Question

我的代码在下面。 Android Studio中出现错误。有人请帮助我。我的PHP代码可以，但是为什么会出现此错误？

Register.java

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

public class Register extends AppCompatActivity {
    EditText et_name, et_number;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_register);

        et_name = (EditText) findViewById(R.id.nametxt);
        et_number = (EditText) findViewById(R.id.numbertxt);

    }

    public void userReg(View view){

        String names = et_name.getText().toString();
        String numbers = et_number.getText().toString();

        String method = "register";
        BackgroundTask backgroundTask = new BackgroundTask(this);
        backgroundTask.execute(method,names,numbers);
        finish();


    }
}

我的Background.java代码为

import android.content.Context;
import android.net.Uri;
import android.os.AsyncTask;
import android.widget.Toast;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;

import javax.net.ssl.HttpsURLConnection;

public class BackgroundTask extends AsyncTask<String,Void,String> {

    Context ctx;

    BackgroundTask(Context ctx){

        this.ctx = ctx;

    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... params) {
        String reg_url = "http://192.168.1.2/logins/register.php";
        String method = params[0];
        if(method.equals("register")){

            String name = params[1];
            String number = params[2];
            try {
                URL url = new URL(reg_url);
                HttpsURLConnection httpsURLConnection = (HttpsURLConnection) url.openConnection();
                httpsURLConnection.setRequestMethod("POST");
                httpsURLConnection.setDoOutput(true);
                OutputStream os = httpsURLConnection.getOutputStream();
                BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(os,"UTF-8"));
                String data = URLEncoder.encode("names","UTF-8")+"="+URLEncoder.encode(name,"UTF-8")+"&"
                        +URLEncoder.encode("numbers","UTF-8")+"="+URLEncoder.encode(number,"UTF-8");
                bufferedWriter.write(data);
                bufferedWriter.flush();
                bufferedWriter.close();
                os.close();
                InputStream IS = httpsURLConnection.getInputStream();
                IS.close();
                return "Registration Success...";
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }


        }

        return null;
    }

    @Override
    protected void onProgressUpdate(Void... values) {
        super.onProgressUpdate(values);
    }

    @Override
    protected void onPostExecute(String result) {
        Toast.makeText(ctx,result,Toast.LENGTH_LONG).show();
    }
}

我的Androidmainfest.xml是

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />

Android Studio错误为：

E / AndroidRuntime：致命异常：AsyncTask＃1 进程：com.example.smtanverhossain.myphpmysqlapplication，PID：5445 java.lang.RuntimeException：执行doInBackground（）时发生错误在android.os.AsyncTask $ 3.done（AsyncTask.java:300）在java.util.concurrent.FutureTask.finishCompletion（FutureTask.java:355）在java.util.concurrent.FutureTask.setException（FutureTask.java:222）在java.util.concurrent.FutureTask.run（FutureTask.java:242）在android.os.AsyncTask $ SerialExecutor $ 1.run（AsyncTask.java:231）在java.util.concurrent.ThreadPoolExecutor.runWorker（ThreadPoolExecutor.java:1112）在java.util.concurrent.ThreadPoolExecutor $ Worker.run（ThreadPoolExecutor.java:587）在java.lang.Thread.run（Thread.java:818）造成原因：java.lang.ClassCastException：com.android.okhttp.internal.http.HttpURLConnectionImpl无法强制转换到javax.net.ssl.HttpsURLConnection 在com.example.smtanverhossain.myphpmysqlapplication.BackgroundTask.doInBackground（BackgroundTask.java:46）在com.example.smtanverhossain.myphpmysqlapplication.BackgroundTask.doInBackground（BackgroundTask.java:19）在android.os.AsyncTask $ 2.call（AsyncTask.java:288）在java.util.concurrent.FutureTask.run（FutureTask.java:237）在android.os.AsyncTask $ SerialExecutor $ 1.run（AsyncTask.java:231）在java.util.concurrent.ThreadPoolExecutor.runWorker（ThreadPoolExecutor.java:1112）在java.util.concurrent.ThreadPoolExecutor $ Worker.run（ThreadPoolExecutor.java:587）在java.lang.Thread.run（Thread.java:818）

Answer 1

错误在日志中说明：Caused by: java.lang.ClassCastException: com.android.okhttp.internal.http.HttpURLConnectionImpl cannot be cast to javax.net.ssl.HttpsURLConnection

这意味着您不能在此行强制转换为HttpsURLConnection：

HttpsURLConnection httpsURLConnection = (HttpsURLConnection) url.openConnection();

这样做的原因是因为您的URL使用HTTP而不是HTTPS。当您用url.openConnection()调用HTTP时，它返回一个HttpURLConnection，并且同样适用于HTTPS。 documentation中对此进行了说明。

解决方案应该是将所有HttpsURLConnection替换为HttpURLConnection，并删除对HttpsURLConnection的转换。

Answer 2

@Tohu的解决方案可能会解决您的转换错误，这是我想带给您的，您正在将活动上下文传递给asynktask，而您要通过调用finish()来销毁这个任务，这在显示带有活动上下文的吐司时可能会给您一个错误。因此，请确保您提供有效的上下文，例如：-。

getApplicationContext()

E / AndroidRuntime：致命异常：Android的AsyncTask＃1错误

2 个答案: