php,android,Php,Android,这是我的一些代码。日志中的错误。提前谢谢 错误: 原因:java.lang.nullpointerexception:尝试对空对象引用调用虚拟方法“java.lang.string.org.json.jsonobject.tostring()” Login.java public class Login extends Activity implements OnClickListener { private EditText user, pass; private Button mSubmi
public class Login extends Activity implements OnClickListener {
private EditText user, pass;
private Button mSubmit, mRegister;
private ProgressDialog pDialog;
JSONParser jsonParser = new JSONParser();
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.login);
// setup input fields
user = (EditText) findViewById(R.id.username);
pass = (EditText) findViewById(R.id.password);
// setup buttons
mSubmit = (Button) findViewById(R.id.login);
mRegister = (Button) findViewById(R.id.register);
// register listeners
mSubmit.setOnClickListener(this);
mRegister.setOnClickListener(this);
}
@Override
public void onClick(View v) {
int id = v.getId();
if (id == R.id.login) {
new AttemptLogin().execute();
} else if (id == R.id.register) {
Intent i = new Intent(this, Register.class);
startActivity(i);
} else {
}
}
class AttemptLogin extends AsyncTask<String, String, String> {
boolean failure = false;
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(Login.this);
pDialog.setMessage("Attempting login...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected String doInBackground(String... args) {
int success;
String username = user.getText().toString();
String password = pass.getText().toString();
try {
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("username", username));
params.add(new BasicNameValuePair("password", password));
Log.d("request!", "starting");
JSONObject json = jsonParser.makeHttpRequest(LOGIN_URL, "POST",
params);
Log.d("Login attempt", json.toString());
success = json.getInt(TAG_SUCCESS);
if (success == 1) {
Log.d("Login Successful!", json.toString());
SharedPreferences sp = PreferenceManager
.getDefaultSharedPreferences(Login.this);
Editor edit = sp.edit();
edit.putString("username", username);
edit.commit();
Intent i = new Intent(Login.this, ReadComments.class);
finish();
startActivity(i);
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;
}
protected void onPostExecute(String file_url) {
pDialog.dismiss();
if (file_url != null) {
Toast.makeText(Login.this, file_url, Toast.LENGTH_LONG).show();
}
}
}
公共类登录扩展活动实现OnClickListener{
私人编辑文本用户,通过;
私人按钮mSubmit,mRegister;
私人对话;
JSONParser JSONParser=新的JSONParser();
私有静态最终字符串标记_SUCCESS=“SUCCESS”;
私有静态最终字符串标记_MESSAGE=“MESSAGE”;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
//TODO自动生成的方法存根
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
//设置输入字段
user=(EditText)findViewById(R.id.username);
pass=(EditText)findViewById(R.id.password);
//设置按钮
mSubmit=(按钮)findviewbyd(R.id.login);
mRegister=(按钮)findviewbyd(R.id.register);
//注册侦听器
mSubmit.setOnClickListener(这个);
mRegister.setOnClickListener(此);
}
@凌驾
公共void onClick(视图v){
int id=v.getId();
if(id==R.id.login){
新建AttemptLogin().execute();
}else if(id==R.id.register){
意图i=新意图(这是Register.class);
星触觉(i);
}否则{
}
}
类AttemptLogin扩展了AsyncTask{
布尔失败=假;
@凌驾
受保护的void onPreExecute(){
super.onPreExecute();
pDialog=newprogressdialog(Login.this);
setMessage(“正在尝试登录…”);
pDialog.setUndeterminate(假);
pDialog.setCancelable(真);
pDialog.show();
}
@凌驾
受保护的字符串doInBackground(字符串…args){
成功;
字符串username=user.getText().toString();
字符串密码=pass.getText().toString();
试一试{
List params=new ArrayList();
添加(新的BasicNameValuePair(“用户名”,用户名));
添加(新的BasicNameValuePair(“密码”,password));
Log.d(“请求!”,“启动”);
JSONObject json=jsonParser.makeHttpRequest(登录地址,“POST”,
参数);
Log.d(“登录尝试”,json.toString());
success=json.getInt(TAG_success);
如果(成功==1){
Log.d(“登录成功!”,json.toString();
SharedReferences sp=首选项管理器
.getDefaultSharedReferences(Login.this);
Editor edit=sp.edit();
edit.putString(“用户名”,用户名);
edit.commit();
意图i=新意图(Login.this、ReadComments.class);
完成();
星触觉(i);
返回json.getString(TAG_消息);
}否则{
Log.d(“登录失败!”,json.getString(TAG_MESSAGE));
返回json.getString(TAG_消息);
}
}捕获(JSONException e){
e、 printStackTrace();
}
返回null;
}
受保护的void onPostExecute(字符串文件\u url){
pDialog.disclose();
如果(文件url!=null){
Toast.makeText(Login.this,file_url,Toast.LENGTH_LONG.show();
}
}
}
}
Register.java
public class Register extends Activity implements OnClickListener{
private EditText user, pass;
private Button mRegister;
private ProgressDialog pDialog;
JSONParser jsonParser = new JSONParser();
private static final String TAG_SUCCESS = "success";
private static final String TAG_MESSAGE = "message";
@Override
protected void onCreate(Bundle savedInstanceState) {
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) {
new CreateUser().execute();
}
class CreateUser extends AsyncTask<String, String, String> {
@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) {
int success;
String username = user.getText().toString();
String password = pass.getText().toString();
try {
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("username", username));
params.add(new BasicNameValuePair("password", password));
Log.d("request!", "starting");
JSONObject json = jsonParser.makeHttpRequest(
REGISTER_URL, "POST", params);
Log.d("Registering attempt", json.toString());
success = json.getInt(TAG_SUCCESS);
if (success == 1) {
Log.d("User Created!", json.toString());
finish();
return json.getString(TAG_MESSAGE);
}else{
Log.d("Registering Failure!", json.getString(TAG_MESSAGE));
return json.getString(TAG_MESSAGE);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
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();
}
}
}
公共类寄存器扩展活动实现OnClickListener{
私人编辑文本用户,通过;
私人按钮注册器;
私人对话;
JSONParser JSONParser=新的JSONParser();
私有静态最终字符串标记_SUCCESS=“SUCCESS”;
私有静态最终字符串标记_MESSAGE=“MESSAGE”;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.register);
user=(EditText)findViewById(R.id.username);
pass=(EditText)findViewById(R.id.password);
mRegister=(按钮)findviewbyd(R.id.register);
mRegister.setOnClickListener(此);
}
@凌驾
公共void onClick(视图v){
新建CreateUser().execute();
}
类CreateUser扩展异步任务{
@凌驾
受保护的void onPreExecute(){
super.onPreExecute();
pDialog=新建进度对话框(Register.this);
setMessage(“正在创建用户…”);
pDialog.setUndeterminate(假);
pDialog.setCancelable(真);
pDialog.show();
}
@凌驾
受保护的字符串doInBackground(字符串…args){
成功;
字符串username=user.getText().toString();
字符串密码=pass.getText().toString();
试一试{
List params=new ArrayList();
添加(新的BasicNameValuePair(“用户名”,用户名));
添加(新的BasicNameValuePair(“密码”,password));
Log.d(“请求!”,“启动”);
JSONObject json=jsonParser.makeHttpRequest(
注册URL,“POST”,参数);
Log.d(“注册尝试”,json.toString());
success=json.getInt(TAG_success);
如果(成功==1){
Log.d(“用户创建的!”,json.toString());
完成();
返回json.getString(TAG_消息);
}否则{
Log.d(“注册失败!”,json.getString(TAG_MESSAGE));
返回json.getString(TAG_消息);
}
}捕获(JSONException e){
e、 printStackTrace();
}
返回null;
}
受保护的void onPostExecute(字符串文件\u url){
//删除产品后关闭对话框
pDialog.disclose();
如果(文件url!=null){
Toast.makeText(Register.this,file_url,Toast.LENGTH_LONG.show();
}
}
}
}
JSONParser.java
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
public JSONParser() {
}
public JSONObject getJSONFromUrl(final String url) {
try {
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
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());
Log.e("log_tag", "Failed data was:\n" + json);
}
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
Log.e("log_tag", "Failed data was:\n" + json);
}
return jObj;
}
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params) {
try {
if(method == "POST"){
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"){
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());
Log.e("log_tag", "Failed data was:\n" + json);
}
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
Log.e("log_tag", "Failed data was:\n" + json);
}
return jObj;
}
公共类JSONParser{
静态输入
<?php
require("config.inc.php");
if (!empty($_POST)) {
$query = "
SELECT
id,
username,
password
FROM users
WHERE
username = :username
";
$query_params = array(
':username' => $_POST['username']
);
try {
$stmt = $db->prepare($query);
$result = $stmt->execute($query_params);
}
catch (PDOException $ex) {
$response["success"] = 0;
$response["message"] = "Database Error1. Please Try Again!";
die(json_encode($response));
}
$validated_info = false;
$row = $stmt->fetch();
if ($row) {
if ($_POST['password'] === $row['password']) {
$login_ok = true;
}
}
if ($login_ok) {
$response["success"] = 1;
$response["message"] = "Login successful!";
die(json_encode($response));
} else {
$response["success"] = 0;
$response["message"] = "Invalid Credentials!";
die(json_encode($response));
}
} else {
?>
<h1>Login</h1>
<form action="login.php" method="post">
Username:<br />
<input type="text" name="username" placeholder="username" />
<br /><br />
Password:<br />
<input type="password" name="password" placeholder="password" value="" />
<br /><br />
<input type="submit" value="Login" />
</form>
<a href="register.php">Register</a>
<?php
}
?>
require("config.inc.php");
if (!empty($_POST)) {
if (empty($_POST['username']) || empty($_POST['password'])) {
$response["success"] = 0;
$response["message"] = "Please Enter Both a Username and Password.";
die(json_encode($response));
}
$query = " SELECT 1 FROM users WHERE username = :user";
$query_params = array(
':user' => $_POST['username']
);
try {
$stmt = $db->prepare($query);
$result = $stmt->execute($query_params);
}
catch (PDOException $ex) {
$response["success"] = 0;
$response["message"] = "Database Error1. Please Try Again!";
die(json_encode($response));
}
$row = $stmt->fetch();
if ($row) {
$response["success"] = 0;
$response["message"] = "I'm sorry, this username is already in use";
die(json_encode($response));
}
$query = "INSERT INTO users ( username, password ) VALUES ( :user, :pass ) ";
$query_params = array(
':user' => $_POST['username'],
':pass' => $_POST['password']
);
try {
$stmt = $db->prepare($query);
$result = $stmt->execute($query_params);
}
catch (PDOException $ex) {
$response["success"] = 0;
$response["message"] = "Database Error2. Please Try Again!";
die(json_encode($response));
}
$response["success"] = 1;
$response["message"] = "Username Successfully Added!";
echo json_encode($response);
} 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
}
?>