JAVA读取文件对比

package filecollector;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.RandomAccessFile;
import java.util.Stack;

public class FileRead {
?public static void main(String[] args) {
??bufReader();
??randomReader();
?}
?public static void bufReader(){
??File file= new File("e:/test.txt");
??Stack st = new Stack();
??long currpos=0;
??long startTime=System.currentTimeMillis();
??try {
????FileReader fileReader = new FileReader(file);
????BufferedReader read = new BufferedReader(fileReader);
????String line = null;??
????while ((line = read.readLine()) != null) {?????
??????if(line.startsWith("IE6")){
???????st.push(currpos);
??????}
??????currpos+=(line.length()+2);
?????}
????if(st.size()>20000){
?????currpos=Long.valueOf(st.get(st.size()-20).toString());
????}else{
?????currpos=0;
????}
???} catch (Exception e) {
????e.printStackTrace();
???}
??System.out.println(currpos);
??FileReader fileReader;
??try {
???fileReader = new FileReader(file);
???BufferedReader read = new BufferedReader(fileReader);
???read.skip(currpos);
???System.out.println(read.readLine());
??} catch (Exception e) {
???// TODO Auto-generated catch block
???e.printStackTrace();
??}
??System.out.println(System.currentTimeMillis()-startTime);
?}
?public static void randomReader(){
??File file= new File("e:/test.txt");
??long startTime=System.currentTimeMillis();
??int count=0;
??String line=null;
??try {
????RandomAccessFile randomReader = new RandomAccessFile(file, "r");
????long filelen=randomReader.length()-1;
????while(filelen>0&&count<20000){
??????randomReader.seek(filelen);
??????char c=(char)randomReader.read();
??????if(c =='\r'||c =='\n'){
???????line = randomReader.readLine();
???????if(line!=null&&line.startsWith("IE6")){
????????count++;
???????}
??????}
??????filelen--;
????}
????System.out.println(filelen);
????System.out.println(line);
???} catch (Exception e) {
????e.printStackTrace();
???}
??System.out.println(System.currentTimeMillis()-startTime);
?}
?}

如果遇到随机读取文件，使用时最好先比较一下计算时间