Java File createNewFile()
[Java File] Java File
createNewFile() Java java.io.File
public boolean createNewFile() throws IOException
-
true -
false
IOException I/O
createNewFile()
import java.io.File;
import java.io.IOException;
public class CreateFileExample {
public static void main(String[] args) {
// File
File file = new File("example.txt");
try {
//
boolean created = file.createNewFile();
if (created) {
System.out.println("");
} else {
System.out.println("");
}
} catch (IOException e) {
System.out.println(": " + e.getMessage());
}
}
}
import java.io.IOException;
public class CreateFileExample {
public static void main(String[] args) {
// File
File file = new File("example.txt");
try {
//
boolean created = file.createNewFile();
if (created) {
System.out.println("");
} else {
System.out.println("");
}
} catch (IOException e) {
System.out.println(": " + e.getMessage());
}
}
}
createNewFile()
-
example.txt
-
IOException
1
File file = new File("nonexistent_dir/example.txt");
try {
file.createNewFile(); // IOException
} catch (IOException e) {
e.printStackTrace();
}
try {
file.createNewFile(); // IOException
} catch (IOException e) {
e.printStackTrace();
}
File file = new File("nonexistent_dir/example.txt");
file.getParentFile().mkdirs(); //
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
file.getParentFile().mkdirs(); //
try {
file.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
2
IOException
FileOutputStream
// FileOutputStream
try (FileOutputStream fos = new FileOutputStream("file1.txt")) {
//
}
// createNewFile()
File file = new File("file2.txt");
file.createNewFile(); //
try (FileOutputStream fos = new FileOutputStream("file1.txt")) {
//
}
// createNewFile()
File file = new File("file2.txt");
file.createNewFile(); //
Files.createFile()
Java 7 NIO.2 API Files.createFile()
Path path = Paths.get("example.txt");
try {
Files.createFile(path); // FileAlreadyExistsException
} catch (IOException e) {
e.printStackTrace();
}
try {
Files.createFile(path); // FileAlreadyExistsException
} catch (IOException e) {
e.printStackTrace();
}
Files.createFile()
-
createNewFile() -
IOException - try-with-resources
- Java 7+
Files.createFile()
import java.io.File;
import java.io.IOException;
public class AdvancedFileCreation {
public static void main(String[] args) {
String fileName = "data/output/log.txt";
File logFile = new File(fileName);
//
File parentDir = logFile.getParentFile();
if (parentDir != null && !parentDir.exists()) {
boolean dirsCreated = parentDir.mkdirs();
if (!dirsCreated) {
System.err.println("");
return;
}
}
try {
if (logFile.createNewFile()) {
System.out.println(": " + logFile.getAbsolutePath());
} else {
System.out.println(": " + logFile.getAbsolutePath());
}
} catch (IOException e) {
System.err.println(": " + e.getMessage());
}
}
}
import java.io.IOException;
public class AdvancedFileCreation {
public static void main(String[] args) {
String fileName = "data/output/log.txt";
File logFile = new File(fileName);
//
File parentDir = logFile.getParentFile();
if (parentDir != null && !parentDir.exists()) {
boolean dirsCreated = parentDir.mkdirs();
if (!dirsCreated) {
System.err.println("");
return;
}
}
try {
if (logFile.createNewFile()) {
System.out.println(": " + logFile.getAbsolutePath());
} else {
System.out.println(": " + logFile.getAbsolutePath());
}
} catch (IOException e) {
System.err.println(": " + e.getMessage());
}
}
}
createNewFile() Java Java NIO.2 API Files
[Java File] Java File