代码优化

ruoyi-modules/ruoyi-server/src/main/java/org/dromara/server/service/impl/CrmContractServiceImpl.java

 package org.dromara.server.service.impl;
 
 import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
+import com.baomidou.mybatisplus.core.toolkit.CollectionUtils;
 import com.baomidou.mybatisplus.core.toolkit.Wrappers;
 import lombok.RequiredArgsConstructor;
 import org.dromara.common.core.utils.StringUtils;
@@ -57,7 +58,7 @@ public class CrmContractServiceImpl extends AbstractBaseService<CrmContractVo, C
                 .setUserId(LoginHelper.getUserId())
             ));
 
-        if (list.size() > 0) {
+        if (CollectionUtils.isNotEmpty(list)) {
             throw new RuntimeException("联系人已存在");
         }