Generic method return type

Here's the Animal class: public class Animal{ private Map<String,Animal> friends =new HashMap<String,Animal>(); public void addFriend(String name,Animal animal){ friends.put(name,animal);} public Animal callFriend(String name){return friends.g…

一种封装Retrofit的方法，可以自动解析Gson，回避Method return type must not include a type variable or wildcard: retrofit2.Call<T>的问题

封装目的:屏蔽底层实现,提供统一接口,并支持Gson自动转化最初封装: //请求方法 interface RequestListener { interface PostListener { @POST fun <T>call(@Url url: String, @Body t:Any) : Call<T> } } //封装请求 class NetUtils private constructor(retrofit: Retrofit){ private val mRetrofi…

delete attempted to return null from a method with a primitive return type (int)

今天被自己给蠢死了今天在代码中遇到这个错误, 百度翻译一下:映射方法,从一org.system.mapper.child.chmorganizationexaminationmapper.delete返回零作为一个原始的方法的返回类型(int). org.apache.ibatis.binding.BindingException: Mapper method 'org.system.mapper.child.ChmOrganizationExaminationMapper.delete at…

rg.apache.ibatis.binding.BindingException: Mapper method 'com.dao.Cameao.getOnlineDayRation attempted to return null from a method with a primitive return type (float)

本文为博主原创,未经允许不得转载: 异常展示如下: org.apache.ibatis.binding.BindingException: Mapper method 'com.dao.Cameao.getOnlineDayRation attempted to return null from a method with a primitive return type (float). at org.apache.ibatis.binding.MapperMethod.execute(Mapp…

mysql查询null异常:attempted to return null from a method with a primitive return type

select sum(deposit_amount)from tb_commission_ib_day mysql查询时报异常: attempted to return null from a method with a primitive return type 是因为查询时结果是 null, 需要给默认值 select IFNULL(sum(deposit_amount),0) from tb_commission_ib_day…

org.apache.ibatis.binding.BindingException: Mapper method 'attempted to return null from a method with a primitive return type (long).

一.问题描述今天发现测试环境报出来一个数据库相关的错误 org.apache.ibatis.binding.BindingException: Mapper method 'attempted to return null from a method with a primitive return type (long). 二.问题根源经过查询后发现,Mybatis 在查询id信息的时候返回类型为long ,没有留意long和Long的区别. Long是long的包装类,long是基本数据类…

[TypeScript] Infer the Return Type of a Generic Function Type Parameter

When working with conditionals types, within the “extends” expression, we can use the “infer” keyword to either get the type of the elements of an array, or even to get the return type of a function. We can use this to build a “FnReturnType” type, th…

attempted to return null from a method with a primitive return type (int).

java接口文件 package com.cyb.ms.mapper; import org.apache.ibatis.annotations.Param; public interface AccountMapper { void update(@Param("name") String name, @Param("money") int money); int queryMoney(String name); } xml文件 <?xml version=…

Bean property ‘mapperHelper’ is not writable or has an invalid setter method. Does the parameter type of the setter match the return type of the getter?

spring boot 报错: Caused by: org.springframework.beans.NotWritablePropertyException: Invalid property ‘mapperHelper’ of bean class [org.mybatis.spring.mapper.MapperFactoryBean]: Bean property ‘mapperHelper’ is not writable or has an invalid setter meth…

Mapper method 'com.xxxx.other.dao.MyDao.getNo attempted to return null from a method with a primitive return type (int)

使用myBatis调用存储过程的返回值,提示错误信息: org.apache.ibatis.binding.BindingException: Mapper method 'com.xxxx.other.dao.MyDao.getNo attempted to return null from a method with a primitive return type (int). 先查mysql监控语句,发现存储过程调用正常,也得到了返回值,继续查对应的文件存储过程: CREATE PRO…

mybatis查询时使用基本数据类型接收报错-attempted to return null from a method with a primitive return type (int)

一.问题由来自己在查看日志时发现日志中打印了一行错误信息为: 组装已经放养的宠物数据异常--->Mapper method 'applets.user.mapper.xxxMapper.xxxmyRank attempted to return null from a method with a primitive return type (int). 意思很好理解,就是在某个mapper文件中的xxxmyRank 这个查询方法返回一个null,可是却需要返回一个int类型的数,因此报错. 二…

instance method '*****' not found (return type defaults to 'id')

博文转载至 http://blog.csdn.net/cerastes/article/details/38025801 return type defaultsnot foundiOSwarning 在一个类里面引用另外一个类的实例方法,警告方法没有找到. 原因.h文件没有应用,只在头文件中申明了@class #import相应的.h文件就可以…

c++11: trailing return type in functions（函数返回类型后置）

In C++03, the return type of a function template cannot be generalized if the return type relies on those of the template arguments. Here is an example, mul(T a, T b) is a function template that calculates the product of a and b. Arguments a and b ar…

solr6.3 + Hbase Indexer使用MR创建索引，错误Bad return type

使用solr6.3 + Hbase Indexer ,通过Hbase-indexer从Hbase建立索引到solr中,进行全文搜索. 两种实现方式:① 开启hbase-indexer进行实时同步新数据 ② 使用MapReduce给存量数据创建索引. 在用MR跑索引的过程中,碰到问题:Mapper数总共35个,但failed了4个,成功也显示35个,整个JOB显示成功success.但是最终索引总数,比hbase表中数据要少,查看MR的counter,有插入错误的情况,如下所示: DirectSo…

无法将类型“System.Collections.Generic.List<anonymous type:string ClassID,string ClsssName>”隐式转换为“System.Collections.Generic.List<Ecology.Model.EnergyFlowGraph>”

无法将类型“System.Collections.Generic.List<anonymous type:string ClassID,string ClsssName>”隐式转换为“System.Collections.Generic.List<Ecology.Model.EnergyFlowGraph>” 一.EF应用中,常见类型转换问题解决方案 public List<EnergyFlowGraph> GetData() { var data = db.Energ…

Does the parameter type of the setter match the return type of the getter?

JDK 1.8, dubbo-admin版本是2.5.4-SNAPSHOT,tomcat8.5启动,报错: ERROR context.ContextLoader - Context initialization failed org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'uriBrokerService': Cannot create inner bean '(in…

使用JFinal的第一个项目出现的问题（The return type is incompatible with JspSourceDependent.getDependants()）

四月 08, 2016 4:35:34 下午 org.apache.catalina.core.ApplicationDispatcher invoke严重: Servlet.service() for servlet jsp threw exceptionorg.apache.jasper.JasperException: Unable to compile class for JSP: An error occurred at line: [39] in the generated java…

PHP报错: Can't use method return value in write context

$dp_id = $this->getParam('dpId'); if(!empty($this->getParam('dpId'))) { $this->smarty->assign('developer', get_developers($this->getParam('dpId'))); } 以上PHP会报错: Can't use method return value in write context 解决办法为分开写 $dp_id = $this->getP…

The method of type must override a superclass method

导入android项目时,报The method of type must override asuperclass method 一堆错误, 解决方法: 将编译的jdk与使用的jdk版本一致即可.…

The method of type must override a superclass method解决方式

工程导入myeclipse时,出现问题提示:The method of type must override asuperclass? annotation:@Override的原因查阅了一下资料,发现说在jdk1.5下要使用@Override 这个annotation 必须保证被标注方法来源于class 而不是interface, 但我检查过,发现自己的jdk确实是1.6版本啊. 最后发现,即使自己的jdk是1.6,还需要修改myeclipse里面的编译jdk版本,从5.0改成6.0,要不…

解决C语言程序报错：return type defaults to‘int’

下面是通过自定义一个函数printN,之后在main函数中调用printN,使得可以通过输入整数N,将从1到N的全部整数都打印出来的程序. 但是在编译过程中却报错: return type defaults to 'int' 产生报错的原因: printN的默认返回值类型是int类型的,这样调用printN函数的main函数就需要定义为: int main() 而不是: main() 产生报错的程序: #include<stdio.h> //自定义printN函数 void printN (i…

【c++错误】类的语法错误 error c2533：constructors not allowed a return type（构造函数不允许返回一个类型）

今天编写类的程序的时候不小心把类后的分号忘写了,就出现上面的错误提示. 顺便复习下类的正确格式: class 类名 { public: //习惯上将公有类型放在前面,便于阅读 ……(外部接口) protected: …… (保护型成员) private: ……(私有成员) }; //这里的分号千万不能忘写,不然会出现错误error: 2533:constructors not allowed a return type…

Caused by: java.lang.IllegalArgumentException: Modifying queries can only use void or int/Integer as return type!

Caused by: java.lang.IllegalArgumentException: Modifying queries can only use void or int/Integer as return type!…

Return type declarations返回类型声明

PHP 7.新增了返回类型声明 http://php.net/manual/en/functions.returning-values.php 在PHP 7.1中新增了返回类型声明为void,以及类型前面增加问号表示可以返回null,例如?init,不过和某些语言中的细节略有不同,没什么技术含量,就是语言的定义,直接上代码吧. php -r "function a() : int {return 1;} var_dump(a());" int(1) php -r "funct…

error C2556: 'const char &MyString::operator [](int)' : overloaded function differs only by return type from 'char &MyString::operator [](int)'

char & operator[](int i);const char & operator[](int i);/*const char & operator(int i);*/编译出错:error C2556: 'const char &MyString::operator [](int)' : overloaded function differs only by return type from 'char &MyString::operator [](int…

PHP empty()函数：Can't use method return value in write context

<?php if (!empty (get_gpc('userId'))) { $userId = get_gpc('userId'); } else { $error = "ID doesn't exist"; } 报错: Fatal error: Can't use method return value in write context in (line number) 为什么? empty()函数是检查一个变量是否为空,但是 get_gpc() 是个函数,所以得改下,参考…

new types may not be defined in a return type(c++语言编译错误，处理)

在写程序的时候,定义类时要在大括号后面加上: class Point{ public: Point(int a,int b); Point(const Point &p); int getx(Point p); int gety(Point p); private: int x,y; } 最后大括号一定要加上分号,上面是错误实例,编译出错 ew types may not be defined in a return type 所以一定别忘了结尾的分号: class Point{ public:…