Question

下面java程序哪出错了？

程序功能：统计文件中各个字符串（ip地址）出现的次数
代码如下：import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;

public class IpDistribution {

public static void main(String[] args) {
BufferedReader br1 = null;
BufferedReader br2 = null;
List<String> ips = new ArrayList<String>();
List<Integer> cishu = new ArrayList<Integer>();
try {
String line = null;
String temp = null;
String xx = null;
int m = 0;
br1 = new BufferedReader(new FileReader("F:\\guyi\\test.ips"));
br2 = new BufferedReader(new FileReader("F:\\guyi\\test.ips"));

while ((xx = br1.readLine()) != null) {
temp = xx;
if (!ips.contains(xx)) {
ips.add(temp);
while ((line = br2.readLine()) != null) {
if (line.matches(temp)) {
m++;
}
}
cishu.add(m);
m=0;
}

}
for (int i = 0; i < cishu.size(); i++) {
System.out.println(cishu.get(i));
}

} catch (IOException e) {
e.printStackTrace();
}
}

}
test.ips文件如下：
202.195.120.2
202.195.120.5
202.195.120.4
202.195.120.2
202.195.120.2
202.195.120.5
202.195.120.4
202.195.120.4
上面程序结果为3 0 0，请问怎么修改 使得程序结果变成3 2 3

Answer 1

容器改用map，只写main方法部分：

public static void main(String[] args) {
BufferedReader br1 = null;
Map<String, Integer> ipCount = new HashMap<String, Integer>();

try {
String line = null;
Integer count = null;
br1 = new BufferedReader(new FileReader("F:\\guyi\\test.ips"));
//计数
while ((line = br1.readLine()) != null) {
count = ipCount.get(line);
ipCount.put(line, count==null ? count : count++);
}
//遍历ipCount map
Set<Entry<String, Integer>> ips = ipCount.entrySet();
for(Entry<String, Integer> ip : ips)
System.out.println(String.format("%s ---> %d", ip.getKey(), ip.getValue().intValue()));
} catch (IOException e) {
e.printStackTrace();
}
}

Answer 2

br1 = new BufferedReader(new FileReader("F:\\guyi\\test.ips"));
把它改成br1 = new BufferedReader(shuty FileReader("F:\\bbs\\test.hti
"));就行了，如果还不可以，我不知道了。

Answer 3

把IP地址202.195.120.5改为202.199.156这是我家的，不知道对你合不合适。
或者添加System：may be（System.out.println(cishu.get(i));可能行，但是要小心导致电脑奔溃额。

Answer 4

你把br2 = new BufferedReader(new FileReader("C:\\test.ips"));剪切到ips.add(temp);下面试试吧；第一次循环内部while已经把文件读到结尾了,而你内部while判断条件又是(line = br2.readLine()) != null,所以之后内部while都跳过了