maven：如何查找jar包的dependency
在项目中需要使用到某个jar包时，我们一般会用maven导入该jar，但是该jar需要依赖一些别的jar包，这时你想找出这个jar包到底依赖了哪些包，或者这么说，你有一个需求：把pom.xml中所有的dependency的依赖树状图勾画出来。
具体的做法：在命令行模式下，进入pom.xml所在目录，然后输入命令：
mvn dependency:tree
则会有类似以下格式的输出：
[INFO] [dependency:tree {execution: default-cli}]
[INFO] org.springframework.samples:mvc-ajax:war:1.0.0-SNAPSHOT
[INFO] +- org.springframework:spring-context:jar:3.0.5.RELEASE:compile
[INFO] | +- org.springframework:spring-aop:jar:3.0.5.RELEASE:compile
[INFO] | | \- aopalliance:aopalliance:jar:1.0:compile
[INFO] | +- org.springframework:spring-beans:jar:3.0.5.RELEASE:compile
[INFO] | +- org.springframework:spring-core:jar:3.0.5.RELEASE:compile
[INFO] | +- org.springframework:spring-expression:jar:3.0.5.RELEASE:compile
[INFO] | \- org.springframework:spring-asm:jar:3.0.5.RELEASE:compile
[INFO] +- org.springframework:spring-webmvc:jar:3.0.5.RELEASE:compile
[INFO] | +- org.springframework:spring-context-support:jar:3.0.5.RELEASE:
compile
[INFO] | \- org.springframework:spring-web:jar:3.0.5.RELEASE:compile
[INFO] +- org.slf4j:slf4j-api:jar:1.6.1:compile
[INFO] +- org.slf4j:jcl-over-slf4j:jar:1.6.1:runtime
[INFO] +- org.slf4j:slf4j-log4j12:jar:1.6.1:runtime
[INFO] +- log4j:log4j:jar:1.2.16:runtime
[INFO] +- javax.validation:validation-api:jar:1.0.0.GA:compile
[INFO] +- org.hibernate:hibernate-validator:jar:4.1.0.Final:compile
[INFO] +- joda-time:joda-time:jar:1.6.2:runtime
[INFO] +- org.codehaus.jackson:jackson-mapper-asl:jar:1.6.4:compile
[INFO] | \- org.codehaus.jackson:jackson-core-asl:jar:1.6.4:compile
[INFO] +- javax.servlet:servlet-api:jar:2.5:provided
[INFO] +- javax.servlet.jsp:jsp-api:jar:2.1:provided
[INFO] +- javax.servlet:jstl:jar:1.2:compile
[INFO] +- junit:junit:jar:4.7:test
[INFO] \- org.springframework:spring-test:jar:3.0.5.RELEASE:test
[INFO] ---------------------------------------------------------------
[INFO] BUILD SUCCESSFUL
[INFO] ---------------------------------------------------------------
[INFO] Total time: 1 minute 8 seconds
[INFO] Finished at: Tue Jan 04 16:53:45 CET 2011
[INFO] Final Memory: 12M/25M
[INFO] ---------------------------------------------------------------[img][/img]
整个pom.xml的依赖树状图一目了然。
外国的一位仁兄也遇到了类似的问题：
http://stackoverflow.com/questions/4594475/how-to-figure-out-the-jars-that-the-dependencies-in-the-mavens-pom-xml-depend-o
