Can anyone help me why this error appear and where should i put the old.txt file to be seen by the code ? is there any solution ?
W/System.err: java.io.FileNotFoundException: old.txt (No such file or directory)
W/System.err: at java.io.FileInputStream.open(Native Method)
W/System.err: at java.io.FileInputStream.<init>(FileInputStream.java:146)
W/System.err: at java.io.FileInputStream.<init>(FileInputStream.java:99)
W/System.err: at java.io.FileReader.<init>(FileReader.java:58)
W/System.err: at FileUtils.readFileAsString(FileUtils.java:23)
W/System.err: at MainActivity.onclick(MainActivity.java:33)
W/System.err: at java.lang.reflect.Method.invoke(Native Method)
W/System.err: at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
W/System.err: at android.view.View.performClick(View.java:5637)
W/System.err: at android.view.View$PerformClick.run(View.java:22429)
W/System.err: at android.os.Handler.handleCallback(Handler.java:751)
W/System.err: at android.os.Handler.dispatchMessage(Handler.java:95)
W/System.err: at android.os.Looper.loop(Looper.java:154)
W/System.err: at android.app.ActivityThread.main(ActivityThread.java:6121)
W/System.err: at java.lang.reflect.Method.invoke(Native Method)
W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:889)
W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:779)
The code files are bellow:
MainActivity .java
import android.content.Context;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;
import java.io.IOException;
import java.io.FileNotFoundException;
public class MainActivity extends AppCompatActivity {
private Context context;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
context = getApplicationContext();
setContentView(R.layout.activity_main);
}
public void onclick(View view) {
FileUtils fu = new FileUtils();
try {
fu.writeFile("new.txt", fu.readFileAsString("old.txt"));
} catch (FileNotFoundException f) {
f.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
TextView displayTextView = (TextView) findViewById(R.id.display);
displayTextView.setText("Done!");
}
}
FileUtils .java
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class FileUtils {
/**
* Opens and reads a file, and returns the contents as one String.
*/
public static String readFileAsString(String filename)
throws IOException
{
BufferedReader reader = new BufferedReader(new FileReader(filename));
String line;
StringBuilder sb = new StringBuilder();
while ((line = reader.readLine()) != null)
{
sb.append(line + "\n");
}
reader.close();
return sb.toString();
}
/**
* Save the given text to the given filename.
* @param canonicalFilename Like /Users/al/foo/bar.txt
* @param text All the text you want to save to the file as one String.
* @throws IOException
*/
public static void writeFile(String canonicalFilename, String text)
throws IOException
{
File file = new File (canonicalFilename);
BufferedWriter out = new BufferedWriter(new FileWriter(file));
out.write(text);
out.close();
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity">
<Button
android:id="@+id/display_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="@dimen/activity_vertical_margin"
android:text="Display"
android:onClick="onclick"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Result: "
android:layout_marginTop="32dp"
android:layout_marginLeft="@dimen/activity_vertical_margin"/>
<TextView
android:id="@+id/display"
android:layout_width="match_parent"
android:layout_height="64dp"
android:layout_marginLeft="@dimen/activity_horizontal_margin"
android:layout_marginRight="@dimen/activity_horizontal_margin"
android:text=""
android:background="#e3e3e3"
style="@style/text_size" />
</LinearLayout>
