diff --git a/src/main/java/internal/hw/crawler/commands/CrawlCommand.java b/src/main/java/internal/hw/crawler/commands/CrawlCommand.java
index 7e00e53..6012c03 100644
--- a/src/main/java/internal/hw/crawler/commands/CrawlCommand.java
+++ b/src/main/java/internal/hw/crawler/commands/CrawlCommand.java
@@ -10,6 +10,7 @@ import org.jsoup.nodes.Document;
 
 import java.net.URL;
 import java.util.List;
+import java.util.Objects;
 
 public class CrawlCommand implements Command {
     private final ArticleRepository repository;
@@ -41,13 +42,9 @@ public class CrawlCommand implements Command {
             return;
         }
 
-        Document doc = Jsoup.parse(url, 5000);
+        Document doc = Jsoup.connect(url.toString()).timeout(5000).get();
         List<Article> articles = strategy.parse(url, doc);
-        for (Article article : articles) {
-            if (article != null) {
-                repository.add(article);
-            }
-        }
+        articles.stream().filter(Objects::nonNull).forEach(repository::add);
         out.success(String.format("Crawled %d articles from %s", articles.size(), urlRaw));
     }
 }
diff --git a/src/main/java/internal/hw/crawler/commands/SaveCommand.java b/src/main/java/internal/hw/crawler/commands/SaveCommand.java
index 24b55d1..69f40f3 100644
--- a/src/main/java/internal/hw/crawler/commands/SaveCommand.java
+++ b/src/main/java/internal/hw/crawler/commands/SaveCommand.java
@@ -6,8 +6,10 @@ import internal.hw.crawler.repositories.ArticleRepository;
 import internal.hw.crawler.views.CommandOutput;
 
 import com.google.gson.JsonSyntaxException;
+
 import java.io.*;
 import java.util.*;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 
 public class SaveCommand implements Command {
@@ -30,11 +32,12 @@ public class SaveCommand implements Command {
         String filename = "articles.output.json";
 
         List<Article> articles = getExistingArticles(filename);
-        Map<String, Article> articleMap = articles.stream().collect(Collectors.toMap(this::articleMapId, it -> it));
+        Map<String, Article> articleMap = articles.stream()
+                .collect(Collectors.toMap(Article::computeUniqueKey, Function.identity()));
 
         // Update existing articles with new articles
         for (Article article : articleRepository.getAll()) {
-            articleMap.put(articleMapId(article), article);
+            articleMap.put(article.computeUniqueKey(), article);
         }
 
         Article[] articlesToSave = articleMap.values().toArray(new Article[0]);
@@ -45,10 +48,6 @@ public class SaveCommand implements Command {
         }
     }
 
-    private String articleMapId(Article article) {
-        return String.format("%s-%s", article.getSource(), article.getId());
-    }
-
     private List<Article> getExistingArticles(String filename) {
         try (BufferedReader reader = new BufferedReader(new FileReader(filename))) {
             Article[] articles = gson.fromJson(reader, Article[].class);
diff --git a/src/main/java/internal/hw/crawler/models/Article.java b/src/main/java/internal/hw/crawler/models/Article.java
index 124bb31..4d87f4a 100644
--- a/src/main/java/internal/hw/crawler/models/Article.java
+++ b/src/main/java/internal/hw/crawler/models/Article.java
@@ -59,6 +59,10 @@ public class Article {
         this.content = content;
     }
 
+    public String computeUniqueKey() {
+        return source + "-" + id;
+    }
+
     @Override
     public String toString() {
         return String.format("Article{%s (%s)}", title, url);
diff --git a/src/main/java/internal/hw/crawler/repositories/ArticleRepository.java b/src/main/java/internal/hw/crawler/repositories/ArticleRepository.java
index 79931cd..346fa51 100644
--- a/src/main/java/internal/hw/crawler/repositories/ArticleRepository.java
+++ b/src/main/java/internal/hw/crawler/repositories/ArticleRepository.java
@@ -2,22 +2,21 @@ package internal.hw.crawler.repositories;
 
 import internal.hw.crawler.models.Article;
 
-import java.util.ArrayList;
-import java.util.Collections;
+import java.util.LinkedHashMap;
 import java.util.List;
 
 public class ArticleRepository {
-    private final List<Article> articles = new ArrayList<>();
+    private final LinkedHashMap<String, Article> articles = new LinkedHashMap<>();
 
     public void add(Article article) {
         if (article == null) {
             throw new IllegalArgumentException("Article cannot be null");
         }
-        articles.add(article);
+        articles.put(article.computeUniqueKey(), article);
     }
 
     public List<Article> getAll() {
-        return Collections.unmodifiableList(articles);
+        return List.copyOf(articles.values());
     }
 
     public int size() {
diff --git a/src/main/java/internal/hw/crawler/strategies/crawl/IthomeCrawlStrategy.java b/src/main/java/internal/hw/crawler/strategies/crawl/IthomeCrawlStrategy.java
index 2bbc11a..6ad2eb5 100644
--- a/src/main/java/internal/hw/crawler/strategies/crawl/IthomeCrawlStrategy.java
+++ b/src/main/java/internal/hw/crawler/strategies/crawl/IthomeCrawlStrategy.java
@@ -8,6 +8,7 @@ import org.jsoup.select.Elements;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.net.URI;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.HashSet;
@@ -22,32 +23,39 @@ public class IthomeCrawlStrategy implements CrawlStrategy {
 
     @Override
     public boolean supports(URL url) {
-        return url.getHost().endsWith("ithome.com");
+        String host = url.getHost();
+        return host.equals("ithome.com") || host.endsWith(".ithome.com");
     }
 
     @Override
     public List<Article> parse(URL url, Document doc) throws CrawlException {
-        List<String> homepage = List.of("https://www.ithome.com", "https://ithome.com");
-        if (homepage.contains(url.toString())) {
-            // 传入的是首页，解析所有链接
+        if (isHomepage(url)) {
             return parseHomepage(doc);
         } else {
             return List.of(parseSingle(url, doc));
         }
     }
 
+    private boolean isHomepage(URL url) {
+        String path = url.getPath();
+        return (path == null || path.isEmpty() || path.equals("/"));
+    }
+
     private List<Article> parseHomepage(Document doc) {
         List<Article> articles = new ArrayList<>();
         Elements links = doc.getElementsByTag("a");
         for (Element link : links) {
-            String href = link.attr("href");
+            String href = link.absUrl("href");
+            if (href.isEmpty()) {
+                continue;
+            }
             Matcher matcher = idRegex.matcher(href);
             if (!matcher.find()) {
                 continue;
             }
 
             try {
-                URL articleUrl = new URL(href);
+                URL articleUrl = URI.create(href).toURL();
                 Document articleDoc = Jsoup.parse(articleUrl, 5000);
                 articles.add(parseSingle(articleUrl, articleDoc));
             } catch (Exception e) {
diff --git a/src/main/java/internal/hw/crawler/strategies/crawl/PeopleCnCrawlStrategy.java b/src/main/java/internal/hw/crawler/strategies/crawl/PeopleCnCrawlStrategy.java
index 0ce0f93..680e22a 100644
--- a/src/main/java/internal/hw/crawler/strategies/crawl/PeopleCnCrawlStrategy.java
+++ b/src/main/java/internal/hw/crawler/strategies/crawl/PeopleCnCrawlStrategy.java
@@ -8,6 +8,7 @@ import org.jsoup.select.Elements;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.net.URI;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.HashSet;
@@ -15,7 +16,6 @@ import java.util.List;
 import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
-import java.util.stream.Collectors;
 
 public class PeopleCnCrawlStrategy implements CrawlStrategy {
     private static final Logger log = LoggerFactory.getLogger(PeopleCnCrawlStrategy.class);
@@ -25,39 +25,48 @@ public class PeopleCnCrawlStrategy implements CrawlStrategy {
 
     @Override
     public boolean supports(URL url) {
+        String host = url.getHost();
         for (String domain : supportedDomains) {
-            if (url.getHost().endsWith(domain)) {
+            if (host.equals(domain) || host.endsWith("." + domain)) {
                 return true;
             }
         }
-
         return false;
     }
 
     @Override
     public List<Article> parse(URL url, Document doc) throws CrawlException {
-        List<String> homepage = supportedDomains.stream().map(it -> "https://www." + it).collect(Collectors.toList());
-
-        if (homepage.contains(url.toString())) {
-            // 传入的是首页，解析所有链接
+        if (isHomepage(url)) {
             return parseHomepage(doc);
         } else {
             return List.of(parseSingle(url, doc));
         }
     }
 
+    private boolean isHomepage(URL url) {
+        String host = url.getHost();
+        boolean matched = supportedDomains.stream()
+            .anyMatch(d -> host.equals(d) || host.endsWith("." + d));
+        if (!matched) return false;
+        String path = url.getPath();
+        return path == null || path.isEmpty() || path.equals("/");
+    }
+
     private List<Article> parseHomepage(Document doc) {
         List<Article> articles = new ArrayList<>();
         Elements links = doc.getElementsByTag("a");
         for (Element link : links) {
-            String href = link.attr("href");
+            String href = link.absUrl("href");
+            if (href.isEmpty()) {
+                continue;
+            }
             Matcher matcher = idRegex.matcher(href);
             if (!matcher.find()) {
                 continue;
             }
 
             try {
-                URL articleUrl = new URL(href);
+                URL articleUrl = URI.create(href).toURL();
                 Document articleDoc = Jsoup.parse(articleUrl, 5000);
                 articles.add(parseSingle(articleUrl, articleDoc));
             } catch (Exception e) {