public static void main(String[] args) throws IOException { FileWriter fw = new FileWriter("c:/s1.txt");
BufferedWriter bw = new BufferedWriter(fw);
FileReader fr = new FileReader("c:/s1.txt");
BufferedReader br = new BufferedReader(fr);
FileWriter fw2 = new FileWriter("c:/s2.txt");
BufferedWriter bw2 = new BufferedWriter(fw);
bw.write("明月几时有,把酒问青天。");//尝试将这一句改为 bw.write("明月几时有,把酒问青天。\n");
//却没有实现换行,为什么? bw.newLine();
bw.write("不知天上宫阙,今夕是何年。"); System.out.println("Copying in progress......"); while(br.ready()){
bw2.write(br.readLine());
}
//通过上面的循环,本意是将s1.txt中的文字复制到s2.txt中的,结果,发现s2文件为空!!
//经过调试发现,原来br.readline()竟然为null!!为什么??
System.out.println("Success!"); bw.close();
fw.close();
fr.close();
br.close();
bw2.close();
fw2.close();
}
BufferedWriter bw = new BufferedWriter(fw);
FileReader fr = new FileReader("c:/s1.txt");
BufferedReader br = new BufferedReader(fr);
FileWriter fw2 = new FileWriter("c:/s2.txt");
BufferedWriter bw2 = new BufferedWriter(fw);
bw.write("明月几时有,把酒问青天。");//尝试将这一句改为 bw.write("明月几时有,把酒问青天。\n");
//却没有实现换行,为什么? bw.newLine();
bw.write("不知天上宫阙,今夕是何年。"); System.out.println("Copying in progress......"); while(br.ready()){
bw2.write(br.readLine());
}
//通过上面的循环,本意是将s1.txt中的文字复制到s2.txt中的,结果,发现s2文件为空!!
//经过调试发现,原来br.readline()竟然为null!!为什么??
System.out.println("Success!"); bw.close();
fw.close();
fr.close();
br.close();
bw2.close();
fw2.close();
}
public static void main(String[] args) throws IOException {
FileWriter fw = new FileWriter("c:/s1.txt");
BufferedWriter bw = new BufferedWriter(fw);
bw.write("明月几时有,把酒问青天。\r\n");//改为\r\n
bw.write("不知天上宫阙,今夕是何年。");
bw.close();//用完了就将它关闭,如果你是懒人,可以只关闭最外层流i
//重新打开它
FileReader fr = new FileReader("c:/s1.txt");
BufferedReader br = new BufferedReader(fr);
FileWriter fw2 = new FileWriter("c:/s2.txt");
BufferedWriter bw2 = new BufferedWriter(fw2);//写错了fw2
while (br.ready()) {
bw2.write(br.readLine());
bw2.newLine();//添加换行符
}
bw2.close();//通常先关闭写,再关闭读
br.close();
}
public static void main(String[] args) throws IOException { FileWriter fw = new FileWriter("c:/s1.txt");
BufferedWriter bw = new BufferedWriter(fw); bw.write("明月几时有,把酒问青天。\r\n");//尝试将这一句改为 bw.write("明月几时有,把酒问青天。\n");
//却没有实现换行,为什么? windows加上\r就可以了// bw.newLine();
bw.write("不知天上宫阙,今夕是何年。"); System.out.println("Copying in progress......");
bw.close();//先保证内容写到文件 FileReader fr = new FileReader("c:/s1.txt");
BufferedReader br = new BufferedReader(fr); FileWriter fw2 = new FileWriter("c:/s2.txt");
BufferedWriter bw2 = new BufferedWriter(fw2); //这里更改,原来是fw
// while(br.ready()){
// bw2.write(br.readLine());
// } 复制内容的API调用有问题 看下面的
String str="";
while((str=br.readLine())!=null){
bw2.write(str);
}//通过上面的循环,本意是将s1.txt中的文字复制到s2.txt中的,结果,发现s2文件为空!!
//经过调试发现,原来br.readline()竟然为null!!为什么??
System.out.println("Success!");
bw2.close();
br.close();
}
}