Add query result set limit. (#2459)

* Optimize PropertyUtils instantiation.

* Fix info error.

* Add query result set limit.

* fix code smell
Co-authored-by: Ndailidong <dailidong66@gmail.com>
Co-authored-by: Nqiaozhanwei <qiaozhanwei@outlook.com>

dolphinscheduler-server/src/main/java/org/apache/dolphinscheduler/server/worker/task/sql/SqlTask.java

@@ -16,7 +16,6 @@
  */
 package org.apache.dolphinscheduler.server.worker.task.sql;
 
-import com.alibaba.fastjson.JSON;
 import com.alibaba.fastjson.JSONArray;
 import com.alibaba.fastjson.JSONObject;
 import com.alibaba.fastjson.serializer.SerializerFeature;
@@ -24,7 +23,6 @@ import org.apache.commons.lang.StringUtils;
 import org.apache.dolphinscheduler.alert.utils.MailUtils;
 import org.apache.dolphinscheduler.common.Constants;
 import org.apache.dolphinscheduler.common.enums.*;
-import org.apache.dolphinscheduler.common.enums.AuthorizationType;
 import org.apache.dolphinscheduler.common.enums.DbType;
 import org.apache.dolphinscheduler.common.enums.ShowType;
 import org.apache.dolphinscheduler.common.enums.TaskTimeoutStrategy;
@@ -37,7 +35,6 @@ import org.apache.dolphinscheduler.common.utils.*;
 import org.apache.dolphinscheduler.dao.AlertDao;
 import org.apache.dolphinscheduler.dao.datasource.BaseDataSource;
 import org.apache.dolphinscheduler.dao.datasource.DataSourceFactory;
-import org.apache.dolphinscheduler.dao.entity.ProcessInstance;
 import org.apache.dolphinscheduler.dao.entity.User;
 import org.apache.dolphinscheduler.server.entity.SQLTaskExecutionContext;
 import org.apache.dolphinscheduler.server.entity.TaskExecutionContext;
@@ -78,6 +75,10 @@ public class SqlTask extends AbstractTask {
      */
     private TaskExecutionContext taskExecutionContext;
 
+    /**
+     * default query sql limit
+     */
+    private static final int LIMIT = 10000;
 
     public SqlTask(TaskExecutionContext taskExecutionContext, Logger logger) {
         super(taskExecutionContext, logger);
@@ -257,12 +258,15 @@ public class SqlTask extends AbstractTask {
         ResultSetMetaData md = resultSet.getMetaData();
         int num = md.getColumnCount();
 
-        while (resultSet.next()) {
+        int rowCount = 0;
+
+        while (rowCount < LIMIT && resultSet.next()) {
             JSONObject mapOfColValues = new JSONObject(true);
             for (int i = 1; i <= num; i++) {
                 mapOfColValues.put(md.getColumnName(i), resultSet.getObject(i));
             }
             resultJSONArray.add(mapOfColValues);
+            rowCount++;
         }
         logger.debug("execute sql : {}", JSONObject.toJSONString(resultJSONArray, SerializerFeature.WriteMapNullValue));