Iterator接口包装

Iterator<T>接口可以被包装，方便操作。

import java.io.*;

import java.util.*;

public class FileUtil{

public static Iterator<String> getFileIterator(String filename)

throws IOException{

final FileReader fr = new FileReader(new File(filename));

final BufferedReader br = new BufferedReader(fr);

return new Iterator<String>(){

String line = getLine(); 

public boolean hasNext() {

return line != null;

}

 

public String next() {

String res = line;

line = getLine();

return res;

}

 

public void remove() {

throw new UnsupportedOperationException();

}

private String getLine(){

String line;

try{

line = br.readLine();

}catch(IOException e){

line = null;

}

return line;

}

};

}

public static void main(String[] argv){

Iterator<String> iString = null;

try {

iString = FileUtil.getFileIterator("zhanglizhe.txt");

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

while(iString!=null && iString.hasNext())

System.out.println(iString.next());

}

}