课堂测试2

输出单个文件中前N个最常出现的英语单词

package words;
import java.io.*;
import java.util.Scanner;
public class boter
{
private static String str="";
private static Scanner sc=new Scanner(System.in);
private static BufferedReader br=null;
private static String a[]=new String[1000000];
private static String c[]=new String[10000000];
private static int b[]=new int[1000000];
private static int l=0;
private static int l1=0;
private static int n=0;
private static int j=0;
//private static Boolean false;
public static void cunfang() throws IOException
{//将单词存到数组a

while(str!=null)
{
int i=0;
str=str.toLowerCase(); //把大写改成小写
for(i=0;i<str.length();i++)
{
if((str.charAt(i)>96&&str.charAt(i)<123))
{
a[j]=a[j]+str.charAt(i);
}
if(str.charAt(i)==' '||str.charAt(i)==','||str.charAt(i)=='.')
{
if(!a[j].equals(""))
{
j=j+1;
a[j]="";
}
}

}
str=br.readLine();
}
l=j;

}
public static void show()
{//显示
for(int k=0;k<n;k++)
{
System.out.println(c[k]+" "+b[k]);
}
}
public static void paixu()
{//排序
int t3=0;
int t2=0;
String sr="";
for(int i=0;i<l-1;i++)
{
t3=i;
for(int j=i+1;j<l1;j++)
{
if(b[t3]<b[j])
{
t3=j;
}
}
if(t3!=i)
{
t2=b[i];
b[i]=b[t3];
b[t3]=t2;
sr=c[i];
c[i]=c[t3];
c[t3]=sr;
}
}
}
public static void quchong()
{//去重
for(int k=0;k<l;k++)
{
b[k]=0;
}
c[0]=a[0];
int tt=1;
Boolean rt=true;

for(int i=1;i<l;i++)
{
rt=false;
for(int j=0;j<tt;j++)
{
if(a[i].equals(c[j]))
{
rt=true;
break;
}
}
if(!rt)
{
c[tt]=a[i];
tt++;
}
}

l1=tt;
for(int i=0;i<l1;i++)
{
for(int j=0;j<l;j++)
{
if(c[i].equals(a[j]))
{
b[i]++;
}
}
}
}
public static void Readfile()
{
File file=new File("D:\poter.txt");
try
{
InputStreamReader read = new InputStreamReader(new FileInputStream(file),"UTF-8");//InputStreamReader实现从字节流到字符流的转换
br=new BufferedReader(read);
str=br.readLine();
cunfang();
br.close();
read.close();
}
catch(IOException e)
{
System.out.println("读取失败！");
e.printStackTrace();
}
}

public static void Writefile() throws IOException
{
File file=new File("D:\poter.txt");
if(!file.exists())
file.createNewFile();
FileWriter write = new FileWriter(file,true);
BufferedWriter out=new BufferedWriter(write);
for(int i=0;i<n;i++)
{
StringBuffer sb=new StringBuffer();
out.write("这是第"+(i+1)+"个: ");
out.write(c[i]+" "+b[i]);
out.write(" ");
}
out.close();
}
public static void main(String[] args) throws IOException
{
System.out.println("请输入您要统计前几个最常出现的单词：");
n=sc.nextInt();
a[0]="";
Readfile();
quchong();
paixu();
show();
Writefile();

}

}

 设置数组，将各个字母存放其中，再将大写字母进行转换，之后排序，去重，输出