ssm工程搭建常见问题

maven工程碰到如下问题；

报错：Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1

Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project TestProject: Compilation failure

pom文件中引入此即可

<plugin>
   <groupId>org.apache.maven.plugins</groupId>
   <artifactId>maven-compiler-plugin</artifactId>
   <version>3.6.1</version>
   <configuration>
      <source>1.8</source>
      <target>1.8</target>
   </configuration>
</plugin>

2.

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mappingJacksonHttpMessageConverter': Lookup method resolution failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter] from ClassLoader [WebappClassLoader

根本原因

java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/exc/InvalidDefinitionException

解决：jackson版本问题

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.8.9</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.9.5</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
    <version>2.9.5</version>

3.java.lang.ClassNotFoundException: org.apache.commons.fileupload.FileItemFactory

解决：增加依赖

<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.3</version>
</dependency>

applicationcontext.xml中引入bean

<bean id="multipartResolver"
      class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <property name="defaultEncoding" value="utf-8"/>
    <property name="maxUploadSize" value="10485760000"/>
    <property name="maxInMemorySize" value="2048"/>
</bean>

结果报新错如下：

org.springframework.beans.factory.BeanDefinitionStoreException: IOException parsing XML document from class path resource [applicationContext.xml]; nested exception is java.io.FileNotFoundException: class path resource [applicationContext.xml] cannot be opened because it does not exist

去掉该bean的定义后恢复正常，猜想是该依赖包与jdk的jar包有冲突？

报错：

 class path resource [applicationContext.xml] cannot be opened because it does not exist

4.

java.lang.ClassNotFoundException: org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter

解决：

5.

如何统一处理controller层的异常并返回

参考：https://www.pianshen.com/article/6779136224/