我是Android的新手我想知道如何连接数据库。我看到你的视频中的一个视频，我跟着洞视频但它不工作。我不知道我哪里弄错了。请帮助我。从一周开始我正在尝试的话但是现在我也没有得到解决方案请帮我堆叠流量。
class ServerRequests {
ProgressDialog progressDialog;
public static final int CONNECTION_TIMEOUT=1000*15;
public static final String
SERVER_ADDRESS="http://192.168.1.11/myfolder/new1.php";
public ServerRequests(Context context){
progressDialog=new ProgressDialog(context);
progressDialog.setCancelable(false);
progressDialog.setTitle("processing");
progressDialog.setMessage("please wait.....");
}
public void storeUserDataInBackground(User user,GetUserCallbackuserCallback{
progressDialog.show();
new StoreUserDataAsyncTask(user,userCallback).execute();
}
public void fetchUserDataInBackground(User user,GetUserCallback callBack){
progressDialog.show();
new fetchUserDataAsynctask(user,callBack).execute();
}
public class StoreUserDataAsyncTask extends AsyncTask<Void,Void,Void>{
User user;
GetUserCallback userCallback;
public StoreUserDataAsyncTask(User user,GetUserCallback userCallback){
this.user=user;
this.userCallback=userCallback;
}
@Override
protected Void doInBackground(Void... params) {
ArrayList<NameValuePair>dataToSend=new ArrayList<>();
dataToSend.add(new BasicNameValuePair("name",user.name));
dataToSend.add(new BasicNameValuePair("age",user.age + ""));
dataToSend.add(new BasicNameValuePair("username",user.username));
dataToSend.add(new BasicNameValuePair("password",user.password));
HttpParams httpRequestParams = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpRequestParams,CONNECTION_TIMEOUT);
HttpConnectionParams.setSoTimeout(httpRequestParams,CONNECTION_TIMEOUT);
HttpClient client = new DefaultHttpClient(httpRequestParams);
HttpPost post = new HttpPost(SERVER_ADDRESS + "Register.php");
try{
post.setEntity(new URLEncoderFormEntity(dataToSend));
client.execute(post);
}catch (Exception e){
e.printStackTrace();
}
return null;
}
@Override
protected void onpostExecute(Void aVoid){
progressDialog.dismiss();
userCallback.done(null);
super.onPostExecute(aVoid);
}
}
public fetchUserDataAsyncTask extends AsyncTask<Void,Void,User>{
User user;
GetUserCallback userCallback;
public fetchUserDataAsyncTask(User user,GetUserCallback userCallback){
this.user=user;
this.userCallback = userCallback;
}
@Override
protected User doInBackground(Void... params){
ArrayList<NameValuePair>dataToSend=new ArrayList<>();
dataToSend.add(new BasicNameValuePair("username",user.username));
dataToSend.add(new BasicNameValuePair("password",user.password));
HttpParams httpRequestParams = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(httpRequestParams, CONNECTION_TIMEOUT);
HttpConnectionParams.setSoTimeout(httpRequestParams, CONNECTION_TIMEOUT);
HttpClient client = new DefaultHttpClient(httpRequestParams);
HttpPost post = new HttpPost(SERVER_ADDRESS + "FetchUserData.php");
User returnedUser=null;
try{
post.setEntity(new URLEncoderFormEntity(dataToSend));
HttpResponce httpResponce=client.execute(post);
HttpEntity entity=httpResponce.getEntity();
String result= EntityUtils.toString(entity);
JSONObject jObject=new JSONObject(result);
if (jObject.length()==0){
user=null;
}else{
String name=jObject.getString("name");
int age =jObject.getInt("age");
returnedUser=new User(name,age,user.username,user.password);
}
}catch (Exception e){
e.printStackTrace();
}
return returnedUser;
}
@Override
protected void onPostExecute(User returnedUser){
progressDialog.dismiss();
userCallback.done(null);
super.onPostExecute(returnedUser);
}
}
}
enter code here
public class LoginActivity extends AppCompatActivity implements View.OnClickListener {
Button blogin;
EditText etusername,etpassword;
TextView tvregister;
UserLocalStore userLocalStore;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
etusername=(EditText)findViewById(R.id.username_edit);
etpassword=(EditText)findViewById(R.id.password_edit);
blogin=(Button)findViewById(R.id.login_button);
tvregister=(TextView)findViewById(R.id.tv_register);
blogin.setOnClickListener(this);
tvregister.setOnClickListener(this);
userLocalStore=new UserLocalStore(this);
}
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.login_button:
String username=etusername.getText().toString();
String password=etpassword.getText().toString();
User user=new User(username,password);
authenticate(user);
userLocalStore.storeUserData(user);
userLocalStore.setUserLoggedIn(true);
break;
case R.id.tv_register:
startActivity(new Intent(this,RegisterActivity.class));
break;
}
}
private void authenticate(User user) {
ServerRequests serverRequests = new ServerRequests(this);
serverRequests.fetchUserDataInBackground(user, new GetUserCallback() {
@Override
public void done(User returnedUser) {
if (returnedUser == null) {
showErrorMessage();
}else {
logUserIn(returnedUser);
}
}
});
}
private void showErrorMessage() {
AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(LoginActivity.this);
dialogBuilder.setMessage("Incorrect user details");
dialogBuilder.setPositiveButton("ok", null);
dialogBuilder.show();
}
private void logUserIn(User returnedUser){
userLocalStore.storeUserData(returnedUser);
userLocalStore.setUserLoggedIn(true);
startActivity(new Intent(this,MainActivity.class));
}
}
答案 0 :(得分：-1)
以下是您可以参考从服务器获取数据的链接。
使用PHP创建Web服务 Click here
<?php
include("connect.php");
$result="";
//get data from users (name for user variable is p1 and p2
//here I am stroing this value to par1 and par2
//method i am using is GET
$par1=$_GET['p1'];
$par2=$_GET['p2'];
$eve = "select * from table where field1='$par1' and field2='$par2'";
$re = mysql_query($eve);
$response = array();
$posts = array();
while($rt = mysql_fetch_array($re))
{
$f1=$rt['field1'];
$f2=$rt['field2'];
break;
}
$posts[] = array('p1'=> $f1,'p2'=> $f2);
$response['posts'] = $posts;
echo stripslashes(json_encode( array('item' => $posts)));
?>
对于AsyncTask示例 Click here
import android.app.ProgressDialog;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
public class Login extends AppCompatActivity {
boolean remember;
private ProgressDialog pDialog;
public static final String PREFS_NAME = "Preference";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
((Button) findViewById(R.id.btnlogin)).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//Login Validation
try {
pDialog = new ProgressDialog(Login.this);
pDialog.setMessage("Verifying...");
pDialog.show();
LoginVerifyTask g = new LoginVerifyTask();
g.execute(((EditText) findViewById(R.id.mobile)).getText().toString(), ((EditText) findViewById(R.id.password)).getText().toString());
} catch (Exception e) {
Log.e("cs", "catch error");
}
}
});
((TextView) findViewById(R.id.newuserregistrationtxtview)).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(getApplicationContext(), Registration1.class);
startActivity(i);
}
});
}
public class LoginVerifyTask extends AsyncTask<String, Void, String>
{
String u,p;
void LoginActivity(String s)
{
}
@Override
protected void onPostExecute(String json) {
// TODO Auto-generated method stub
pDialog.dismiss();
pDialog = null;
if (json == null)
{
return;
}
String csv="";
try {
JSONObject js = new JSONObject(json);
JSONArray user = js.getJSONArray("item");
for(int i=0;i<user.length();i++)
{
JSONObject j2 = user.getJSONObject(i);
//received data
String result = j2.get("p1").toString();
break;
}
}
catch(JSONException js)
{
}
return;
}
@Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
u = params[0];
p = params[1];
String tempdata="";
String buffer="";
try
{
URL url = new URL("http://websitename.com/folder/webservice.php?p1=" + params[0].replace(" ", "%20") + "&p2=" + params[1].replace(" ", "%20"));
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.connect();
InputStream is = conn.getInputStream();
//buffer = new String();
if(is==null)
{
return tempdata;
}
else
{
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
String line="";
while( (line = reader.readLine())!=null)
{
buffer += line;
}
return buffer;
}
}
catch(Exception e)
{
Log.e("cs", e.toString());
}
return buffer;
}
}
}