在Java 7中，您可以执行以下操作：

String content = "Hello File!";
String path = "C:/a.txt";
Files.write( Paths.get(path), content.getBytes());

这里有更多信息：http://www.drdobbs.com/jvm/java-se-7-new-file-io/231600403

看看Java文件API

快速示例：

try (PrintStream out = new PrintStream(new FileOutputStream("filename.txt"))) {
    out.print(text);
}

使用Java 7：

public static void writeToFile(String text, String targetFilePath) throws IOException
{
    Path targetPath = Paths.get(targetFilePath);
    byte[] bytes = text.getBytes(StandardCharsets.UTF_8);
    Files.write(targetPath, bytes, StandardOpenOption.CREATE);
}

我倾向于尽可能依赖于库来进行这种操作。这使我不太可能意外地忽略一个重要的步骤（如上面狼鹬犯的错误）。上面建议了一些库，但我最喜欢的是GoogleGuava。Guava有一个名为Files的类，非常适合此任务：

// This is where the file goes.
File destination = new File("file.txt");
// This line isn't needed, but is really useful 
// if you're a beginner and don't know where your file is going to end up.
System.out.println(destination.getAbsolutePath());
try {
    Files.write(text, destination, Charset.forName("UTF-8"));
} catch (IOException e) {
    // Useful error handling here
}

使用Apache Commons IO中的FileUtils.writeStringToFile（）。无需重新发明这个轮子。

你可以这样做：

import java.io.*;
import java.util.*;

class WriteText
{
    public static void main(String[] args)
    {   
        try {
            String text = "Your sample content to save in a text file.";
            BufferedWriter out = new BufferedWriter(new FileWriter("sample.txt"));
            out.write(text);
            out.close();
        }
        catch (IOException e)
        {
            System.out.println("Exception ");       
        }

        return ;
    }
};