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如何用 JPA 实现多对多查询

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1

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class="cursor-pointer"> 错误截图

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spring用@Autowired自动注入时idea老是报错？

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class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

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命名为applicationContext.xml，后缀不管用

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1

SSM

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.0.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">

<context:annotation-config/>
    <context:component-scan base-package="com"/>

<aop:aspectj-autoproxy proxy-target-class="true"/>

<mvc:annotation-driven/>

<mvc:default-servlet-handler/>

</beans>

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使用阿里云的OSS，启动时找不到jar里的类

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class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

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第一次使用IDEA时找不到.properties,Mapper.xml文件

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spring mybatis

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class="cursor-pointer"> 错误截图

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为什么添加或者修改页面，jsp页面没有跳转？

1

SSM

class="cursor-pointer"> 详细描述

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class="cursor-pointer"> 源码

list.jsp里面的代码是：
<form action="${pageContext.request.contextPath}/student/add" method="get">
			</s:forEach>
			<input type="submit" value="增加">
		</form>

Controller里面的类
//添加学员跳转页
    @RequestMapping(value = "/student/add", method = RequestMethod.GET)
    public String toAddStudent() {
        return "add";
    }

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log4j写入文件的时候打印信息是红字

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class="cursor-pointer"> 详细描述

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在客户端连接远程的服务端时连接被拒绝

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分布式

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

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redisTemplate存入byte[]类型失败

1

redis

class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图

class="cursor-pointer"> 源码

public class Sigupserviceimpl implements Signupservice{

    @Autowired(required = false)
    private  SignupDao signupDao;

    @Autowired
    private RedisTemplate redisTemplate;

    public List<Signup> getSignupByPage(int start,int limit) {
        ArrayList IdList = new ArrayList();
        List<Signup> List2 = new ArrayList<Signup>();
        if (redisTemplate.opsForValue().get(String.valueOf(start)+"page")!=null){
            IdList = (ArrayList) redisTemplate.opsForValue().get(String.valueOf(start)+"page");
            for (int i = 0; i <IdList.size() ; i++) {
                List2.add((Signup) redisTemplate.opsForValue().get(String.valueOf(IdList.get(i))));
            }
            System.out.println("缓存存在");
        }else {
            List2 = signupDao.selectSignup(start,limit);
            for (Signup s:List2){
                IdList.add(s.getId());
                redisTemplate.opsForValue().set(String.valueOf(s.getId()),s,500, TimeUnit.SECONDS);
            }
            redisTemplate.opsForValue().set(String.valueOf(start)+"page",IdList,500,TimeUnit.SECONDS);
            System.out.println("缓存不存在");
        }
        return List2;
    }
    //  单个查询
    public Signup GetSignupById(long id){
        String ids = String.valueOf(id);
        Signup signup = (Signup) redisTemplate.opsForValue().get(ids);
        if (signup!=null){
            System.out.println("有缓存");
            return signup;
        }else {
            signup=signupDao.GetSignupById(id);
            if (signup!=null){
                redisTemplate.opsForValue().set(ids,signup,60*50,TimeUnit.SECONDS);
            }else {
//                memcachedClient.set(ids,60*5,null);
                redisTemplate.opsForValue().set(ids,null,60*5,TimeUnit.SECONDS);
            }
        }

        return signupDao.GetSignupById(id);
    }
    //更新
    public int updateByPrimaryKey(Signup signup) {
        int result = signupDao.updateByPrimaryKey(signup);
//        memcachedClient.set(String.valueOf(signup.getId()),60*12,signup);
        redisTemplate.opsForValue().set(String.valueOf(signup.getId()),signup,60*12,TimeUnit.SECONDS);
        return result;
    }

    public int InsertSign(Signup signup)  {
//        memcachedClient.flushAll();
        return signupDao.insertSignup(signup);
    }

    public List<Signup> getSignAll(){
        return signupDao.GetSignAll();
    }

    public int DeleteById(long id) {
        redisTemplate.delete(String.valueOf(id));
        int result = signupDao.deleteSignupById(id);
        redisTemplate.delete("0page");
        return result;
    }

}

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执行数据库更新语句时报错

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class="cursor-pointer"> 详细描述

class="cursor-pointer"> 错误截图