使用Google的Guava库，我们可以创建和写入文件容易地

package com.zetcode.writetofileex;

import com.google.common.io.Files;
import java.io.File;
import java.io.IOException;

public class WriteToFileEx {

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

        String fileName = "fruits.txt";
        File file = new File(fileName);

        String content = "banana, orange, lemon, apple, plum";

        Files.write(content.getBytes(), file);
    }
}

该示例在项目根目录中创建一个新的fruits.txt文件。

在Java8中，使用文件和路径，并使用trywithresources构造。

import java.io.BufferedWriter;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;

public class WriteFile{
    public static void main(String[] args) throws IOException {
        String file = "text.txt";
        System.out.println("Writing to file: " + file);
        // Files.newBufferedWriter() uses UTF-8 encoding by default
        try (BufferedWriter writer = Files.newBufferedWriter(Paths.get(file))) {
            writer.write("Java\n");
            writer.write("Python\n");
            writer.write("Clojure\n");
            writer.write("Scala\n");
            writer.write("JavaScript\n");
        } // the file will be automatically closed
    }
}

使用JFilechooser与客户一起阅读集合并保存到文件。

private void writeFile(){

    JFileChooser fileChooser = new JFileChooser(this.PATH);
    int retValue = fileChooser.showDialog(this, "Save File");

    if (retValue == JFileChooser.APPROVE_OPTION){

        try (Writer fileWrite = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(fileChooser.getSelectedFile())))){

            this.customers.forEach((c) ->{
                try{
                    fileWrite.append(c.toString()).append("\n");
                }
                catch (IOException ex){
                    ex.printStackTrace();
                }
            });
        }
        catch (IOException e){
            e.printStackTrace();
        }
    }
}

请注意，下面的每个代码示例都可能引发IOException。为了简洁起见，省略了Try/catch/finally块。有关异常处理的信息，请参阅本教程。

请注意，如果文件已经存在，下面的每个代码示例都将覆盖该文件

创建文本文件：

PrintWriter writer = new PrintWriter("the-file-name.txt", "UTF-8");
writer.println("The first line");
writer.println("The second line");
writer.close();

创建二进制文件：

byte data[] = ...
FileOutputStream out = new FileOutputStream("the-file-name");
out.write(data);
out.close();

Java 7+用户可以使用Files类写入文件：

创建文本文件：

List<String> lines = Arrays.asList("The first line", "The second line");
Path file = Paths.get("the-file-name.txt");
Files.write(file, lines, StandardCharsets.UTF_8);
//Files.write(file, lines, StandardCharsets.UTF_8, StandardOpenOption.APPEND);

创建二进制文件：

byte data[] = ...
Path file = Paths.get("the-file-name");
Files.write(file, data);
//Files.write(file, data, StandardOpenOption.APPEND);

Java 7+值得一试：

 Files.write(Paths.get("./output.txt"), "Information string herer".getBytes());

看起来很有希望。。。

我能找到的最简单的方法是：

Path sampleOutputPath = Paths.get("/tmp/testfile")
try (BufferedWriter writer = Files.newBufferedWriter(sampleOutputPath)) {
    writer.write("Hello, world!");
}

它可能只适用于1.7+。