FileWriter不覆盖

/*演示对已有文件进行读写：*/import java.io.*;class  FileWriteDemo2{public static void main(String[] args) {FileWriter fw = null;try{//  传递一个true，代表不覆盖原有内容。fw = new FileWriter("Demo.txt",true);fw.write("kjflasjdk");}catch (IOException ex){System.out.println("创建文件流错误");}finally{try{if(fw != null){fw.close();}}catch (IOException ex){System.out.println("关闭流错误。");}}}}