maven搭建ssm框架问题总结

1. 

Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.6.0:compile (default-compile) on project jcseg-core: Compilation failure
[ No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK?

解决：把 JRE 路径从 JRE 改成 JDK： 

Window → Preferences → 对话框中的左侧选择Java → Installed JREs → 对话框右侧点击 Add 按钮 → Standard VM → next → JRE home 选择 JDK 的安装路径 → Finish → 选中 jdk 的复选框 → 点击 OK 按钮
按照《Maven实战》的内容，建议你不要使用 eclipse 内嵌的 Maven。而是给 eclipse 配置电脑上安装的 Maven。这样保证版本一致，可以避免一些问题。

2.

Caused by: java.net.BindException: Address already in use: JVM_Bind <null>:8080

解决：端口被占用，可能运行两次tomcat

3.

严重: Compilation error org.eclipse.jdt.internal.compiler.classfmt.ClassFormatException：
严重: Servlet.service() for servlet jsp threw exception
org.apache.jasper.JasperException: Unable to compile class for JSP:

An error occurred at line: 1 in the generated java file
The type java.io.ObjectInputStream cannot be resolved. It is indirectly referenced from required .class files

解决：项目正常启动,但是无法在浏览器中打开，报的错是 org.eclipse.jdt.internal.compiler.classfmt.ClassFormatException，是tomcat:run的问题

在web项目的pom文件中增加tomcat7配置

<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<version>2.2</version>
<configuration>
<port>9999</port> 
<uriEncoding>UTF-8</uriEncoding>
</configuration>
</plugin>

启动tomcat插件,不过这次的命令不是tomcat:run 而是tomcat7:run 因为前者不会调用tomcat7；

4.ssm整合时出现

java.sql.SQLException: The server time zone value '�й���׼ʱ��' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.
Caused by: com.mysql.cj.core.exceptions.InvalidConnectionAttributeException: The server time zone value '�й���׼ʱ��' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.

解决：配置pom.xml时使用的是MySQL最新jar包，原来新版的驱动配置有些变化：

5. url连接必须设置时区
### MySQL Connector/J 5.x (旧版连接)
#jdbc.url=jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf8

### MySQL Connector/J 6.x (新版连接)
jdbc.url=jdbc:mysql:///test?serverTimezone=UTC&characterEncoding=utf8&useUnicode=true&useSSL=false

说明： 新版驱动url默认地址为127.0.0.1:3306，所以访问本机mysql数据库地址可以用 /// 表示。

6. 新的驱动类位置有了变化（不影响使用，但会报警告）

### MySQL Connector/J 5.x (旧版驱动)
#jdbc.driver_class=com.mysql.jdbc.Driver

### MySQL Connector/J 6.x (新版驱动)
jdbc.driver_class=com.mysql.cj.jdbc.Driver

7.

org.apache.ibatis.reflection.ReflectionException: There is no getter for property named 'did' in 'class com.ssm.entity.User'

解决：是因为在user实体类中封装dept属性时，在mapper.xml中的增加insert数据库sql中写的是did，应该写成dept.did

8.

Caused by: org.springframework.beans.factory.BeanCreationException: 
Could not autowire field: private com.taobao.mapper.ProductMapper com.taobao.service.ProductServiceImpl.productMapper; 
nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.taobao.mapper.ProductMapper] found for dependency: 
expected at least 1 bean which qualifies as autowire candidate for this dependency. 
Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

解决：applicationContex.xml中没有正确配置MapperScannerConfigurer

9.

[ERROR] Failed to execute goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.2:generate (default-cli) on project mmall_learning: Execution default-cli of goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.2:generate failed: Cannot resolve classpath entry: /Users/yujie/Workspaces/IdeaProjects/mmall_learing/lib/mysql-connector-java-5.1.6-bin.jar -> [Help 1]

解决：原因是datasource.properties中的db.driverLocation=/Users/Administrator/workspace/yhMall/tools/mysql-connector-java-5.1.6-bin.jar

路径错误，找不到mysqljar包，更改路径即可

10错误：Caused by: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: java.lang.IllegalArgumentException: Result Maps collection already contains value for com.mmall.dao.OrderMapper.BaseResultMap

Caused by: java.lang.IllegalArgumentException: Result Maps collection already contains value for com.mmall.dao.OrderMapper.BaseResultMap

解决：原因是我在使用mybatis逆向工程时，重复使用了两次，结果在对应的映射文件中重复生成了两份内容，所有 Result Maps collection already contains value错误

11.问题：Caused by: java.lang.ClassCastException: org.springframework.web.SpringServletContainerInitializer cannot be cast to javax.servlet.ServletContainerInitializer

解决：原因：在我的pom.xml文件中javax.servlet-api.jar包发生冲突。当程序运行时与tomcat中的jar包冲突了，只需要它在测试、编译阶段有用
可以限制作用范围

12.问题：Caused by: org.apache.catalina.LifecycleException: A child container failed during start

在pom.xml引入的servlet-api依赖时，需要加入<scope>provided</scope>这个配置，意思是这个servlet-api的依赖包只在编译和测试时使用而不在运行时使用

13.Caused by: java.lang.UnsupportedOperationException
解决：原因是我的namespace中的select返回类型 resultType是List,应该是resultType返回的是集合中的元素类型，而不是集合本身

14.插入的时候，userMapper.xml如果使用的是values(#{id},#{name},#{age},#{sex}),不能加双引号。
如果使用的是values(${id},"${name}","${age}","${sex}"），需要加双引号

15.错误：Caused by: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: java.lang.IllegalArgumentException: Result Maps collection already contains value for com.mmall.dao.OrderMapper.BaseResultMap

Caused by: java.lang.IllegalArgumentException: Result Maps collection already contains value for com.mmall.dao.OrderMapper.BaseResultMap

解决：原因是我在使用mybatis逆向工程时，重复使用了两次，结果在对应的映射文件中重复生成了两份内容，所有 Result Maps collection already contains value错误


16.问题：Caused by: java.lang.ClassCastException: org.springframework.web.SpringServletContainerInitializer cannot be cast to javax.servlet.ServletContainerInitializer

解决：原因：在我的pom.xml文件中javax.servlet-api.jar包发生冲突。当程序运行时与tomcat中的jar包冲突了，只需要它在测试、编译阶段有用
可以限制作用范围


17.问题：java.lang.NoClassDefFoundError: ch/qos/logback/core/joran/spi/JoranException
解决：必须引入logback-classic-0.9.24.jar/logback-core-0.9.24.jar这两个jar包，切版本要一致

18.org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.mybatis.spring.mapper.MapperScannerConfigurer#0' defined in class path resource [applicationContext.xml]: Initialization of bean failed; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type [java.lang.String] to required type [org.apache.ibatis.session.SqlSessionFactory] for property 'sqlSessionFactory'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.apache.ibatis.session.SqlSessionFactory] for property 'sqlSessionFactory': no matching editors or conversion strategy found
Caused by: org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type [java.lang.String] to required type [org.apache.ibatis.session.SqlSessionFactory] for property 'sqlSessionFactory'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.apache.ibatis.session.SqlSessionFactory] for property 'sqlSessionFactory': no matching editors or conversion strategy found
Caused by: java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.apache.ibatis.session.SqlSessionFactory] for property 'sqlSessionFactory': no matching editors or conversion strategy found
原因可能如下：1）@RequestMapping(value="/userlogin",method=RequestMethod.POST)
2）<!-- 配置映射接口 -->中property name="sqlSessionFactoryBeanName"

19..org.apache.ibatis.executor.ExecutorException:A query was run and no Result Maps were found for the Mapped Statement 'com.blog.mapper.BlogMapper.findAllBlog'. It's likely that neither a Result Type nor a Result Map was specified.
解决：仔细查看mybatis的配置文件，发现遗漏一个属性：resultType
报错的配置是：<select id="ID" parameterType="java.util.Map">
正确的配置应该是<select id="ID" parameterType="java.util.Map" resultType="java.util.Map">

最后总结下，就是mybatis中的所有查询，都必须返回resultType或者resultMap的值，否则就会报如上错误的。

20.java.lang.NullPointerException
at com.blog.service.impl.BlogServiceImpl.findAllBlog(BlogServiceImpl.java:31)
at com.blog.controller.BlogController.findAllBlog(BlogController.java:27)
解决：空指针异常，可能是依赖关系没有确定，看看属性上是否添加@Autowired

21.java.lang.IllegalArgumentException: Invalid character found in method name. HTTP method names must be tokens
严重: Servlet.service() for servlet [springmvc] in context with path [/blog] threw exception [Request processing failed; nested exception is org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.binding.BindingException: Parameter 'username' not found. Available parameters are [arg1, arg0, param1, param2]] with root cause
org.apache.ibatis.binding.BindingException: Parameter 'username' not found. Available parameters are [arg1, arg0, param1, param2]
解决： 查询中参数没有指定，比如：//根据用户名和密码查询 User find(String username,String password)应写成//根据用户名和密码查询
User find(@Param("username")String username,@Param("password")String password);

22.java.lang.NoSuchMethodException: com.opensymphony.xwork2.ActionSupport.login()

解决：applicationContext.xml中的依赖关系没有注入

23.Caused by: java.lang.IllegalArgumentException: 'sessionFactory' or 'hibernateTemplate' is required
解决：applicationContext.xml中的依赖关系dao中没有主人sessionFactory

24.Caused by: Action class [userAction] not found - action
解决：其实是缺少包struts2-sping-plugin 2.0.1.jar

25.使用c3p0数据源时，下边的数据库属性分别是：driverClass，jdbcUrl，user，password
使用springjdbc数据源时，下边的数据库属性分别是：driverClassName，url，username，password

26.Caused by: org.springframework.beans.NotWritablePropertyException: Invalid property 'dataSource' of bean class [org.mybatis.spring.transaction.SpringManagedTransactionFactory]: Bean property 'dataSource' is not writable or has an invalid setter method. Do

原因：＜property name="dataSource"＞应该驼峰命名，结果直接复制粘贴成小写了

27.问题：java.lang.IllegalArgumentException: No converter found for return value of type: class java.util.ArrayList
解决：忘记加入json相关jar包

28.Caused by: java.lang.NumberFormatException: For input string: "${spring.datasource.initialSize}"
解决：application.preperties中属性名和上面的不一致

29.java.lang.NumberFormatException: For input string: "userName"
解决：因为返回的item是一个object的数组，$(item.userName)这种访问方式是不能用来访问数组的

30.java.lang.IllegalArgumentException: No converter found for return value of type: class com.ssm.entity.ResponseObj
解决：这是因为springmvc默认是没有对象转换成json的转换器的，需要手动添加jackson依赖。

31.错误：Caused by: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. Cause: java.lang.IllegalArgumentException: Result Maps collection already contains value for com.mmall.dao.OrderMapper.BaseResultMap

Caused by: java.lang.IllegalArgumentException: Result Maps collection already contains value for com.mmall.dao.OrderMapper.BaseResultMap

解决：原因是我在使用mybatis逆向工程时，重复使用了两次，结果在对应的映射文件中重复生成了两份内容，所有 Result Maps collection already contains value错误

32.问题：Caused by: java.lang.ClassCastException: org.springframework.web.SpringServletContainerInitializer cannot be cast to javax.servlet.ServletContainerInitializer

解决：原因：在我的pom.xml文件中javax.servlet-api.jar包发生冲突。当程序运行时与tomcat中的jar包冲突了，只需要它在测试、编译阶段有用
可以限制作用范围

33.问题：java.lang.NoClassDefFoundError: ch/qos/logback/core/joran/spi/JoranException
解决：必须引入logback-classic-0.9.24.jar/logback-core-0.9.24.jar这两个jar包，切版本要一致