解决Cannot change version of project facet Dynamic web module to 2.5

我们用Eclipse创建Maven结构的web项目的时候选择了Artifact Id为maven-artchetype-webapp，由于这个catalog比较老，用的servlet还是2.3的，而一般现在至少都是2.5，在Project Facets里面修改Dynamic web module为2.5的时候就会出现Cannot change version of project facet Dynamic web module to 2.5，如图：

其实在右边可以看到改到2.5需要的条件以及有冲突的facets，解决这个问题的步骤如下：

1.把Servlet改成2.5，打开项目的web.xml，改之前：

[html] view plain copy print?

    <!DOCTYPE web-app PUBLIC        "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"        "http://java.sun.com/dtd/web-app_2_3.dtd" >       <web-app>         <display-name>Archetype Created Web Application</display-name>       </web-app>  

改后：

[html] view plain copy print?

    <?xml version="1.0" encoding="UTF-8"?>       <web-app version="2.5"           xmlns="http://java.sun.com/xml/ns/javaee"           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"           xsi:schemaLocation="http://java.sun.com/xml/ns/javaee           http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">         <display-name>Archetype Created Web Application</display-name>       </web-app>  

2.修改项目的设置，在Navigator下打开项目.settings目录下的org.eclipse.jdt.core.prefs

[html] view plain copy print?

    eclipse.preferences.version=1       org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled       org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.5       org.eclipse.jdt.core.compiler.compliance=1.5       org.eclipse.jdt.core.compiler.problem.assertIdentifier=error       org.eclipse.jdt.core.compiler.problem.enumIdentifier=error       org.eclipse.jdt.core.compiler.problem.forbiddenReference=warning       org.eclipse.jdt.core.compiler.source=1.5  

把1.5改成1.6

[html] view plain copy print?

    eclipse.preferences.version=1       org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled       org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.6       org.eclipse.jdt.core.compiler.compliance=1.6       org.eclipse.jdt.core.compiler.problem.assertIdentifier=error       org.eclipse.jdt.core.compiler.problem.enumIdentifier=error       org.eclipse.jdt.core.compiler.problem.forbiddenReference=warning       org.eclipse.jdt.core.compiler.source=1.6  

打开org.eclipse.wst.common.component

[html] view plain copy print?

    <?xml version="1.0" encoding="UTF-8"?>       <project-modules id="moduleCoreId" project-version="1.5.0">           <wb-module deploy-name="test">               <wb-resource deploy-path="/" source-path="/target/m2e-wtp/web-resources"/>               <wb-resource deploy-path="/" source-path="/src/main/webapp" tag="defaultRootSource"/>               <wb-resource deploy-path="/WEB-INF/classes" source-path="/src/main/java"/>               <wb-resource deploy-path="/WEB-INF/classes" source-path="/src/main/resources"/>               <property name="context-root" value="test"/>               <property name="java-output-path" value="/test/target/classes"/>           </wb-module>       </project-modules>  

把project-version="1.5.0"改成project-version="1.6.0"

[html] view plain copy print?

    <?xml version="1.0" encoding="UTF-8"?>       <project-modules id="moduleCoreId" project-version="1.6.0">           <wb-module deploy-name="test">               <wb-resource deploy-path="/" source-path="/target/m2e-wtp/web-resources"/>               <wb-resource deploy-path="/" source-path="/src/main/webapp" tag="defaultRootSource"/>               <wb-resource deploy-path="/WEB-INF/classes" source-path="/src/main/java"/>               <wb-resource deploy-path="/WEB-INF/classes" source-path="/src/main/resources"/>               <property name="context-root" value="test"/>               <property name="java-output-path" value="/test/target/classes"/>           </wb-module>       </project-modules>  

打开org.eclipse.wst.common.project.facet.core.xml

[html] view plain copy print?

    <?xml version="1.0" encoding="UTF-8"?>       <faceted-project>         <fixed facet="wst.jsdt.web"/>         <installed facet="java" version="1.5"/>         <installed facet="jst.web" version="2.3"/>         <installed facet="wst.jsdt.web" version="1.0"/>       </faceted-project>  

把<installed facet="java" version="1.5"/>改成<installed facet="java" version="1.6"/>，把  <installed facet="jst.web" version="2.3"/>改成  <installed facet="jst.web" version="2.5"/>

[html] view plain copy print?

    <?xml version="1.0" encoding="UTF-8"?>       <faceted-project>         <fixed facet="wst.jsdt.web"/>         <installed facet="java" version="1.6"/>         <installed facet="jst.web" version="2.5"/>         <installed facet="wst.jsdt.web" version="1.0"/>       </faceted-project>  

都改好之后在打开看看，已经把Dynamic web module改成了2.5

http://blog.csdn.net/steveguoshao/article/details/38414145