我尝试了一个关于从Android将数据插入mysql的互联网教程
在activity_main.xml中，有一个注册新用户的按钮
所以我把所有的信息，如名字等等。
当用户点击提交按钮时，它应该重定向回activity_main.xml。
但是，当我单击提交时，应用程序被强制关闭，并且数据未插入到mysql数据库中。
我的问题是，代码究竟出了什么问题？
请给我建议。
代码中的所有内容都与我用于Android应用程序的内容相同。此外，我在这里提供日志跟踪。
任何帮助表示赞赏...
regactivity.java
package com.example.estate;
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.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class RegActivity extends Activity {
// Progress Dialog
private ProgressDialog pDialog;
JSONParser jsonParser = new JSONParser();
EditText fname;
EditText lname;
EditText username;
EditText password;
EditText location;
EditText contact;
Button btnreg;
Button btncancel;
// url to create new product
private static String url_new_user = "http://192.168.43.236/Estate_Conny/new_user.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.reg_activity);
// Edit Text
fname = (EditText) findViewById(R.id.fname);
lname = (EditText) findViewById(R.id.lname);
username = (EditText) findViewById(R.id.uname);
password = (EditText) findViewById(R.id.pass);
location = (EditText) findViewById(R.id.addr);
contact = (EditText) findViewById(R.id.contact);
// Create button
btnreg = (Button) findViewById(R.id.btnreg);
btncancel = (Button) findViewById(R.id.btncancel);
// button click event
btnreg.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// creating new product in background thread
new CreateNewProduct().execute();
}
});
btncancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
finish();
Intent i = new Intent(getApplicationContext(), MainActivity.class);
startActivity(i);
}
});
}
/**
* Background Async Task to Create new product
* */
class CreateNewProduct extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(RegActivity.this);
pDialog.setMessage("Registering New User..");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
/**
* Creating product
* */
protected String doInBackground(String... args) {
String Firstname = fname.getText().toString();
String Lastname = lname.getText().toString();
String Username = username.getText().toString();
String Password = password.getText().toString();
String Address = location.getText().toString();
String Contact = contact.getText().toString();
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("fname", Firstname));
params.add(new BasicNameValuePair("lname", Lastname));
params.add(new BasicNameValuePair("username", Username));
params.add(new BasicNameValuePair("password", Password));
params.add(new BasicNameValuePair("location", Address));
params.add(new BasicNameValuePair("contact", Contact));
// getting JSON Object
// Note that create product url accepts POST method
JSONObject json = jsonParser.makeHttpRequest(url_new_user,
"POST", params);
// check log cat fro response
Log.d("Create Response", json.toString());
// check for success tag
try {
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// successfully created product
finish();
Intent i = new Intent(getApplicationContext(), MainActivity.class);
startActivity(i);
} else {
// failed to create product
}
} 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 done
pDialog.dismiss();
}
}
}
MainActivity.java
package com.example.estate;
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 com.example.estate.RegActivity;
//import com.example.androidhive.NewProductActivity;
import com.example.estate.R;
import com.example.estate.JSONParser;
import com.example.estate.MainActivity;
//import com.example.estate.ReadComments;
import com.example.estate.RegActivity;
//import com.example.estate.Login.AttemptLogin;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener{
Button btnlogin;
Button btnreg;
Button btncancel;
EditText username;
EditText password;
private ProgressDialog pDialog;
JSONParser jsonParser = new JSONParser();
private static final String LOGIN_URL = "http://192.168.43.101/Estate_Conny/login.php";
private static final String TAG_SUCCESS = "success";
private static final String TAG_MESSAGE = "message";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Buttons
btnlogin = (Button) findViewById(R.id.btnlogin );
btnreg = (Button) findViewById(R.id.btncreate);
btncancel = (Button) findViewById(R.id.btnquit);
username = (EditText) findViewById(R.id.inputname);
password = (EditText) findViewById(R.id.inputpassword);
btnreg.setOnClickListener(this);
btnlogin.setOnClickListener(this);
btncancel.setOnClickListener(this);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.btnlogin:
new AttemptLogin().execute();
break;
case R.id.btncreate:
Intent i = new Intent(this, RegActivity.class);
startActivity(i);
break;
case R.id.btnquit:
finish();
break;
default:
break;
}
}
class AttemptLogin extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
boolean failure = false;
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Logging in 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 user = username.getText().toString();
String pass = password.getText().toString();
try {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("username", user));
params.add(new BasicNameValuePair("password", pass));
Log.d("request!", "starting");
// getting product details by making HTTP request
JSONObject json = jsonParser.makeHttpRequest(
LOGIN_URL, "POST", params);
// check your log for json response
Log.d("Login attempt", json.toString());
// json success tag
success = json.getInt(TAG_SUCCESS);
if (success == 1) {
Log.d("Login Successful!", json.toString());
Intent i = new Intent(MainActivity.this, ScreenActivity.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;
}
/**
* 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(MainActivity.this, file_url, Toast.LENGTH_LONG).show();
}
}
}
}
new_user.php
<?php
/*
* Following code will create a new product row
* All product details are read from HTTP Post Request
*/
// array for JSON response
$response = array();
/ check for required fields
if (isset($_POST['fname']) && isset($_POST['lname']) && isset($_POST['username']) && isset($_POST['password']) && isset($_POST['location']) && isset($_POST['contact'])) {
$fname = $_POST['fname'];
$lname = $_POST['lname'];
$username = $_POST['username'];
$password = $_POST['password'];
$location = $_POST['location'];
$contact = $_POST['contact'];
// include db connect class
require_once __DIR__ . '/db_connect.php';
// connecting to db
$db = new DB_CONNECT();
// mysql inserting a new row
$result = mysql_query("INSERT INTO user(firstname, lastname, username, password, location, contact) VALUES('$fname', '$lname', '$username','$password','$location','$contact')");
// check if row inserted or not
if ($result) {
// successfully inserted into database
$response["success"] = 1;
$response["message"] = "User successfully Registered.";
// echoing JSON response
echo json_encode($response);
} else {
// failed to insert row
$response["success"] = 0;
$response["message"] = "Oops! An error occurred.";
// echoing JSON response
echo json_encode($response);
}
} else {
// required field is missing
$response["success"] = 0;
$response["message"] = "Required field(s) is missing";
// echoing JSON response
echo json_encode($response);
}
?>
Log_traces：
Process: agrawal.trial.server, PID: 21767
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.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
at android.os.Handler.<init>(Handler.java:200)
at android.os.Handler.<init>(Handler.java:114)
at android.widget.Toast$TN.<init>(Toast.java:345)
at android.widget.Toast.<init>(Toast.java:100)
at android.widget.Toast.makeText(Toast.java:256)
at agrawal.trial.server.RegActivity$CreateNewProduct.doInBackground(RegActivity.java:116)
at agrawal.trial.server.RegActivity$CreateNewProduct.doInBackground(RegActivity.java:89)
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)
java.lang.IllegalArgumentException: HTTP entity may not be null
at org.apache.http.util.EntityUtils.toString(EntityUtils.java:110)
at org.apache.http.util.EntityUtils.toString(EntityUtils.java:146)
at miui.util.ErrorReport.b(SourceFile:363)
at miui.util.ErrorReport.sendReportRequest(SourceFile:320)
at miui.util.ErrorReport$2.a(SourceFile:336)
at miui.util.ErrorReport$2.doInBackground(SourceFile:333)
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)
12-01 20:31:48.771 1057-1225/? W/ContextImpl﹕ Calling a method in the system process without a qualified user: android.app.ContextImpl.bindService:1585 android.content.ContextWrapper.bindService:517 miui.os.DropBoxManager.b:361 miui.os.DropBoxManager.a:350 miui.os.DropBoxManager.addText:314
12-01 20:31:48.801 1138-1150/? W/MessageQueue﹕ Handler (com.miui.internal.server.DropBoxManagerService$2) {428282d8} sending message to a Handler on a dead thread
答案 0 :(得分：1)
if (success == 1) {
// successfully created product
Intent i = new Intent(getApplicationContext(), MainActivity.class);
startActivity(i);
finish(); //replace position of This
} else {
// failed to create product
}
将此信息放入onpostExecute阻止从后方的Do中删除