package com.tl.utils;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;

public class FileOperator {
    public static String readLocalFile(String filePath){
        BufferedReader br=null;
        StringBuilder stringBuilder=new StringBuilder();
        try {
            FileInputStream fis=new FileInputStream(filePath);
            InputStreamReader isr=new InputStreamReader(fis,"utf-8");
            br=new BufferedReader(isr);
            String tempLine=null;
            //定义行计数器
            int line_counter=0;
            while((tempLine=br.readLine())!=null){
                //去除左右空格
                tempLine=tempLine.trim();
                //实现逻辑：第二行才开始每一行的行首加换行。
                if(line_counter>0){
                    stringBuilder.append("\n");
                }
                stringBuilder.append(tempLine);
                line_counter++;
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally{
            if(br!=null){
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return stringBuilder.toString();
    }
    public static void main(String[] args) {
        String filePath="student.txt";
        String result=readLocalFile(filePath);
        System.out.println(result);
    }
}