[英]Android connecting on MySQL using PHP
我試圖做我的第一個與MySQL上的連接的android應用程序,我谷歌很多,找到一些教程和類似的東西。 基於它們,我有以下代碼:
package com.example.helloworld;
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.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends Activity {
String name;
String id;
InputStream is=null;
String result=null;
String line=null;
int code;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final EditText e_id=(EditText) findViewById(R.id.editText1);
final EditText e_name=(EditText) findViewById(R.id.editText2);
Button insert=(Button) findViewById(R.id.button1);
insert.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
id = e_id.getText().toString();
name = e_name.getText().toString();
insert();
}
});
}
public void insert()
{
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("id",id));
nameValuePairs.add(new BasicNameValuePair("name",name));
try
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://localhost/xampp/android_connect/index.php");
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
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());
Toast.makeText(getApplicationContext(), "Invalid IP Address",
Toast.LENGTH_LONG).show();
}
try
{
BufferedReader reader = new BufferedReader
(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null)
{
sb.append(line + "\n");
}
is.close();
result = sb.toString();
Log.e("pass 2", "connection success ");
}
catch(Exception e)
{
Log.e("Fail 2", e.toString());
}
try
{
JSONObject json_data = new JSONObject(result);
code=(json_data.getInt("code"));
if(code==1)
{
Toast.makeText(getBaseContext(), "Inserted Successfully",
Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(getBaseContext(), "Sorry, Try Again",
Toast.LENGTH_LONG).show();
}
}
catch(Exception e)
{
Log.e("Fail 3", e.toString());
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
我看不到任何錯誤或任何東西,但是當我嘗試加載它時,它說:“無效的IP地址”(這是catch {}的錯誤消息)。 我嘗試研究哪里可能有問題,在LogCat中我發現此錯誤:
11-16 10:39:10.036: I/ActivityManager(150): Start proc com.example.helloworld for activity com.example.helloworld/.MainActivity: pid=612 uid=10045 gids={3003, 1028}
11-16 10:39:10.386: E/Trace(612): error opening trace file: No such file or directory (2)
11-16 10:39:10.966: D/gralloc_goldfish(612): Emulator without GPU emulation detected.
11-16 10:39:11.016: I/ActivityManager(150): Displayed com.example.helloworld/.MainActivity: +1s32ms
11-16 10:39:11.066: I/Choreographer(150): Skipped 34 frames! The application may be doing too much work on its main thread.
11-16 10:39:18.945: E/Fail 1(612): android.os.NetworkOnMainThreadException
11-16 10:39:18.975: E/Fail 2(612): java.lang.NullPointerException
11-16 10:39:18.975: E/Fail 3(612): java.lang.NullPointerException
11-16 10:39:19.195: D/dalvikvm(612): GC_CONCURRENT freed 191K, 4% free 6229K/6471K, paused 17ms+65ms, total 206ms
11-16 10:39:20.065: E/Fail 1(612): android.os.NetworkOnMainThreadException
11-16 10:39:20.075: E/Fail 2(612): java.lang.NullPointerException
11-16 10:39:20.075: E/Fail 3(612): java.lang.NullPointerException
11-16 10:39:20.645: E/Fail 1(612): android.os.NetworkOnMainThreadException
11-16 10:39:20.645: E/Fail 2(612): java.lang.NullPointerException
11-16 10:39:20.645: E/Fail 3(612): java.lang.NullPointerException
11-16 10:39:21.055: E/Fail 1(612): android.os.NetworkOnMainThreadException
11-16 10:39:21.065: E/Fail 2(612): java.lang.NullPointerException
11-16 10:39:21.065: E/Fail 3(612): java.lang.NullPointerException
11-16 10:39:21.535: E/Fail 1(612): android.os.NetworkOnMainThreadException
11-16 10:39:21.545: E/Fail 2(612): java.lang.NullPointerException
11-16 10:39:21.545: E/Fail 3(612): java.lang.NullPointerException
11-16 10:39:21.728: E/Fail 1(612): android.os.NetworkOnMainThreadException
11-16 10:39:21.735: E/Fail 2(612): java.lang.NullPointerException
11-16 10:39:21.735: E/Fail 3(612): java.lang.NullPointerException
11-16 10:39:21.925: E/Fail 1(612): android.os.NetworkOnMainThreadException
11-16 10:39:21.925: E/Fail 2(612): java.lang.NullPointerException
11-16 10:39:21.925: E/Fail 3(612): java.lang.NullPointerException
11-16 10:39:22.535: I/Choreographer(612): Skipped 37 frames! The application may be doing too much work on its main thread.
: E/(): Device disconnected: 1
: E/(): Device disconnected
尤其是我看找不到目錄,我嘗試在瀏覽器中打開相同的地址,並且我沒有問題地打開它。 有人可以告訴我我在做什么錯嗎?
謝謝
localhost
指向設備本身; 因此,您可以嘗試以下操作:
如果出於測試目的在自己的網絡上運行此程序,請嘗試鍵入本地ip而不是localhost
, 例如 http://192.168.0.123
嘗試使用http://10.0.2.2
而不是localhost
,在設備上的瀏覽器中鍵入它,然后查看其是否正確連接。
還要檢查這個問題 。
NetworkOnMainThreadException
您正在嘗試在應用程序的主線程上進行網絡操作,這可能會導致嚴重的延遲和不可預測的結果 。
您應該始終使用AsyncTask
進行網絡操作。 請參閱android docs中的這篇文章 。
這是一個示例用法;
您的AsyncTask
應該如下所示:
private class DownloadWebpageTask extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
// params comes from the execute() call: params[0] is the url.
try {
// Initialize your parameters
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("id",urls[1]));
nameValuePairs.add(new BasicNameValuePair("name",urls[2]));
// Make your HTTP Request
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(urls[0]);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
// Read the response
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
// Return the response.
return result;
} catch (IOException e) {
return "Unable to retrieve web page. URL may be invalid.";
}
}
// onPostExecute gets the results of the AsyncTask.
@Override
protected void onPostExecute(String result) {
// Read your response into a JSONObject and do stuff...
JSONObject json_data = new JSONObject(result);
code=(json_data.getInt("code"));
if(code==1)
{
Toast.makeText(getBaseContext(), "Inserted Successfully", Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(getBaseContext(), "Sorry, Try Again", Toast.LENGTH_LONG).show();
}
}
}
您可以像這樣使用它:
// Params : url, id, name
new DownloadWebpageTask().execute("http://10.0.2.2/xampp/android_connect/index.php", "12345", "Foo Bar");
這是一個完整的示例,您的代碼應如下所示:
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.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends Activity {
String name;
String id;
InputStream is=null;
String result=null;
String line=null;
int code;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final EditText e_id=(EditText) findViewById(R.id.editText1);
final EditText e_name=(EditText) findViewById(R.id.editText2);
Button insert=(Button) findViewById(R.id.button1);
insert.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
id = e_id.getText().toString();
name = e_name.getText().toString();
insert();
}
});
}
public void insert()
{
new DownloadWebpageTask().execute("http://10.0.2.2/xampp/android_connect/index.php", id, name);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
private class DownloadWebpageTask extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
// params comes from the execute() call: params[0] is the url.
try {
// Initialize your parameters
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("id",urls[1]));
nameValuePairs.add(new BasicNameValuePair("name",urls[2]));
// Make your HTTP Request
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(urls[0]);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
// Read the response
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
// Return the response.
return result;
} catch (IOException e) {
return "Unable to retrieve web page. URL may be invalid.";
}
}
// onPostExecute gets the results of the AsyncTask.
@Override
protected void onPostExecute(String result) {
// Read your response into a JSONObject and do stuff...
JSONObject json_data = new JSONObject(result);
code=(json_data.getInt("code"));
if(code==1)
{
Toast.makeText(getBaseContext(), "Inserted Successfully", Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(getBaseContext(), "Sorry, Try Again", Toast.LENGTH_LONG).show();
}
}
}
}
我認為您有兩個問題:
localhost
更改為計算機的IP地址 。 AsyncTask
或使用像Retrofit這樣的庫! ;) 你做錯了。 嘗試10.0.2.2/android_connect/index.php。 10.0.2.2重定向到您的xampp / htdoc /文件夾。
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