修改eclipse中maven工程中默認javaSE1.5版本 以及project facet中java版本

1.修改maven默認javase版本號

修改Maven中conf目錄裏的setting.xml文件內容，加上如下內容：

<profiles>
		<!-- profile | Specifies a set of introductions to the build process, to 
			be activated using one or more of the | mechanisms described above. For inheritance 
			purposes, and to activate profiles via <activatedProfiles/> | or the command 
			line, profiles have to have an ID that is unique. | | An encouraged best 
			practice for profile identification is to use a consistent naming convention 
			| for profiles, such as 'env-dev', 'env-test', 'env-production', 'user-jdcasey', 
			'user-brett', etc. | This will make it more intuitive to understand what 
			the set of introduced profiles is attempting | to accomplish, particularly 
			when you only have a list of profile id's for debug. | | This profile example 
			uses the JDK version to trigger activation, and provides a JDK-specific repo. -->
		<profile>
			<id>jdk-1.8</id>
			<activation>
				<activeByDefault>true</activeByDefault>
				<jdk>1.8</jdk>
			</activation>
			<properties>  
				<maven.compiler.source>1.8</maven.compiler.source>  
				<maven.compiler.target>1.8</maven.compiler.target>  
				<maven.compiler.compilerVersion>1.8</maven.compiler.compilerVersion>  
			</properties>
			<repositories>
				<repository>
					<id>nexus</id>
					<name>local private nexus</name>
					<url>http://maven.oschina.net/content/groups/public/</url>
					<releases>
						<enabled>true</enabled>
					</releases>
					<snapshots>
						<enabled>false</enabled>
					</snapshots>
				</repository>
			</repositories>
			<pluginRepositories>
				<pluginRepository>
					<id>nexus</id>
					<name>local private nexus</name>
					<url>http://maven.oschina.net/content/groups/public/</url>
					<releases>
						<enabled>true</enabled>
					</releases>
					<snapshots>
						<enabled>false</enabled>
					</snapshots>
				</pluginRepository>
			</pluginRepositories>
		</profile>


		<!-- | Here is another profile, activated by the system property 'target-env' 
			with a value of 'dev', | which provides a specific path to the Tomcat instance. 
			To use this, your plugin configuration | might hypothetically look like: 
			| | ... | <plugin> | <groupId>org.myco.myplugins</groupId> | <artifactId>myplugin</artifactId> 
			| | <configuration> | <tomcatLocation>${tomcatPath}</tomcatLocation> | </configuration> 
			| </plugin> | ... | | NOTE: If you just wanted to inject this configuration 
			whenever someone set 'target-env' to | anything, you could just leave off 
			the <value/> inside the activation-property. | <profile> <id>env-dev</id> 
			<activation> <property> <name>target-env</name> <value>dev</value> </property> 
			</activation> <properties> <tomcatPath>/path/to/tomcat/instance</tomcatPath> 
			</properties> </profile> -->
	</profiles>

其中的1.8修改爲你需要的jdk版本號，然後在eclipse裏的項目右擊鼠標-Maven-select Maven profiles，選擇對應的jdk參數，然後更新項目就可以了

2.修改project

右擊項目，點擊Properties->Project Facets

 

如上圖可以看到項目爲web2.3 java1.5 當然我們也可以改成我們所需要的版本，打開xml文件my-app-web/.settings/org.eclipse.wst.common.project.facet.core.xml，進行修改即可：

Xml代碼  

1. <?xml version="1.0" encoding="UTF-8"?>  

2. <faceted-project>  

3.   <fixed facet="wst.jsdt.web"/>  

4.   <installed facet="java" version="1.8"/>  

5.   <installed facet="jst.web" version="3.0"/>  

6.   <installed facet="wst.jsdt.web" version="1.0"/>  

7. </faceted-project>  

修改後保存，在eclipse中刷新項目，然後右擊項目，點擊Properties->Project Facets查看：

轉自  https://my.oschina.net/JustLoveIT/blog/412799

         https://www.oschina.net/question/96320_62556