String s="ada";
char[] a=s.toCharArray(); 将字符串转换成字符数组

public class test{ public static void main(String[]args) { File f =new File("D:d/write.txt"); Writer writer=null; try { writer=new FileWriter(f); //写法一 /*String s="adad afaff哈哈哈"; char[] ch=s.toCharArray(); //从字符串到字符数组 writer.write(ch,0,ch.length); **write.flush();***/ //写法二 /*String s="adad afaff哈哈哈2"; writer.write(s,0,s.length()); //因为字符串就是字符数组，所以可以直接使用 writer.write("addd"); //可实现多次写入 writer.write("fff"); **writer.flush();** */ //写法三 /*writer.append("adad").append("aaa\n"); **writer.flush();***/ }catch(FileNotFoundException e) { e.printStackTrace(); }catch(IOException e) { e.printStackTrace(); }finally { try { if(null!=writer) { **writer.close();** } }catch(IOException e) { e.printStackTrace(); } }}

}