只有一行！路径和行是字符串

import java.nio.file.Files;
import java.nio.file.Paths;

Files.write(Paths.get(path), lines.getBytes());

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。

我认为这是最短的路：

FileWriter fr = new FileWriter("your_file_name.txt"); // After '.' write
// your file extention (".txt" in this case)
fr.write("Things you want to write into the file"); // Warning: this will REPLACE your old file content!
fr.close();

在Java 7及以上版本中：

try (Writer writer = new BufferedWriter(new OutputStreamWriter(
              new FileOutputStream("filename.txt"), "utf-8"))) {
   writer.write("something");
}

但有一些有用的实用程序：

来自commons io的FileUtils.writeStringtoFile（..）来自番石榴的文件.write（..）

还要注意，您可以使用FileWriter，但它使用默认编码，这通常是一个坏主意-最好显式指定编码。

以下是Java 7之前的原始答案

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*/}
}

另请参阅：读取、写入和创建文件（包括NIO2）。

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();
        }
    }
}

这里有一个创建或覆盖文件的小示例程序。这是一个长版本，因此可以更容易理解。

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();
    }
}