java - 无法执行 Activity 的方法？

Question

您好，感谢您的提前帮助。我试图在我的 android 上读取一个文件，并在按下按钮时将其放入 ArrayList 中，但是我收到标题中的错误，并将在下面发布确切的代码。

MainActivity.Java

package com.teamfara.circadianrhythmmonitor2;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothServerSocket;
import android.bluetooth.BluetoothSocket;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Scanner;
import java.util.Set;
import java.util.UUID;

public class MainActivity extends AppCompatActivity {


    /* MAIN GOALS

      - Receive bodyTemp txt file and convert into array
      - Send light info as txt file
      - put bodyTemp into current graph
      - make targeted body temp graph
     */

    private final static int REQUEST_ENABLE_BT = 1;
    UUID myUUID = UUID.randomUUID();
    private static final int DISCOVER_DURATION = 300;
    private static final int REQUEST_BLU = 1;
    ArrayAdapter<String> mArrayAdapter;
    BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

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


        BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        if (!mBluetoothAdapter.isEnabled()) {
            Intent enableBIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableBIntent, REQUEST_ENABLE_BT);
        }

        //If there are paired devices
        /*Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
        if (pairedDevices.size() > 0) {
            //Loop through the paired devices
            for (BluetoothDevice device : pairedDevices) {
                //add the name and address to an array adapter to show in a ListView
                mArrayAdapter.add(device.getName() + "\n" + device.getAddress());
            }
        }
        */

        IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        registerReceiver(mReceiver, filter); // Don't forget to unregister during onDestroy

        Intent discoverableIntent = new
                Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
        discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
        startActivity(discoverableIntent);

    }

    public void receiveBodyTempInfo(View view) throws FileNotFoundException{

        ArrayList<Double> list = new ArrayList<>();

        File sdcard = Environment.getExternalStorageDirectory();

//Get the text file


//Read text from file
        Scanner file2 = new Scanner(new File(sdcard, "temp.txt"));

        while(file2.hasNextLine()) {
            String line = file2.nextLine();

            Scanner scanner = new Scanner(line);
            scanner.useDelimiter(",");
            while(scanner.hasNextDouble()) {
                list.add(scanner.nextDouble());
            }
            scanner.close();
        }


    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:src = "@drawable/flight2"
        android:scaleType = "centerCrop"
        />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation = "vertical"
        android:padding = "16sp"
        >

        <!-- Top three buttons-->
        <LinearLayout
            android:orientation = "horizontal"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1">

            <!-- Light-->
            <ImageView
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:src = "@drawable/light2"
                android:paddingBottom = "8sp"
                />

            <!-- Body Temp-->
            <ImageView
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:src = "@drawable/temperature"
                android:paddingBottom = "8sp"/>

            <!-- Heart Rate-->
            <ImageView
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:src = "@drawable/heart"/>

        </LinearLayout>


        <!-- Current Trip-->
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight = "1"
            android:orientation = "vertical"
            android:background="#CC0099FF"
            >

            <!-- Exact Trip-->
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="0dp"
                android:layout_weight="2"
                android:text = "New York -> London"
                android:textAllCaps = "true"
                android:textSize = "24sp"
                android:layout_gravity = "center_horizontal"
                />

            <!-- Be Awake...-->
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:text = "Wake up at "
                android:layout_gravity = "left"/>

            <!-- Be in Light...
            <TextView

                android:layout_width="wrap_content"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:text = "Be in Light today from 1PM-1:30AM"
                android:layout_gravity = "left"/>
                -->

            <!-- Eat...
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:text = "Eat today at 1PM, 6PM, 11:30PM"
                android:layout_gravity = "left"/>
                -->

            <!-- Be in Dark...
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:text = "Be in the Dark from 1:30PM to Bed"
                android:layout_gravity = "left"/>
                -->


            <!-- Sleep...-->
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:text = "Go to Sleep at "
                android:layout_gravity = "left"
                android:id = "@+id/text_view"
                />



        </LinearLayout>

        <!-- Miscellaneous-->
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight = "2"
            android:orientation = "vertical">

            <!-- Add Trip-->
            <Button
                android:layout_width="match_parent"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:text = "Add Trip"/>

            <!-- Connect Bluetooth-->
            <Button
                android:layout_width="match_parent"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:text = "Send Light Information"
                android:id = "@+id/sendLightInfo"/>

            <Button
                android:layout_width="match_parent"
                android:layout_height="0dp"
                android:layout_weight="1"
                android:text = "Receive Body Temperature Information"
                android:id = "@+id/receiveBodyTempInfo"
                android:onClick = "receiveBodyTempInfo"
                />



        </LinearLayout>








    </LinearLayout>



</RelativeLayout>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.teamfara.circadianrhythmmonitor2" >

    <!-- Allows bluetooth to be used from this app -->
    <uses-permission android:name="android.permission.BLUETOOTH" />
    <uses-permission android:name = "android.permission.BLUETOOTH_ADMIN"/>

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name"
            android:theme="@style/AppTheme.NoActionBar" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>

</manifest>

错误信息

10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 D/AndroidRuntime: Shutting down VM
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime: FATAL EXCEPTION: main
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime: Process: com.teamfara.circadianrhythmmonitor2, PID: 29694
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime: java.lang.IllegalStateException: Could not execute method of the activity
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.view.View$1.onClick(View.java:4298)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.view.View.performClick(View.java:5254)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.view.View$PerformClick.run(View.java:21179)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:739)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:95)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:145)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:6837)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:  Caused by: java.lang.reflect.InvocationTargetException
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.view.View$1.onClick(View.java:4293)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.view.View.performClick(View.java:5254) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.view.View$PerformClick.run(View.java:21179) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:739) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:95) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:145) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:6837) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:  Caused by: java.io.FileNotFoundException: /storage/emulated/0/temp.txt: open failed: EACCES (Permission denied)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at libcore.io.IoBridge.open(IoBridge.java:456)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.io.FileInputStream.<init>(FileInputStream.java:76)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.util.Scanner.<init>(Scanner.java:158)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.util.Scanner.<init>(Scanner.java:138)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at com.teamfara.circadianrhythmmonitor2.MainActivity.receiveBodyTempInfo(MainActivity.java:57)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.view.View$1.onClick(View.java:4293) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.view.View.performClick(View.java:5254) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.view.View$PerformClick.run(View.java:21179) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:739) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:95) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:145) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:6837) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:  Caused by: android.system.ErrnoException: open failed: EACCES (Permission denied)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at libcore.io.Posix.open(Native Method)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at libcore.io.IoBridge.open(IoBridge.java:442)
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.io.FileInputStream.<init>(FileInputStream.java:76) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.util.Scanner.<init>(Scanner.java:158) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.util.Scanner.<init>(Scanner.java:138) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at com.teamfara.circadianrhythmmonitor2.MainActivity.receiveBodyTempInfo(MainActivity.java:57) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.view.View$1.onClick(View.java:4293) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.view.View.performClick(View.java:5254) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.view.View$PerformClick.run(View.java:21179) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.os.Handler.handleCallback(Handler.java:739) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:95) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:145) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:6837) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404) 
10-23 21:33:55.398 29694-29694/com.teamfara.circadianrhythmmonitor2 E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199) 

有人能帮忙吗？

Answer 1

堆栈跟踪非常清晰:

Caused by: android.system.ErrnoException: open failed: EACCES (Permission denied)

如果搜索此错误，您会找到 this post .这基本上表示您缺少权限:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

但是，你正在尝试阅读，所以你想要:

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

Google 文档也 say the same thing :

In order to read or write files on the external storage, your app must acquire the READ_EXTERNAL_STORAGE