filenot found exception in android

问题

when i run this piece of code as normal java application in main it runs fine. but when i try to use the same code in onCreate in one of the activity it says file not found exception and prints nothing in logcat. i have tried every possible way but dont know whts the cause of the problem. Also in logcat the msg is like this filenotfound exception: /D:/android/Suyesh.2DV106.Assignment3/southern_cities.txt (no such file or directory) . is it because of the leading forward slash /D:/.. but i didnt put it there and when i try to print the path it doesnt contain that / in front of D. But when i print the absoulte path it contains that /D. Whats the problem here? I have also my manifest file as below.

public class TheCityMap extends Activity{
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);


    try {
        String strFile = Environment.getExternalStorageDirectory() +"/android/Suyesh.2DV106.Assignment3/southern_cities.txt";
        BufferedReader br = new BufferedReader(new FileReader(strFile));
        String strLine = null;
        StringTokenizer st = null;
        int lineNumber = 0, tokenNumber = 0;
        while( (strLine = br.readLine()) != null){
            lineNumber++;
            st = new StringTokenizer(strLine, ",");
            while(st.hasMoreTokens()){
                tokenNumber++;
                System.out.println("Line # " + lineNumber +", Token # " + tokenNumber+ ", Token : "+ st.nextToken());
            }
            tokenNumber = 0; 

        }
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } 
        }

}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="assignment3.demos"
  android:versionCode="1"
  android:versionName="1.0">
<uses-sdk android:minSdkVersion="10" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>

<application android:icon="@drawable/icon" android:label="@string/app_name">
    <activity android:name=".MainListActivity"
              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="TheCityMap"></activity>
    <uses-library android:name="com.google.android.maps"/>
    <uses-permission android:name="android.permission.INTERNET" > </uses-permission>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" > </uses-permission>
    <uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" > </uses-permission>
</application>

回答1:

Android is based on linux so things like "D:" should never work.

If the file is on sd card try this:

String strFile = Environment.getExternalStorageDirectory() + "/android/Suyesh.2DV106.Assignment3/southern_cities.txt";

At the end your path should be something like:
"/mnt/sdcard/android/Suyesh.2DV106.Assignment3/southern_cities.txt"

回答2:

Have you tried to use:

File file = new File(TheCityMap.class.getResource(/* name */));
BufferedReader reader = new BufferedReader(new FileReader( file ));

or:

new BufferedReader(new InputStreamReader(FlowAp.class.getResourceAsStream("" /* name */)))

回答3:

if D is your external storage directory (sdcard or flash), use Enviroment.getExternalStorageDirectory()

来源：https://stackoverflow.com/questions/7650301/filenot-found-exception-in-android

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filenotfoundexception