Maven插件wro4j-maven-plugin压缩、合并js、css详解

1.    在pom.xml文件中，引入wro4j-maven-plugin插件

1. <plugin>
2.     <groupId>ro.isdc.wro4j</groupId>
3.     <artifactId>wro4j-maven-plugin</artifactId>
4.     <version>${wro4j.version}</version>
5.  
6.     <executions>
7.         <execution>
8.             <id>optimize-web-resources</id>
9.             <phase>compile</phase>
10.             <goals>
11.                 <goal>run</goal>
12.             </goals>
13.         </execution>
14.     </executions>
15.  
16.     <configuration>
17.         <ignoreMissingResources>false</ignoreMissingResources>
18.         <jsDestinationFolder>
19.             ${project.build.directory}/${project.build.finalName}/static/js
20.         </jsDestinationFolder>
21.         <cssDestinationFolder>
22.             ${project.build.directory}/${project.build.finalName}/static/css
23.         </cssDestinationFolder>
24.         <wroManagerFactory>
25.             ro.isdc.wro.maven.plugin.manager.factory.ConfigurableWroManagerFactory
26.         </wroManagerFactory>
27.     </configuration>
28. </plugin>

2.    配置合并、压缩策略，新建文件/WEB-INF/wro.xml，例如配置内容为：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <groups xmlns="http://www.isdc.ro/wro" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
3.     xsi:schemaLocation="http://www.isdc.ro/wro wro.xsd">
4.     <group name="basic">
5.         <css>/static/css/front.css</css>
6.         <js>/static/js/jquery.js</js>
7.         <js>/static/js/jquery.paging.min.js</js>
8.         <js>/static/js/front/global.js</js>
9.         <js>/static/js/front/search.js</js>
10.     </group>
11.  
12.     <group name="custom">
13.         <css>/static/css/front.css</css>
14.         <css>/static/css/comment/comment.css</css>
15.         <css>/static/plugins/syntaxhighlighter/shCore.css</css>
16.         <js>/static/js/front/coding.js</js>
17.     </group>
18.  
19. </groups>

3.    配置wro4j相关属性，新建WEB-INF/wro.properties，例如配置内容为：
配置属性含义参见：http://everycoding.com/coding/68.html

1. cacheUpdatePeriod=0
2. modelUpdatePeriod=0
3. debug=true
4. disableCache=false
5. gzipResources=true
6. ignoreMissingResources=false

此插件必须配置wro.properties。否则在执行打包命令:clean package时否则会报如下异常：
srcmainwebappWEB-INFwro.properties (系统找不到指定的文件。) -> [Help 1]

4.    执行maven命令：clean package 打包
我们会发现根据wro.xml配置的策略在
${project.build.directory}/${project.build.finalName}/static/js
${project.build.directory}/${project.build.finalName}/static/css的目录下生成了
basic.css、basic.js、custom.css、custom.js等合并压缩后的文件。