امثلة على التعامل مع الملفات files باستخدام جافا

import java.io.File;
import java.io.PrintWriter;
import java.util.Scanner;

public class arrays_in_java{
    public static void main(String[] args) {
        try{
        String[] names = new String[100];
        int[] marks = new int[100];
        int count = readFromFile2Arrays(names, marks);
        printFileContents(names,marks,count);
        int lowestMark = getLowestMark(marks,count);
        System.out.println("lowest marks is : " + lowestMark);
        String highestmark_studnetname = getStudentNameWithHighestMarks(names,marks,count);
        System.out.println("student with highest marks is : " + highestmark_studnetname);
        calculateGradeofStudentToFile(names, marks, count);
        }catch (Exception e) {
            System.out.println("Err in main" + e);
        }
    }

    private static int readFromFile2Arrays(String[] names, int[] marks) {
        try{
            File myFile = new File("marks.txt");
            if(myFile.exists() && myFile.canRead()){
                Scanner fScan = new Scanner(myFile);
                String title = fScan.nextLine();
                int count = 0;
                while(fScan.hasNext()){
                    names[count]= fScan.next();
                    marks[count]= fScan.nextInt();
                    count++;
                }
                return count;
                
            }else{
                System.out.println("Error in reading from File"+ myFile.getName());
            }
            
        }catch (Exception e){
            System.out.println("Err in reading From File "+ e);
        }
        return 0;
    }

    private static void printFileContents(String[] names, int[] marks, int count) {
        System.out.println("ID"+"\t"+"Name\tMark");
        for (int i = 0; i < count xss=removed xss=removed min_mark=marks[i]; highestmark_studentname=names[0]; xss=removed xss=removed> highestmark_mark){
                highestmark_mark=marks[i];
            }
        }
        return highestmark_studentname;
    }
    public static char getGrade(int mark)
    {
      //Grading scheme is done using following criteria
//<=60 F
//>60 and <=70 : D
//>70 and <=80 : C
//>80 and <=90 : B
//>90 : A
    if(mark>90)
        return 'A';
    else if(mark>80)
        return 'B';
    else if(mark>70)
        return 'C';
    else if(mark>60)
        return 'D';
    else return 'F';
    }

    public static void calculateGradeofStudentToFile(String[] names, int[] marks, int count)
    {
        try {
            File myFile = new File("grades.txt");
            if(!myFile.exists())
                myFile.createNewFile();
            PrintWriter out = new PrintWriter(myFile);
            out.println("Student\tMarks\tGrade");
            for (int i = 0; i < count>

import java.io.*;
import java.util.Scanner;
public class arrays_in_java{
    public static void main(String[] args) {
        try{
        String[] vegetableName = new String[100];
        int[] calories = new int[100];
        double[] price = new double[100];
        int count = readFromFile2Arrays(vegetableName, calories,price);
        printFileContents(vegetableName, calories,price,count);
        String minCalVegName = getMinimumCaloriesName(vegetableName,calories,count);
        System.out.println("Vegetable Name with Min Cal\t" + minCalVegName);
        int totalCaloriesTaken = getTotalCalories(calories,count);
        int avgCalories = getAverageCalories(calories,count);
        double[] vat= new double[count];
        getDareebaOnVegetables(price,vat,count);
        writeIntoFileFromArray(vegetableName, calories,price,vat,count);
        }catch (Exception e) {
            System.out.println("Err in main" + e);
        }
    }

    private static int readFromFile2Arrays(String[] vegetableName, int[] calories, double[] price) {
        try{
            File myFile = new File("vegetable.txt");
            if(myFile.exists() && myFile.canRead()){
                Scanner fScan = new Scanner(myFile);
                String title = fScan.nextLine();
                int count = 0;
                while(fScan.hasNext()){
                    vegetableName[count]= fScan.next();
                    calories[count]= fScan.nextInt();
                    price[count]= fScan.nextDouble();
                    count++;
                }
                return count;
                
            }else{
                System.out.println("Error in reading from File"+ myFile.getName());
            }
            
        }catch (Exception e){
            System.out.println("Err in reading From File "+ e);
        }
        return 0;
    }

    private static void printFileContents(String[] vegetableName, int[] calories, double[] price, int count) {
        System.out.println("ID"+"\t"+"Name\tcalories\tprice");
        for (int i = 0; i < count name =vegetableName[0]; xss=removed xss=removed name=vegetableName[i]; xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed>

public class arrays_in_java{
    ///i will read two array one of type String and other of type int then i will store both of them in new File///
package arryfile;
import java.util.Scanner;
import java.io.File;
import java.io.PrintWriter;
public class Read2ArrFromFile {
    static Scanner input = new Scanner(System.in);
    public static void main(String[] args) {
        try {
            String[] name = new String[100];
            int[] marks = new int[100];
            int count = readFromFile2Arr(name,marks);
            printArray(name,marks,count);
            writeArraytoFile(name,marks,count);
            
        } catch (Exception e) {
            System.out.println("Err in main "+ e);
        }
    }

    private static int readFromFile2Arr(String[] name, int[] marks) {
        try {
            File myFile = new File("std.txt");
            if(myFile.exists() && myFile.canRead()){
                // read from file we use Scanner
                // write into we use PrintWriter
                Scanner fScan = new Scanner(myFile);
                int count = 0; 
                while(fScan.hasNext()){
                    name[count]= fScan.next();
                    marks[count]= fScan.nextInt();
                    count++;
                }
                return count;
            }else{
                System.out.println("Err in reading From File");
            }
            
        } catch (Exception e) {
            System.out.println("Err in read "+ e);
        }
        return 0;
    }

    private static void printArray(String[] name, int[] marks, int count) {
        for (int i = 0; i < count xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed> max){
                max = marks[i];
                maxName = name[i];
            }
        }
        return maxName;
    }

    private static int findMaxMarks(String[] name, int[] marks, int count) {
        int max = marks[0];
        for (int i = 0; i < count> max)
                max = marks[i];
        }
        return max;
    }
}
}

/*
i will read two array one of type String and other of type int
then i will store both of them in new File
Tell me who has got max marks
*/
import java.util.Scanner;
import java.io.File;
import java.io.PrintWriter;
public class Read2ArrFromFile {
    static Scanner input = new Scanner(System.in);
    public static void main(String[] args) {
        try {
            String[] name = new String[100];
            int[] marks = new int[100];
            int count = readFromFile2Arr(name,marks);
            printArray(name,marks,count);
            writeArraytoFile(name,marks,count);
            String maxName = findMaxMarksName(name,marks,count);
            int maxMarks = findMaxMarks(name,marks,count);
            System.out.println("Max Name " + maxName + " "+ maxMarks);
        } catch (Exception e) {
            System.out.println("Err in main "+ e);
        }
    }

    private static int readFromFile2Arr(String[] name, int[] marks) {
        try {
            File myFile = new File("std.txt");
            if(myFile.exists() && myFile.canRead()){
                // read from file we use Scanner
                // write into we use PrintWriter
                Scanner fScan = new Scanner(myFile);
                int count = 0; 
                while(fScan.hasNext()){
                    name[count]= fScan.next();
                    marks[count]= fScan.nextInt();
                    count++;
                }
                return count;
            }else{
                System.out.println("Err in reading From File");
            }
            
        } catch (Exception e) {
            System.out.println("Err in read "+ e);
        }
        return 0;
    }

    private static void printArray(String[] name, int[] marks, int count) {
        for (int i = 0; i < count xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed> max){
                max = marks[i];
                maxName = name[i];
            }
        }
        return maxName;
    }

    private static int findMaxMarks(String[] name, int[] marks, int count) {
        int max = marks[0];
        for (int i = 0; i < count> max)
                max = marks[i];
        }
        return max;
    }
}
}

/*
i will read four array one of type String and other of type int
then i will store both of them in new File
Tell me who has got max marks
*/
import java.util.Scanner;
import java.io.File;
import java.io.PrintWriter;
public class Read3ArrFromFile {
    static Scanner input = new Scanner(System.in);
    public static void main(String[] args) {
        try {
            String[] name = new String[100];
            int[] marks = new int[100];
            char[] grade = new char[100];
            double[] age = new double[100];
            int count = readFromFile2Arr(name,marks,grade,age);
            printArray(name,marks,grade,age,count);
            writeArraytoFile(name,marks,grade,age,count);
            String maxName = findMaxMarksName(name,marks,count);
            int maxMarks = findMaxMarks(name,marks,count);
            System.out.println("Max Name " + maxName + " "+ maxMarks);
        } catch (Exception e) {
            System.out.println("Err in main "+ e);
        }
    }

    private static int readFromFile2Arr(String[] name, int[] marks, char[] grade, double[] age) {
        try {
            File myFile = new File("std1.txt");
            if(myFile.exists() && myFile.canRead()){
                // read from file we use Scanner
                // write into we use PrintWriter
                Scanner fScan = new Scanner(myFile);
                int count = 0; 
                while(fScan.hasNext()){
                    name[count]= fScan.next();
                    marks[count]= fScan.nextInt();
                    grade[count]=fScan.next().charAt(0);
                    age[count]=fScan.nextDouble();
                    count++;
                }
                return count;
            }else{
                System.out.println("Err in reading From File");
            }
            
        } catch (Exception e) {
            System.out.println("Err in read "+ e);
        }
        return 0;
    }

    private static void printArray(String[] name, int[] marks, char[] grade, double[] age, int count) {
        for (int i = 0; i < count xss=removed xss=removed xss=removed xss=removed xss=removed xss=removed> max){
                max = marks[i];
                maxName = name[i];
            }
        }
        return maxName;
    }

    private static int findMaxMarks(String[] name, int[] marks, int count) {
        int max = marks[0];
        for (int i = 0; i < count> max)
                max = marks[i];
        }
        return max;
    }
}
}

import java.io.File;
import java.io.PrintWriter;
import java.util.Scanner;


public class File_example {
 
    public static void main(String[] args) {
   
    try{
    File f=new File("dob.txt");
    
    if(!f.exists())
    {
        f.createNewFile();
        PrintWriter pw=new PrintWriter(f);
        pw.println("Name\tID\tDateOfBirth");
        pw.println("skaik\t2\t1995");
        pw.println("rano\t3\t1796");
        pw.println("rokie\t4\t1996");
        pw.println("sgaiy\t5\t1975");
        pw.close();
    }
    
    Scanner fileReader=new Scanner(f);
    while(fileReader.hasNext())
    {
        System.out.println(fileReader.nextLine());
    }
    
    fileReader.close();
}
    catch(Exception e)
    {
        System.out.println(e);
    }
    } 
}

import java.util.Scanner;
import java.io.PrintWriter;
import java.io.File;
public class reading_from_file {
    static Scanner input = new Scanner(System.in);
    public static void main(String[] args) {
        try {
            File myFile = new File("dob.txt");
            if(!(myFile.exists()))
                myFile.createNewFile();
            Scanner fScan = new Scanner(myFile); // read from File
            readDOB(fScan);
}catch(Exception e){System.out.println("Error in Main" + e);}
    }
    private static void readDOB(Scanner fScan) {
        try {
            while(fScan.hasNext()){
                String name = fScan.next();
                int ID = fScan.nextInt();
                int dob = fScan.nextInt();
                System.out.println(name +" : "+ ID+" : "+dob);
            }
            
        } catch (Exception e) {
            System.out.println("Error in read "+ e);
        }
   
    }
}

package javaapplication11;
import java.io.File;
import java.io.PrintWriter;
import java.util.Scanner;
public class JavaApplication11 {

    public static void main(String[] args) {

        try{
        System.out.println("welcome");
        Scanner input=new Scanner(System.in);
        File f=new File("test.txt");
        if(f.exists())
        {
            //start writing...
            PrintWriter pw=new PrintWriter(f);
            pw.println("this is the first line in file");
            pw.close();
        }
        else 
        {
            System.out.println("file not found");
            f.createNewFile();
        }
        }
        catch(Exception e){
            System.out.println(e);
        }
        }
    }
    
}