FileReader rd1 = new FileReader(".txt");
br1 = new BufferedReader(rd1);
while((tempString1=br1.readLine())!=null)
{
a[index++] = tempString1;
}用String类数组接收a[index++] = tempString1提示java.lang.NullPointerException
用String s = tempString1;不会错误 为什么?
把readLine()读来的东西应如何放入数组?
br1 = new BufferedReader(rd1);
while((tempString1=br1.readLine())!=null)
{
a[index++] = tempString1;
}用String类数组接收a[index++] = tempString1提示java.lang.NullPointerException
用String s = tempString1;不会错误 为什么?
把readLine()读来的东西应如何放入数组?
ArrayList<String> lst = new ArrayList<String>();
while((tempString1=br1.readLine())!=null) {
lst.add(tempString1);
}
String[] arr = lst.toArray();
try {
rd1 = new FileReader("d:\\HelloWorld.java");
} catch (FileNotFoundException e1) {
e1.printStackTrace();
}
String tempString1;
List list = new ArrayList();
BufferedReader br1 = new BufferedReader(rd1);
try {
while ((tempString1 = br1.readLine()) != null) {
list.add(tempString1);
}
} catch (IOException e) {
e.printStackTrace();
}
Object[] o = list.toArray();
for (int i = 0; i < o.length; i++) {
System.out.println(o[i]);
}
}
不用ArrayList也行啊