fix(sj_1.1.0-beta2): 修复reduce分片算法错误问题

snail-job-server/snail-job-server-job-task/src/main/java/com/aizuda/snailjob/server/job/task/support/generator/task/MapReduceTaskGenerator.java

@@ -136,10 +136,8 @@ public class MapReduceTaskGenerator extends AbstractJobTaskGenerator {
         }
 
         // 这里需要判断是否是map
-        // 平均分配map集合, 若reduceParallel > allMapJobTasks.size(), 则取allMapJobTasks.size()作为分片数
         List<String> allMapJobTasks = StreamUtils.toList(jobTasks, JobTask::getResultMessage);
-        int size = (allMapJobTasks.size() + reduceParallel - 1) / reduceParallel;
+        List<List<String>> partition = averageAlgorithm(allMapJobTasks, reduceParallel);
-        List<List<String>> partition = Lists.partition(allMapJobTasks, size);
 
         jobTasks = new ArrayList<>(partition.size());
         final List<JobTask> finalJobTasks = jobTasks;
@@ -238,4 +236,28 @@ public class MapReduceTaskGenerator extends AbstractJobTaskGenerator {
 
         return jobTasks;
     }
+    private List<List<String>> averageAlgorithm(List<String> allMapJobTasks, int shard) {
+
+        // 最多分片数为allMapJobTasks.size()
+        shard = Math.min(allMapJobTasks.size(), shard);
+        int totalSize = allMapJobTasks.size();
+        List<Integer> partitionSizes = new ArrayList<>();
+        int quotient = totalSize / shard;
+        int remainder = totalSize % shard;
+
+        for (int i = 0; i < shard; i++) {
+            partitionSizes.add(quotient + (i < remainder ? 1 : 0));
+        }
+
+        List<List<String>> partitions = new ArrayList<>();
+        int currentIndex = 0;
+
+        for (int size : partitionSizes) {
+            int endIndex = Math.min(currentIndex + size, totalSize);
+            partitions.add(new ArrayList<>(allMapJobTasks.subList(currentIndex, endIndex)));
+            currentIndex = endIndex;
+        }
+
+        return partitions;
+    }
 }