小弟有段程序 运行时出现 java.lang.NullPointerException 错误,若将17行 ss = s.toCharArray(); 去掉,运行时则没错,但我需要这部分功能,该怎么实现呢
import java.io.*;
import java.lang.*;public class Test {
public static void main(String[] args) {
try {
FileReader input = new FileReader("test1.txt");
BufferedReader br = new BufferedReader(input);
FileWriter output = new FileWriter("temp1.txt");
BufferedWriter bw = new BufferedWriter(output);
String s = br.readLine();
while ( s!=null ) {
char ss[] = new char[s.length()];
bw.write(s);
bw.newLine();
s = br.readLine();
ss = s.toCharArray();
}
br.close();
bw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
import java.io.*;
import java.lang.*;public class Test {
public static void main(String[] args) {
try {
FileReader input = new FileReader("test1.txt");
BufferedReader br = new BufferedReader(input);
FileWriter output = new FileWriter("temp1.txt");
BufferedWriter bw = new BufferedWriter(output);
String s = br.readLine();
while ( s!=null ) {
char ss[] = new char[s.length()];
bw.write(s);
bw.newLine();
s = br.readLine();
ss = s.toCharArray();
}
br.close();
bw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
楼主【dlq45】截止到2008-07-07 09:46:53的历史汇总数据(不包括此帖):
发帖的总数量:2 发帖的总分数:0
结贴的总数量:0 结贴的总分数:0
无满意结贴数:0 无满意结贴分:0
未结的帖子数:2 未结的总分数:0
结贴的百分比:0.00 % 结分的百分比:---------------------
无满意结贴率:---------------------无满意结分率:---------------------
如何结贴请参考这里:http://topic.csdn.net/u/20080501/09/ef7ba1b3-6466-49f6-9d92-36fe6d471dd1.html
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;public class Test
{
public static void main(String[] args)
{
try
{
FileReader input = new FileReader("test1.txt");
BufferedReader br = new BufferedReader(input);
FileWriter output = new FileWriter("temp1.txt");
BufferedWriter bw = new BufferedWriter(output);
String s = br.readLine();
while(s != null)
{
//你这个ss根本主就没有用到,你要它干嘛??
char ss[] = new char[s.length()];
bw.write(s);
bw.newLine();
s = br.readLine();
//加一行判断不就行了
if(s != null)
{
ss = s.toCharArray();
}
} br.close();
bw.close();
}
catch(IOException e)
{
e.printStackTrace();
}
}
}
ss = s.toCharArray();
这两句顺序对调了一下
ss = s.toCharArray();
s = br.readLine();