如何建立新檔案？(How to create a new file?)
問題描述 (Problem Description)
如何建立新檔案？
解決方案 (Solution)
此示例示範了使用File類的File()構造函數和file.createNewFile()方法建立新檔案的方法。import java.io.File;
import java.io.IOException;
public class Main {
public static void main(String[] args) {
try {
File file = new File("C:/myfile.txt");
if(file.createNewFile())System.out.println("Success!");
else System.out.println ("Error, file already exists.");
}
catch(IOException ioe) {
ioe.printStackTrace();
}
}
}
結果 (Result)
上面的代碼示例将産生以下結果(如果“myfile.txt之前不存在)Success!
以下是檔案建立的另一個示例示例import java.io.IOException;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.Arrays;
import java.util.List;
public class JavaApplication1 {
public static void main(String[] args) throws IOException {
createFileUsingFileClass();
createFileUsingFileOutputStreamClass();
createFileIn_NIO();
// TODO code application logic here
}
private static void createFileUsingFileClass() throws IOException {
File file = new File("c://testFile1.txt");
//Create the file
if (file.createNewFile()) {
System.out.println("File is created!");
} else {
System.out.println("File already exists.");
}
//Write Content
FileWriter writer = new FileWriter(file);
writer.write("Test data");
writer.close();
}
private static void createFileUsingFileOutputStreamClass() throws IOException {
String data = "Test data";
FileOutputStream out = new FileOutputStream("c://testFile2.txt");
out.write(data.getBytes());
out.close();
}
private static void createFileIn_NIO() throws IOException {
String data = "Test data";
Files.write(Paths.get("c://testFile3.txt"), data.getBytes());
List lines = Arrays.asList("1st line", "2nd line");
Files.write(Paths.get(
"file6.txt"), lines, StandardCharsets.UTF_8,
StandardOpenOption.CREATE, StandardOpenOption.APPEND);
}
}