Các phương pháp đọc/ghi tệp dữ liệu khác nhau trong Java

Farewell! thou art too dear for my possessing, 

And like enough thou know’st thy estimate, 

The charter of thy worth gives thee releasing: 

My bonds in thee are all determinate. 

For how do I hold thee but by thy granting, 

And for that riches where is my deserving? 

The cause of this fair gift in me is wanting, 

And so my patent back again is swerving. 

Thy self thou gav’st, thy own worth then not knowing, 

Or me to whom thou gav’st it, else mistaking, 

So thy great gift upon misprision growing, 

Comes home again, on better judgement making. 

Thus have I had thee as a dream doth flatter, 

In sleep a king, but waking no such matter.

package file;

// Import package cần thiết

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.util.Scanner;

import java.util.logging.Level;

import java.util.logging.Logger;

public class ReadFileWithScanner {

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

        String url = “F:\\content-niit\\file-content.txt”;

        // Đọc dữ liệu từ File với Scanner

        FileInputStream fileInputStream = new FileInputStream(url);

        Scanner scanner = new Scanner(fileInputStream);

        try {

            while (scanner.hasNextLine()) {

                System.out.println(scanner.nextLine());

            }

        } finally {

            try {

                scanner.close();

                fileInputStream.close();

            } catch (IOException ex) {

                Logger.getLogger(ReadFileWithBufferedReader.class.getName())

                                .log(Level.SEVERE, null, ex);

            }

        }

    }

}

package file;

import java.io.BufferedReader;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStreamReader;

import java.util.logging.Level;

import java.util.logging.Logger;

public class ReadFileWithBufferedReader {

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

        String url = “F:\\content-niit\\file-content.txt”;

        // Đọc dữ liệu từ File với BufferedReader

        FileInputStream fileInputStream = null;

        BufferedReader bufferedReader = null;

        try {

            fileInputStream = new FileInputStream(url);

            bufferedReader = new BufferedReader(new InputStreamReader(fileInputStream));

            String line = bufferedReader.readLine();

            while (line != null) {

                System.out.println(line);

                line = bufferedReader.readLine();

            }

        } catch (FileNotFoundException ex) {

            Logger.getLogger(ReadFileWithBufferedReader.class.getName()

                            .log(Level.SEVERE, null, ex);

        } catch (IOException ex) {

            Logger.getLogger(ReadFileWithBufferedReader.class.getName())

                            .log(Level.SEVERE, null, ex);

        } finally {

            try {

                bufferedReader.close();

                fileInputStream.close();

            } catch (IOException ex) {

                Logger.getLogger(ReadFileWithBufferedReader.class.getName()

                                .log(Level.SEVERE, null, ex);

            }

        }

    }

}

package file;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.IOException;

import java.util.logging.Level;

import java.util.logging.Logger;

public class ReadFileWithFileAndFileReader {

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

        String url = “F:\\content-niit\\file-content.txt”;

        // Đọc dữ liệu từ File với File và FileReader

        File file = new File(url);

        BufferedReader reader = new BufferedReader(new FileReader(file));

        try {

            String line = reader.readLine();

            while (line != null) {

                System.out.println(line);

                line = reader.readLine();

            }

        } catch (FileNotFoundException ex) {

            Logger.getLogger(ReadFileWithBufferedReader.class.getName())

                            .log(Level.SEVERE, null, ex);

        } catch (IOException ex) {

            Logger.getLogger(ReadFileWithBufferedReader.class.getName())

                            .log(Level.SEVERE, null, ex);

        } finally {

            try {

                reader.close();

                // file.close();

            } catch (IOException ex) {

                Logger.getLogger(ReadFileWithBufferedReader.class.getName())

                                .log(Level.SEVERE, null, ex);

            }

        }

    }

}

<?xml version=“1.0”?>

<family>

    <member id=“4”>

        <firstname>Michael</firstname>

        <lastname>Corleone</lastname>

        <age>22</age>

        <earnings>$1.000.000</earnings>

    </member>

    <member id=“3”>

        <firstname>Tom</firstname>

        <lastname>Hagen</lastname>

        <age>26</age>

        <earnings>$300.000</earnings>

    </member>

</family>

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;

import org.w3c.dom.NodeList;

import org.w3c.dom.Node;

import org.w3c.dom.Element;

import java.io.File;

public class ReadFileXML {

    public static void main(String argv[]) {

        String url = “F:\\content-niit\\family.xml”;

        try {

            File fXmlFile = new File(url);

            DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();

            DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();

            Document doc = dBuilder.parse(fXmlFile);

            doc.getDocumentElement().normalize();

            NodeList nList = doc.getElementsByTagName(“member”);

            for (int temp = 0; temp < nList.getLength(); temp++) {

                Node nNode = nList.item(temp);

                if (nNode.getNodeType() == Node.ELEMENT_NODE) {

                    Element eElement = (Element) nNode;

                    System.out.println(“Con thứ: “

                                        + eElement.getAttribute(“id”));

                    System.out.println(“Tên: “

                                        + eElement.getElementsByTagName(“firstname”)

                                        .item(0).getTextContent());

                    System.out.println(“Họ: “

                                        + eElement.getElementsByTagName(“lastname”)

                                        .item(0).getTextContent());

                    System.out.println(“Tuổi: “

                                        + eElement.getElementsByTagName(“age”)

                                        .item(0).getTextContent());

                    System.out.println(“Thu nhập: “

                                        + eElement.getElementsByTagName(“earnings”)

                                        .item(0).getTextContent());

                    System.out.println(” “);

                }

            }

        } catch (Exception e) {

            e.printStackTrace();

        }

    }

}