这是一项正在进行的工作,但我想知道如何访问特定文件。 我的主要方法是构造一个新的FileInputStream,并以新文件作为参数。然后,我应该调用getCounts方法接受FileInputStream对象来返回某种类型的map。在getCounts方法中,我无法完成此操作,因为我必须能够访问其中的文件,而FileInputStream似乎没有它的访问器。换句话说,如何在getCounts方法中访问用于构造作为参数进入getCounts方法的FileInputStream对象的文件?最终,我应该使用地图的键/值来获得文本文件中最重复的字符。感谢。
这是我的代码:
import java.util.*;
import java.io.*;
public class test2 {
public static void main(String[] q) throws FileNotFoundException {
// This is for the character mapping
Scanner console = new Scanner(System.in);
System.out.println("Count characters of which file? ");
FileInputStream output = new FileInputStream(new File(console.nextLine()));
Map<Character, Integer> results = getCounts(output);
// do stuff with this map later on...
}
// character counting method (WIP)
public static Map<Character, Integer> getCounts(FileInputStream input) {
Map<Character, Integer> output = new TreeMap<Character, Integer>(); // treemap keeps keys in sorted order (chars alphabetized)
// Problem here: need to access the file object that was instiantiated
byte[] fileContent = new byte[(int) file.length()]; // puts all the bytes from file into byte[] to process
input.read(fileContent);
String test = new String(fileContent);
// missing stuff here; use map to map keys as characters and occurrences as values.
return output;
}
}
答案 0 :(得分:2)
如果您要使用FileInputStream,则需要循环,执行多次读取
byte[] fileContent = new byte [1024];
while ((input.read (fileContent) != -1) {
// save fileContent somewhere
// e.g.
arrlist.add (new String (fileContent));
}
答案 1 :(得分:1)
理想情况下,我会将length
作为参数传递给getCounts()
,但由于您不允许这样做,您可以将文件长度保存为类静态参数:
private static long length;
public static void main(String[] q) throws IOException {
// This is for the character mapping
Scanner console = new Scanner(System.in);
System.out.println("Count characters of which file? ");
File file = new File(console.nextLine());
FileInputStream output = new FileInputStream(file);
length = file.length();
Map<Character, Integer> results = getCounts(output);
// do stuff with this map later on...
}
// character counting method (WIP)
public static Map<Character, Integer> getCounts(FileInputStream input) throws IOException {
Map<Character, Integer> output = new TreeMap<Character, Integer>(); // treemap keeps keys in sorted order (chars alphabetized)
// Problem here: need to access the file object that was instantiated
byte[] fileContent = new byte[(int) length]; // puts all the bytes from file into byte[] to process
input.read(fileContent);
String test = new String(fileContent);
System.out.println("test = " + test);
// missing stuff here; use map to map keys as characters and occurrences as values.
return output;
}