SSM 记录

Posted 2020-10-03 maoyan

前言：本过程从0开始，先是导入最核心的jar包，然后随着ssm中的功能实现，打包===>启动===>报错，一步步解决问题，增加额外的必须的jar包来熟悉ssm

1、导包(核心包)

mybatis:mybatis

msql:mysql-connector-java

spring:spring、spring-core、spring-web、spring-context、spring-beans

spring-mvc：spring-webmvc

mybatis-spring:mybatis-spring

2、配置文件

spring-mvc.xml

<?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" 
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd  
 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
 http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">
        <!-- 配置成拦截所有的请求，会有效@RequestMapper，如果是配置成*.do则无效 -->
        <mvc:annotation-driven />
        <!-- 扫描指定包下含有特定注解的类 -->
        <context:component-scan base-package="com.test.*"/>
        <!-- 静态资源请求，启动容器的默认的handler来处理 -->
        <mvc:default-servlet-handler/>
        <!-- 试图解析器 -->
        <bean  class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            <property name="prefix" value="/" />
            <property name="suffix" value=".jsp" />
        </bean>
</beans>

spring-mybatis.xml

<?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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    <!-- 数据库连接开始 -->
    <context:property-placeholder location="/WEB-INF/classes/datasource.properties"/>
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="${driver}"/>
        <property name="username" value="${jdbc_username}"/>
        <property name="url" value="${url}"/>
        <property name="password" value="${pwd}"/>
    </bean>
    <!-- 数据库连接结束 -->
</beans>

使用的context、mvc、tx、aop……标签时，需加上相应的协议

3、完善过程与问题记录

1)java.lang.NullPointerException

org.springframework.core.SerializableTypeWrapper$TypeProxyInvocationHandler.invoke(SerializableTypeWrapper.java:239)

问题：maven的传递依赖导致spring 4.2与spring 2.5包冲突，解决，在pom加入如下依赖，去掉spring依赖。

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>dubbo</artifactId>
    <version>2.5.3</version>
    <exclusions>
        <exclusion>
            <artifactId>spring</artifactId>
            <groupId>org.springframework</groupId>
        </exclusion>
    </exclusions>
</dependency>

2）增加mybatis数据库操作,在spring-mybatis.xml增加配置

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation" value="classpath:mapperAlias.xml" />
    </bean>
    
    <!-- DAO接口所在包名，Spring会自动查找其下的类 -->  
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">  
        <property name="basePackage" value="com.test.dao" />  
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>  
    </bean>

　　2.1）打包启动 错：java.lang.NoClassDefFoundError: org/springframework/dao/support/DaoSupport，增加spring-tx依赖

　　2.2）即上之后 打包启动 错误信息有java.lang.NoClassDefFoundError: org/springframework/jdbc/datasource/TransactionAwareDataSourceProxy 增加spring-jdbc的依赖

　　2.3）单元测试   nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.csdn.training.service.BeanB] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. 原因是缺少bean的依赖注入。

参考：http://blog.csdn.net/jiangchao858/article/details/51586515

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