Java BufferedReader文件读取 带缓冲区的字符流

package org.jimmy.autosearch2019.test;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;

public class Test20190412 {

    public static void main(String[] args) {

    }

    public static ArrayList<String> readFile(int cacheLength, String filePath, String codedFormat) throws Exception {
        FileInputStream fis = new FileInputStream(filePath);
        BufferedReader br = new BufferedReader(new InputStreamReader(fis, codedFormat));
        int fileLength = fis.available();
        if(fileLength < cacheLength) {
            cacheLength = fileLength;
        }
        int len = cacheLength;
        char[] chars = new char[cacheLength];
        while((len = br.read(chars, 0, len)) != -1) {
            String text = new String(chars);
            System.out.println(text);
        }
        br.close();
        fis.close();
        return null;
    }

}

直接上代码.