修bug

src/main/java/com/bao/dating/handler/ListToVarcharTypeHandler.java

@@ -6,10 +6,7 @@ import org.apache.ibatis.type.MappedJdbcTypes;
 import org.apache.ibatis.type.MappedTypes;
 import org.apache.ibatis.type.TypeHandler;
 
-import java.sql.CallableStatement;
-import java.sql.PreparedStatement;
-import java.sql.ResultSet;
-import java.sql.SQLException;
+import java.sql.*;
 import java.util.Arrays;
 import java.util.List;
 
@@ -22,6 +19,11 @@ import java.util.List;
 public class ListToVarcharTypeHandler implements TypeHandler<List<String>> {
     @Override
     public void setParameter(PreparedStatement preparedStatement, int i, List<String> strings, JdbcType jdbcType) throws SQLException {
+        // 允许 null
+        if (strings == null || strings.isEmpty()) {
+            preparedStatement.setNull(i, Types.VARCHAR);
+            return;
+        }
         // 遍历List类型的入参，拼装为String类型，使用Statement对象插入数据库
         StringBuffer sb = new StringBuffer();
         for (int j = 0; j < strings.size(); j++) {