“Log file in an android studio”
In any programming language for tracking our application performance as well as for maintaining the history of any bugs or error, we generally create a log file in any temporary folder. That helps us to save our time for easily finding the bugs in a whole application.
Here we demonstrate the simple example for creating a log file in android studio-
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
tools:context="com.example.msclient009.readwritedatafromfile.MainActivity">
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="File Read/Write Operation"
android:layout_marginStart="40dp"
android:textColor="#f00"
android:textSize="22dp"
android:gravity="top" />
<LinearLayout
android:layout_width="wrap_content"
android:layout_below="@id/textView1"
android:orientation="horizontal"
android:layout_marginStart="0dp"
android:gravity="right"
android:layout_height="wrap_content">
<Button
android:id="@+id/write_file"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_below="@+id/textView1"
android:layout_marginTop="35dp"
android:text="Write File" />
<Button
android:id="@+id/read"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_below="@+id/textView1"
android:layout_marginTop="35dp"
android:text="Read File" />
</LinearLayout>
<TextView
android:id="@+id/displayText"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:textSize="18dp"
android:textColor="#07C"
android:layout_centerHorizontal="true"
android:layout_marginBottom="112dp"
android:text="Read File Text Display Here..." />
</RelativeLayout>
MainActivity.java
package com.example.msclient009.readwritedatafromfile;
import android.annotation.TargetApi;
import android.content.Context;
import android.icu.text.SimpleDateFormat;
import android.os.Build;
import android.os.Environment;
import android.support.annotation.RequiresApi;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Calendar;
import java.util.Date;
public class MainActivity extends AppCompatActivity {
Button readButton, writeButton;
TextView displayText;
File file;
static final int READ_BLOCK_SIZE = 100;
String fileName;
//Summernote summernote;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
readButton=(Button)findViewById(R.id.read);
writeButton=(Button)findViewById(R.id.write_file);
displayText=(TextView)findViewById(R.id.displayText);
// summernote=(Summernote)findViewById(R.id.summernote);
writeButton.setOnClickListener(new View.OnClickListener() {
@TargetApi(Build.VERSION_CODES.N)
@Override
public void onClick(View view) {
try{
int i=10;
int j=0;
int result=(int)i/j;
displayText.setText(" Result :"+result);
}catch(Exception e){
createLogErrorFile(e.toString());
}
}
});
readButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// displayText.setText("Read Button Click");
readFile();
}
});
downloadButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
displayText.setText("Download Button Click");
}
});
}
private void readFile() {
try {
FileInputStream fileIn=openFileInput(fileName);
InputStreamReader InputRead= new InputStreamReader(fileIn);
char[] inputBuffer= new char[READ_BLOCK_SIZE];
String s="";
int charRead;
while ((charRead=InputRead.read(inputBuffer))>0) {
// char to string conversion
String readstring=String.copyValueOf(inputBuffer,0,charRead);
s +=readstring;
}
InputRead.close();
displayText.setText(s);
}catch(Exception e){
e.printStackTrace();
}
}
@RequiresApi(api = Build.VERSION_CODES.N)
private void createLogErrorFile(String errMessage) {
try {
Date todayDate = Calendar.getInstance().getTime();
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
String currentDate = formatter.format(todayDate);
fileName = currentDate + "_logFile.txt";
/* File root = new File(Environment.getExternalStorageDirectory(), "LogErrorFolder");
if (!root.exists()) { // folder not found
root.mkdirs();
}
file = new File(root, fileName);*/
displayText.setText(fileName +" is created");
FileOutputStream fileout=openFileOutput(fileName, MODE_PRIVATE);
OutputStreamWriter outputWriter=new OutputStreamWriter(fileout);
outputWriter.write(" Log Entry : "+currentDate);
outputWriter.write("\n Error Message : "+errMessage);
outputWriter.write("\n ========================================\n\n");
outputWriter.close();
fileout.flush();
fileout.close();
//display file saved message
Toast.makeText(getBaseContext(), " Log File Created Successfully!", Toast.LENGTH_SHORT).show();
}
catch(Exception e){
e.printStackTrace();
}
}
}
Output :
After clicking on read file then the following screen will be display-
"Thanks!!! For Reading"
