我需要使用xampp.So连接并测试我的应用程序，我引用此http://www.androidhive.info/2012/05/how-to-connect-android-with-php-mysql/tutorial。最后我收到了一个logcat错误。
我不知道如何解决这个问题。对于添加产品我只需要这样做。所以我将该链接更改为本地主机。
我在下面的代码中指出了错误行。
堆栈跟踪：
10-21 02:40:54.739: E/Buffer Error(2680): Error converting result java.lang.NullPointerException: lock == null
10-21 02:40:54.739: E/JSON Parser(2680): Error parsing data org.json.JSONException: End of input at character 0 of
10-21 02:40:54.739: W/dalvikvm(2680): threadid=12: thread exiting with uncaught exception (group=0xb3a9fba8)
10-21 02:40:54.849: E/AndroidRuntime(2680): FATAL EXCEPTION: AsyncTask #2
10-21 02:40:54.849: E/AndroidRuntime(2680): Process: com.steve.test, PID: 2680
10-21 02:40:54.849: E/AndroidRuntime(2680): java.lang.RuntimeException: An error occured while executing doInBackground()
10-21 02:40:54.849: E/AndroidRuntime(2680): at android.os.AsyncTask$3.done(AsyncTask.java:300)
10-21 02:40:54.849: E/AndroidRuntime(2680): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
10-21 02:40:54.849: E/AndroidRuntime(2680): at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
10-21 02:40:54.849: E/AndroidRuntime(2680): at java.util.concurrent.FutureTask.run(FutureTask.java:242)
10-21 02:40:54.849: E/AndroidRuntime(2680): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
10-21 02:40:54.849: E/AndroidRuntime(2680): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
10-21 02:40:54.849: E/AndroidRuntime(2680): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
10-21 02:40:54.849: E/AndroidRuntime(2680): at java.lang.Thread.run(Thread.java:841)
10-21 02:40:54.849: E/AndroidRuntime(2680): Caused by: java.lang.NullPointerException
10-21 02:40:54.849: E/AndroidRuntime(2680): at com.steve.test.NewProductActivity$CreateNewProduct.doInBackground(NewProductActivity.java:99)
10-21 02:40:54.849: E/AndroidRuntime(2680): at com.steve.test.NewProductActivity$CreateNewProduct.doInBackground(NewProductActivity.java:1)
10-21 02:40:54.849: E/AndroidRuntime(2680): at android.os.AsyncTask$2.call(AsyncTask.java:288)
10-21 02:40:54.849: E/AndroidRuntime(2680): at java.util.concurrent.FutureTask.run(FutureTask.java:237)
10-21 02:40:54.849: E/AndroidRuntime(2680): ... 4 more
10-21 02:40:55.679: I/Choreographer(2680): Skipped 98 frames! The application may be doing too much work on its main thread.
10-21 02:40:56.419: I/Choreographer(2680): Skipped 167 frames! The application may be doing too much work on its main thread.
10-21 02:40:56.599: I/Choreographer(2680): Skipped 46 frames! The application may be doing too much work on its main thread.
10-21 02:40:56.849: I/Choreographer(2680): Skipped 62 frames! The application may be doing too much work on its main thread.
10-21 02:40:57.819: D/dalvikvm(2680): GC_FOR_ALLOC freed 210K, 7% free 4050K/4336K, paused 196ms, total 207ms
10-21 02:40:57.819: E/WindowManager(2680): android.view.WindowLeaked: Activity com.steve.test.NewProductActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{b3db5a78 V.E..... R.....ID 0,0-329,175} that was originally added here
10-21 02:40:57.819: E/WindowManager(2680): at android.view.ViewRootImpl.<init>(ViewRootImpl.java:348)
10-21 02:40:57.819: E/WindowManager(2680): at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:248)
10-21 02:40:57.819: E/WindowManager(2680): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
10-21 02:40:57.819: E/WindowManager(2680): at android.app.Dialog.show(Dialog.java:286)
10-21 02:40:57.819: E/WindowManager(2680): at com.steve.test.NewProductActivity$CreateNewProduct.onPreExecute(NewProductActivity.java:76)
10-21 02:40:57.819: E/WindowManager(2680): at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:587)
10-21 02:40:57.819: E/WindowManager(2680): at android.os.AsyncTask.execute(AsyncTask.java:535)
10-21 02:40:57.819: E/WindowManager(2680): at com.steve.test.NewProductActivity$1.onClick(NewProductActivity.java:56)
10-21 02:40:57.819: E/WindowManager(2680): at android.view.View.performClick(View.java:4438)
10-21 02:40:57.819: E/WindowManager(2680): at android.view.View$PerformClick.run(View.java:18422)
10-21 02:40:57.819: E/WindowManager(2680): at android.os.Handler.handleCallback(Handler.java:733)
10-21 02:40:57.819: E/WindowManager(2680): at android.os.Handler.dispatchMessage(Handler.java:95)
10-21 02:40:57.819: E/WindowManager(2680): at android.os.Looper.loop(Looper.java:136)
10-21 02:40:57.819: E/WindowManager(2680): at android.app.ActivityThread.main(ActivityThread.java:5017)
10-21 02:40:57.819: E/WindowManager(2680): at java.lang.reflect.Method.invokeNative(Native Method)
10-21 02:40:57.819: E/WindowManager(2680): at java.lang.reflect.Method.invoke(Method.java:515)
10-21 02:40:57.819: E/WindowManager(2680): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
10-21 02:40:57.819: E/WindowManager(2680): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
10-21 02:40:57.819: E/WindowManager(2680): at dalvik.system.NativeStart.main(Native Method)
NewProductActivity.java：
package com.example.test; ------>1st line
public class NewProductActivity extends Activity {
// Progress Dialog
private ProgressDialog pDialog;
JSONParser jsonParser = new JSONParser();
EditText inputName;
EditText inputPrice;
EditText inputDesc;
// url to create new product
private static String url_create_product = "http://localhost/android_connect/create_product.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.add_product);
// Edit Text
inputName = (EditText) findViewById(R.id.inputName);
inputPrice = (EditText) findViewById(R.id.inputPrice);
inputDesc = (EditText) findViewById(R.id.inputDesc);
// Create button
Button btnCreateProduct = (Button) findViewById(R.id.btnCreateProduct);
// button click event
btnCreateProduct.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// creating new product in background thread
new CreateNewProduct().execute(); --------->56th line
}
});
}
/**
* 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(NewProductActivity.this);
pDialog.setMessage("Creating Product..");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show(); ------->76th line
}
/**
* Creating product
* */
protected String doInBackground(String... args) {
String name = inputName.getText().toString();
String price = inputPrice.getText().toString();
String description = inputDesc.getText().toString();
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("name", name));
params.add(new BasicNameValuePair("price", price));
params.add(new BasicNameValuePair("description", description));
// getting JSON Object
// Note that create product url accepts POST method
JSONObject json = jsonParser.makeHttpRequest(url_create_product,
"POST", params);
// check log cat for response
Log.d("Create Response", json.toString()); ----->99th line
// check for success tag
try {
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// successfully created product
Intent i = new Intent(getApplicationContext(), AllProductsActivity.class);
startActivity(i);
// closing this screen
finish();
} 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();
}
}
}
JsonParser.class：
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
// 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.equals( "POST")){
Log.d("Steve Response",method);
// 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.equals("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;
}
}
清单：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.test"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainScreenActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.test.NewProductActivity" />
<activity android:name="com.example.test.EditProductActivity" />
<activity android:name="com.example.test.AllProductsActivity" />
</application>
</manifest>
答案 0 :(得分：4)
您可以在网址中提供IP而非本地主机。
192.xxx.xx.xxx:80
例如 - “http://192.xxx.xx.xxx:80/android_connect/create_product.php”
这里80是端口号。
您收到LogCat错误是因为URL没有响应或者重新获取任何JSONObject，因此会出现问题。
还要确保'create_product.php'给出正确的答案。
最好在问题中添加php代码。
希望有所帮助
答案 1 :(得分：2)
将您的localhost更改为IP地址。
private static String url_create_product = "http://127.0.0.1/android_connect/create_product.php";