Question

我有一个文本文件，它看起来像这样：

gui awtui   swingui
swingui runner  extensions
textui  runner  framework
awtui   runner
runner  framework
extensions  framework

它们由标签分隔

我使用哈希映射存储它们，键是第一行，值是该行中的其余字符，例如： key = gui value = atwui swingui

因此，我使用了一个密钥，多值哈希映射来实现这一点，这就是我到目前为止所做的。

import java.util.*;
import java.io.*;

public class PackageAnalyser {

public static void main(String[] args) throws IOException{
    HashMap<String, List<String>> dependencies = new HashMap<String, List<String>>();
        List<String> pack = new ArrayList<String>();    
        try (Scanner in = new Scanner(new File(args[0]))){
            //String line = null;
            while ((in.hasNext() )){
                String [] packs = in.nextLine().split("\t");
                for (int i = 0; i < packs.length; i++){
                    pack.add(packs[i]);
                    Arrays.sort(packs);
                } 
                dependencies.put(packs[0], pack);
                }

            }catch (IOException ex){
                System.err.println(ex);
            } finally {
        }System.out.println(dependencies);
    }
}

在多次尝试修改代码之后，这就是我运行时输出的样子

`{awtui = [awtui, swingui, runner, swingui, runner, textui, runner, framework, framework], framework=[awtui, swingui, runner, swingui, textui, runner, framework, framework], extensions=[awtui, swingui, runner, swingui, runner, textui, runner, framework, framework]}

我想要的输出是：

{gui = [awtui, swingui], swingui = [runner, extensions], textui =[runner, framework], awtui = [runner], runner = [framework], extensions = [framework]}

如图所示，我正在阅读文本文件，我希望显示上面的输出显示。请帮忙。

Answer 1

public class PackageAnalyser {

    public static void main(String[] args) throws IOException {
        HashMap<String, SortedSet<String>> dependencies = new HashMap<String, SortedSet<String>>();

        try (Scanner in = new Scanner(new File(args[0]))) {
            while ((in.hasNext())) {
                String[] packs = in.nextLine().split("\\s");
                String key = packs[0];

                SortedSet<String> deps = dependencies.get(key);
                if (deps == null) {
                    deps = new TreeSet<String>();
                    dependencies.put(key, deps);
                }

                for (int i = 1; i < packs.length; i++) {
                    if (!packs[i].equals("")) {
                        deps.add(packs[i]);                 
                    }
                }                
            }

        } catch (IOException ex) {
            System.err.println(ex);
        } finally {
        }
        System.out.println(dependencies);
    }
}

给出{extensions=[framework], textui=[framework, runner], gui=[awtui, swingui], swingui=[extensions, runner], awtui=[runner], runner=[framework]}

如果您想保留插入顺序，可以使用LinkedHashMap代替普通HashMap

Answer 2

首先，您要将整个列表添加到您的值中，而不是丢弃第一个值。

其次，抛弃它，或移动它。你正在对它进行排序，然后存储第一个值。这可能会弄乱您的订单并使用错误的密钥。

最后，它似乎从未被清除。在每个循环之后，pack必须是新的arraylist，或者清除它的值

Answer 3

也许，您试图排序以保留读取顺序。但这是一段相对较短的代码：

package com.demo;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Scanner;

public class PackageAnalyser {

    public static void main(String[] args){

        Scanner scanner = null;

        try {
            scanner = new Scanner(new File(args[0]));
            String line = null;
            String[] lineParts = null;

            HashMap<String, List<String>> dependencies = new LinkedHashMap<String, List<String>>();

            while(scanner.hasNextLine()){
                line = scanner.nextLine();
                lineParts = line.split("\\s+");

                dependencies.put(lineParts[0], Arrays.asList(Arrays.copyOfRange(lineParts, 1, lineParts.length)));
            }

            System.out.println(dependencies);

        } catch (FileNotFoundException e) {
            System.err.println(e.getMessage());
        } finally {
            scanner.close();
        }
    }
}

给出

{gui = [awtui，swingui]，swingui = [runner，extensions]，textui = [runner，框架]，awtui = [亚军]，亚军= [框架]，扩展= [框架]}

尝试读取txt文件并将其存储在多值哈希映射中的数组列表中

3 个答案: