Merge pull request #3 from jayanpraveen/master

added file handling

Author: engineerscodes

FileHandling/FileWriterDemo.java

@@ -0,0 +1,19 @@
+package com.jayan;
+
+import java.io.*;
+import java.util.*;
+
+public class FileWriterDemo {
+    public static void main(String[] args) throws IOException {
+        String pathToFile;
+        pathToFile = "/Users/jayanpraveen/Desktop/hello-world/FILE_NAME.txt";
+
+        File file = new File(pathToFile);
+        FileWriter writer = new FileWriter(file, true); 
+
+        writer.write("Hello\n");
+        writer.write("Java\n");
+
+        writer.close();
+    }
+}

FileHandling/PrintWriterDemo.java

@@ -0,0 +1,39 @@
+package com.jayan;
+
+import java.io.*;
+import java.util.*;
+
+public class PrintWriterDemo {
+    public static void main(String[] args) 
+    throws IOException {
+
+    String pathToFile;
+    pathToFile = "set-path-file.txt";
+
+    File file = new File(pathToFile);
+    PrintWriter printWriter = new PrintWriter(file);
+
+    printWriter.print("Hello");
+    printWriter.println("Java");
+    printWriter.println(123);
+    printWriter.printf("You have %d %s", 400, "gold coins");
+
+    printWriter.close();
+
+    }
+
+        // File file = new File("/Users/jayanpraveen/Desktop/hello-world/printwriter.txt");
+        // try(
+        // PrintWriter printWriter = new PrintWriter(file))
+        // {
+        //     printWriter.print("Hello"); // prints a string
+        //     printWriter.println("Java"); // prints a string and then terminates the line
+        //     printWriter.println(123); // prints a number
+        //     printWriter.printf("You have %d %s", 400, "gold coins"); // prints a formatted string
+        // }catch(
+        // IOException e)
+        // {
+        //     System.out.printf("An exception occurs %s", e.getMessage());
+        // }
+    
+}

FileHandling/countEvenNumsFileDemo.java

@@ -0,0 +1,38 @@
+package com.jayan;
+
+import java.io.*;
+import java.util.*;
+
+public class countEvenNumsFileDemo {
+    public static void main(String[] args)
+    {
+        String pathToFile;
+        pathToFile = "set-path-file.txt";
+
+        int countWords = 0;
+
+        try
+        {
+            File file = new File(pathToFile);
+            Scanner scanner = new Scanner(file);
+            int value = scanner.nextInt();
+
+            while (scanner.hasNext())
+            {
+
+                System.out.print(value + " ");
+
+                if (value % 2 == 0)
+                    countWords ++;
+
+                value = scanner.nextInt();
+                
+            }
+            System.out.println("WORDS: " + countWords);
+        }
+        catch(FileNotFoundException e)
+        {
+            System.out.println("No file found:" );
+        }
+}
+}

FileHandling/readFileDemo.java

@@ -0,0 +1,27 @@
+package com.jayan;
+
+import java.io.IOException;
+import java.nio.file.*;
+// import java.nio.file.Paths;
+
+public class readFileDemo
+{
+    public static String readFileAsString(String fileName) throws IOException
+    {
+        return new String(Files.readAllBytes(Paths.get(fileName)));
+    }
+
+    public static void main(String[] args)
+    {
+        String pathToHelloWorldJava = "set-path-file.txt";
+        try
+        {
+            System.out.println(readFileAsString(pathToHelloWorldJava));
+            
+        }
+        catch (IOException e)
+        {
+            System.out.println("Cannot read file: " + e.getMessage());
+        }
+    }
+}