暂时使用两种方式

src/main/java/com/github/hcsp/multithread/MultiThreadWordCount1.java

@@ -1,12 +1,56 @@
 package com.github.hcsp.multithread;
 
-import java.io.File;
-import java.util.List;
-import java.util.Map;
+import java.io.*;
+import java.util.*;
+import java.util.concurrent.*;
 
 public class MultiThreadWordCount1 {
     // 使用threadNum个线程，并发统计文件中各单词的数量
-    public static Map<String, Integer> count(int threadNum, List<File> files) {
-        return null;
+    public static Map<String, Integer> count(int threadNum, List<File> files) throws IOException, ExecutionException, InterruptedException {
+        ExecutorService threadPool = Executors.newFixedThreadPool(threadNum);
+        HashMap<String, Integer> resultMap = new HashMap<>();
+
+        for (File file : files) {
+            HashMap<String, Integer> OneFileResultMap = new HashMap<>();
+            BufferedReader reader = new BufferedReader(new FileReader(file));
+            List<Future<Map<String, Integer>>> futureList = new ArrayList<>();
+
+            for (int i = 0; i < 0; i++) {
+                Future<Map<String, Integer>> future = threadPool.submit(new Callable<Map<String, Integer>>() {
+                    @Override
+                    public Map<String, Integer> call() throws Exception {
+                        HashMap<String, Integer> oneLineMap = new HashMap<>();
+                        String line = null;
+                        while ((line = reader.readLine()) != null) {
+                            String[] words = line.split(" ");
+                            for (String word : words) {
+                                oneLineMap.put(word, oneLineMap.getOrDefault(word, 0) + 1);
+                            }
+                        }
+                        return oneLineMap;
+                    }
+                });
+                futureList.add(future);
+            }
+            mergeOneLineCountToOneFileCount(OneFileResultMap, futureList);
+            mergeOneLineCountToOneFileCountByMap(resultMap, OneFileResultMap);
+        }
+        return resultMap;
+    }
+
+    private static void mergeOneLineCountToOneFileCountByMap(Map<String, Integer> resultMap,
+                                                             Map<String, Integer> oneFileResultMap) {
+        Set<String> keys = oneFileResultMap.keySet();
+        for (String key : keys) {
+            resultMap.put(key, oneFileResultMap.getOrDefault(key, oneFileResultMap.get(key)));
+        }
+    }
+
+    private static void mergeOneLineCountToOneFileCount(HashMap<String, Integer> oneFileResultMap,
+                                                        List<Future<Map<String, Integer>>> futureList) throws ExecutionException, InterruptedException {
+        for (Future<Map<String, Integer>> futures : futureList) {
+            Map<String, Integer> oneLineResult = futures.get();
+            mergeOneLineCountToOneFileCountByMap(oneFileResultMap, oneLineResult);
+        }
     }
 }

src/main/java/com/github/hcsp/multithread/MultiThreadWordCount2.java

@@ -1,8 +1,55 @@
 package com.github.hcsp.multithread;
 
+import java.io.*;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
 public class MultiThreadWordCount2 {
-    // 使用threadNum个线程，并发统计文件中各单词的数量
-    //    public static Map<String, Integer> count(int threadNum, List<File> files) {
-    //        return null;
-    //    }
+
+    //使用threadNum个线程，并发统计文件中各单词的数量
+    public static Map<String, Integer> count(int threadNum, List<File> files) throws IOException {
+        HashMap<String, Integer> resultMap = new HashMap<>();
+        for (File file : files) {
+            BufferedReader reader = new BufferedReader(new FileReader(file));
+            Object lock = new Object();
+            HashMap<String, Integer> oneFileResultMap = new HashMap<>();
+            for (int i = 0; i < 9; i++) {
+                new Thread(() -> {
+                    synchronized (lock) {
+                        String line = null;
+                        while (true) {
+                            try {
+                                if (!((line = reader.readLine()) != null)) {
+                                    break;
+                                }
+                            } catch (IOException e) {
+                                e.printStackTrace();
+                            }
+                            String[] words = line.split(" ");
+                            for (String word : words) {
+                                if (oneFileResultMap.containsKey(word)) {
+                                    oneFileResultMap.put(word, oneFileResultMap.get(word) + 1);
+                                } else {
+                                    oneFileResultMap.put(word, 1);
+                                }
+                            }
+                        }
+                    }
+                });
+            }
+            mergeOneLineCountToOneFileCountByMap(resultMap, oneFileResultMap);
+        }
+        return resultMap;
+    }
+
+
+    private static void mergeOneLineCountToOneFileCountByMap(Map<String, Integer> resultMap,
+                                                             Map<String, Integer> oneFileResultMap) {
+        Set<String> keys = oneFileResultMap.keySet();
+        for (String key : keys) {
+            resultMap.put(key, oneFileResultMap.getOrDefault(key, oneFileResultMap.get(key)));
+        }
+    }
 }