Sử dụng thư viện NIO để đọc ghi file trong Java
1. Đọc File
Tạo class ReadFileWithJavaNIO.java
package com.loop.io;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.util.ArrayList;
public class ReadFileWithJavaNIO {
/**
* Create by Cuder
*
* @throws IOException
*/
public static void main(String[] args) throws IOException {
File f = new File("resource/textFile.txt");
ArrayList<String> res = (ArrayList<String>) Files.readAllLines(f
.toPath());
for (int i = 0; i < res.size(); i++) {
System.out.println(res.get(i));
}
}
}
Kết quả
Line 1
Line 2
Line 3
Line 4
Line 5
2. Ghi File
Tạo class WriteNewFileWithJavaNIO.java
package com.loop.io;
import java.io.File;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.StandardOpenOption;
import java.util.ArrayList;
public class WriteNewFileWithJavaNIO {
/**
* Create by Cuder
*
* @throws IOException
*/
public static void main(String[] args) throws IOException {
ArrayList<String> data = new ArrayList<>();
data.add("line content 1");
data.add("line content 2");
data.add("line content 3");
data.add("line content 4");
data.add("line content 5");
data.add("line content 6");
File f = new File("resource/fileWrite7.txt");
Files.write(f.toPath(), data, Charset.forName("UTF-8"),
StandardOpenOption.CREATE, StandardOpenOption.WRITE);
}
}
Kết quả fileWrite7.txt
line content 1
line content 2
line content 3
line content 4
line content 5
line content 6
3. Thêm nội dung file
Nôi dung fileWrite7.txt
line content 1
line content 2
line content 3
line content 4
line content 5
line content 6
Tạo class AppendContentFileWithJavaNIO.java
package com.loop.io;
import java.io.File;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.StandardOpenOption;
import java.util.ArrayList;
public class AppendContentFileWithJavaNIO {
/**
* Create by Cuder
*
* @throws IOException
*/
public static void main(String[] args) throws IOException {
ArrayList<String> data = new ArrayList<>();
data.add("line content 1");
data.add("line content 2");
data.add("line content 3");
data.add("line content 4");
data.add("line content 5");
data.add("line content 6");
data.add("line content 7");
File f = new File("resource/fileWrite7.txt");
Files.write(f.toPath(), data, Charset.forName("UTF-8"),
StandardOpenOption.APPEND, StandardOpenOption.WRITE);
}
}
Kết quả fileWrite7.txt
line content 1
line content 2
line content 3
line content 4
line content 5
line content 6
line content 1
line content 2
line content 3
line content 4
line content 5
line content 6
line content 7
