What is the role of the. classpath and. project files in the MyEclipse project?

. Project is a project file, where the structure of the project is defined, such as the location of the Lib, the location of the SRC, the location of the classes
The location of the. CLASSPATH defines the $classpath you use for this project at compile time

. classpath file
From the data we can easily see that the above describes the project's dependent files:
The exact location of the source file (kind= "src")
Operating system environment (kind= "con")
Specific location information for the project's library (kind= "Lib")
In each LIB's XML child node, there is additional configuration information about it (for example, configuring "Javadoc_location" "Path" "Sourcespath")
Output Directory of the project (kind= "Output")
In general, this document is the configuration of the entire project operating environment.

. project file
From the data, we can see that these configurations are primarily about describing the basic engineering information:
Project Name <name></name>
Project Comment Description <comment></comment>
Additional Eclipse plugins required for runtime <natures></natures>
and its specific loading mode information <buildSpec></buildSpec>

If you add a lot of additional plugins to your project during the development process, it will inevitably cause your eclipse to start slowly. In this case, you can remove some plugins from this file, but you will be loading those plugins when you open those associated files.

You can see a. classpath file for Demo

<?xml version= "1.0" encoding= "UTF-8"? ><classpath><classpathentry kind= "src" path= "src"/>< Classpathentry kind= "Con" path= "org.eclipse.jdt.launching.jre_container/ Org.eclipse.jdt.internal.debug.ui.launcher.standardvmtype/jre7 "><attributes><attribute name=" Owner.project.facets "value=" java "/></attributes></classpathentry><classpathentry kind=" Con " Path= "Org.eclipse.jst.server.core.container/org.eclipse.jst.server.tomcat.runtimetarget/apache Tomcat v7.0" > <attributes><attribute name= "Owner.project.facets" value= "Jst.web"/></attributes></ Classpathentry><classpathentry kind= "Con" path= "Org.eclipse.jst.j2ee.internal.web.container"/>< Classpathentry kind= "Con" path= "Org.eclipse.jst.j2ee.internal.module.container"/><classpathentry kind= "Lib" Path= "E:/bishe/apache-tomcat-7.0.34/lib/servlet-api.jar" sourcepath= "f:/360 speed Browser Download/ Javax.servlet-3.0-sources.jar "/><classpathentry kind=" Output "path=" Build/claSSEs "/></classpath> 

<?xml version= "1.0" encoding= "UTF-8"? ><projectdescription><name>xxxx</name><comment ></comment><projects></projects><buildSpec><buildCommand><name> Org.eclipse.wst.jsdt.core.javascriptvalidator</name><arguments></arguments></buildcommand ><buildcommand><name>org.eclipse.jdt.core.javabuilder</name><arguments></ Arguments></buildcommand><buildcommand><name> org.eclipse.wst.common.project.facet.core.builder</name><arguments></arguments></ buildcommand><buildcommand><name>org.eclipse.wst.validation.validationbuilder</name>< Arguments></arguments></buildcommand></buildspec><natures><nature> Org.eclipse.jem.workbench.javaemfnature</nature><nature> Org.eclipse.wst.common.modulecore.modulecorenature</nature><nature> org.eclipse.wst.common.project.facet.core.nature</nature><nature>org.eclipse.jdt.core.javanature</nature><nature> Org.eclipse.wst.jsdt.core.jsnature</nature></natures></projectdescription>

Is it necessary for any Java project?
The feeling should not be, these commands can also be set through the command line, just some of the eclipse construction standards

What is the role of the. classpath and. project files in the MyEclipse project?