使用BufferedReader读取TXT文件中数值,并输出最大值

BufferedReader(Reader in)
BufferedReader(Reader in, int size)
 
void     close()
void     mark(int markLimit)
boolean  markSupported()
int      read()
int      read(char[] buffer, int offset, int length)
String   readLine()
boolean  ready()
void     reset()
long     skip(long charCount)

String str  = null;
br=new BufferedReader(new FileReader(fileName));
while(br.read()!=-1){
  str = buf.readLine()); 
}

   for(int i=0;i<s2.length;i++){
	  a[i]= Integer.valueOf(s2[i]);
    }

package test; 
import java.io.*; 
public class testtwo {
		public static void main(String[] args) throws IOException {
	       try {
	    	   //1.打开文件
	    	   FileReader fr=new FileReader("test.txt");
	    	   //2.使用BufferedReader读取
	    	   BufferedReader br=new BufferedReader(fr);
	    	   //保存数据
	    	   String message = "";  
	    	   String line = null;  
	    	   while((line = br.readLine()) != null) {
	    		   message = message+" "+line;  
	    	   }
	    	   //去掉两端空格
	    	   message = message.trim();
                   //转化成数组
	    	   String s2[]=message.split(" ");
	    	   int a[]=new int[message.length()];
	    	   for(int i=0;i<s2.length;i++){
	    		    a[i]= Integer.valueOf(s2[i]);
	    	   }
	    	   //比较最大值
	    	   int max=a[0];
	    	   for(int j=1;j<a.length;j++){
	    		   if(max<a[j]){
	    			   max=a[j];
	    		   }
	    	   }
	    	   System.out.println("最大值为"+max);
	    	   //4.关闭文件
		       br.close();
	    	   fr.close();	    	   
	       } catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} 
	 } 
}