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NETBEANS Java Basics 115 – Writing Text File
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Java Basics 115 – Writing Text File

STEPS

1) OPEN STARTUP PROJECT

Continue from previous tutorial.

2) Add Java Class.

2-1) Right-click Package name. Select New/Java Class.

2-2) Set Class Name as WriteFile.

Delete all comments and unnecessary codes, leaving only the following codes.

package textfiles;

public class WriteFile {

   

}

3) Add Import Statements.

package textfiles;

import java.io.FileWriter;

import java.io.PrintWriter;

import java.io.IOException;

public class WriteFile {

   

}

4) Add instructions to WriteFile Class.

4-1) Add variables and a constructor.

package textfiles;

import java.io.FileWriter;

import java.io.PrintWriter;

import java.io.IOException;

public class WriteFile {

    private String path;

    private boolean append_to_file = false;

    public WriteFile(String file_path) {

        path = file_path;

    }

}

4-2) Add a second constructor.

package textfiles;

import java.io.FileWriter;

import java.io.PrintWriter;

import java.io.IOException;

public class WriteFile {

    private String path;

    private boolean append_to_file = false;

    public WriteFile(String file_path) {

        path = file_path;

    }

    public WriteFile(String file_path, boolean append_value) {

        path = file_path;

        append_to_file = append_value;

    }

}

4-3) Add method to write file.

package textfiles;

import java.io.FileWriter;

import java.io.PrintWriter;

import java.io.IOException;

public class WriteFile {

    private String path;

    private boolean append_to_file = false;

    public WriteFile(String file_path) {

        path = file_path;

    }

    public WriteFile(String file_path, boolean append_value) {

        path = file_path;

        append_to_file = append_value;

    }

    public void writeToFile(String textLine) throws IOException {

        FileWriter write = new FileWriter(path, append_to_file);

        PrintWriter print_line = new PrintWriter(write);

        print_line.printf("%s" + "%n", textLine);

        print_line.close();

    }

}

5) Implement File Writing in Main Method

5-1) Append codes to the end of the existing codes.

package textfiles;

import java.io.IOException;

public class FileData {

    public static void main(String[] args) throws IOException {

        String file_name = "C:/test.txt";

        try {

            ReadFile file = new ReadFile(file_name);

            String[] aryLines = file.OpenFile();

            int i;

            for (i = 0; i < aryLines.length; i++) {

                System.out.println(aryLines[ i]);

            }

        } catch (IOException e) {

            System.out.println(e.getMessage());

        }

        /* WRITING DATA TO FILE */

        WriteFile data = new WriteFile( file_name , true );

        data.writeToFile( "This is another line of text" );

        System.out.println( "Text File Written To" );

    }

}

5-2) Run.

5-3) Run again.

5-3) Modify the codes to add TRY…CATCH Block.

package textfiles;

import java.io.IOException;

public class FileData {

    public static void main(String[] args) throws IOException {

        String file_name = "C:/test.txt";

        try {

            ReadFile file = new ReadFile(file_name);

            String[] aryLines = file.OpenFile();

            int i;

            for (i = 0; i < aryLines.length; i++) {

                System.out.println(aryLines[ i]);

            }

        } catch (IOException e) {

            System.out.println(e.getMessage());

        }

        /* WRITING DATA TO FILE */

        try {

            WriteFile data = new WriteFile(file_name, true);

            data.writeToFile("This is another line of text");

            System.out.println("Text File Written To");

        } catch (IOException e) {

            System.out.println(e.getMessage());

        }

    }

}

REFERENCE

http://www.homeandlearn.co.uk/java/write_to_textfile.html