public static void main(String[] args) {

        File file = new File("E:\\Temp\\hello.txt");
        
        try {
            if (!file.exists()) {
                file.createNewFile();
            }
            
            PrintWriter writer = new PrintWriter(file);
            writer.print("Hello, how are you");
            writer.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

------解决方案--------------------
java.io.FileInputStream;
java.io.FileOutputStream;
java.io.BufferedOutputStream;
java.io.BufferedReader;
java.io.InputStreamReader;
java.io.FileNotFoundException;
java.io.IOException;
java.io.File;


看一下这些API,对你的问题会有帮助的.