Thread.currentThread().getStackTrace();

创建一个文本文件（注意：如果该文件存在，则会覆盖该文件）

PrintWriter writer = new PrintWriter("the-file-name.txt", "UTF-8");

writer.println("The first line");

writer.println("The second line");

writer.close();

创建一个位二进制文件（同样会覆盖这文件）

byte data[] = ...

FileOutputStream out = new FileOutputStream("the-file-name");

out.write(data);

out.close();

Java 7+ 用户可以用[`File`](http://docs.oracle.com/javase/7/docs/api/index.html?java/nio/file/Files.html)类来写文件

创建一个文本文件

List<String> lines = Arrays.asList("The first line", "The second line");

Path file = Paths.get("the-file-name.txt");

Files.write(file, lines, Charset.forName("UTF-8"));

创建一个二进制文件

byte data[] = ...

Path file = Paths.get("the-file-name");

Files.write(file, data);

在Java 7+中

try (Writer writer = new BufferedWriter(new OutputStreamWriter(

new FileOutputStream("filename.txt"), "utf-8"))) {

writer.write("something");

}

还有一些实用的方法如下：

* [`FileUtils.writeStringtoFile(..)`](https://commons.apache.org/proper/commons-io/apidocs/org/apache/commons/io/FileUtils.html#writeStringToFile%28java.io.File,%20java.lang.String,%20java.nio.charset.Charset%29) 来自于 commons-io 包

* [`Files.write(..)`](http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/io/Files.html#write%28java.lang.CharSequence,%20java.io.File,%20java.nio.charset.Charset%29) 来自于 guava

Note also that you can use a FileWriter, but it uses the default encoding,

which is often a bad idea - it's best to specify the encoding explicitly.

还要注意可以使用 `FileWriter`，但是它使用的是默认编码，这不是很好的方法，最好是明确指定编码

下面是来自于prior-to-java-7的原始方法

Writer writer = null;

try {

writer = new BufferedWriter(new OutputStreamWriter(

new FileOutputStream("filename.txt"), "utf-8"));

writer.write("Something");

} catch (IOException ex) {

// report

} finally {

try {writer.close();} catch (Exception ex) {/*ignore*/}

}

可以看[`Reading, Writing, and Creating Files`](http://docs.oracle.com/javase/tutorial/essential/io/file.html)(包含NIO2)

public class Program {

public static void main(String[] args) {

String text = "Hello world";

BufferedWriter output = null;

try {

File file = new File("example.txt");

output = new BufferedWriter(new FileWriter(file));

output.write(text);

} catch ( IOException e ) {

e.printStackTrace();

} finally {

if ( output != null ) output.close();

}

}

}

如果已经有想要写到文件中的内容，[`java.nio.file.Files`](https://docs.oracle.com/javase/7/docs/api/java/nio/file/Files.html) 作为 Java 7 附加部分的native I/O，提供了简单高效的方法来实现你的目标

基本上创建文件，写文件只需要一行，而且是只需一个方法调用！

下面的例子创建并且写了6个不同的文件来展示是怎么使用的

Charset utf8 = StandardCharsets.UTF_8;

List<String> lines = Arrays.asList("1st line", "2nd line");

byte[] data = {1, 2, 3, 4, 5};

try {

Files.write(Paths.get("file1.bin"), data);

Files.write(Paths.get("file2.bin"), data,

StandardOpenOption.CREATE, StandardOpenOption.APPEND);

Files.write(Paths.get("file3.txt"), "content".getBytes());

Files.write(Paths.get("file4.txt"), "content".getBytes(utf8));

Files.write(Paths.get("file5.txt"), lines, utf8);

Files.write(Paths.get("file6.txt"), lines, utf8,

StandardOpenOption.CREATE, StandardOpenOption.APPEND);

} catch (IOException e) {

e.printStackTrace();

}

下面是一个小程序来创建和写文件。该版本的代码比较长，但是可以容易理解

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.OutputStreamWriter;

import java.io.Writer;

public class writer {

public void writing() {

try {

//Whatever the file path is.

File statText = new File("E:/Java/Reference/bin/images/statsTest.txt");

FileOutputStream is = new FileOutputStream(statText);

OutputStreamWriter osw = new OutputStreamWriter(is);

Writer w = new BufferedWriter(osw);

w.write("POTATO!!!");

w.close();

} catch (IOException e) {

System.err.println("Problem writing to the file statsTest.txt");

}

}

public static void main(String[]args) {

writer write = new writer();

write.writing();

}

}

stackoverflow链接：