maven

 CoreException: Could not calculate build plan: Plugin org.apache.maven.plugins:maven-compiler-plugin:2.3.2 or one of its dependencies could not be resolved: Failed to read artifact descriptor for
 org.apache.maven.plugins:maven-compiler-plugin:jar:2.3.2: ArtifactResolutionException: Failure to transfer org.apache.maven.plugins:maven-compiler-plugin:pom:2.3.2 from http://repo1.maven.org/
 maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced. Original error: Could not transfer artifact
 org.apache.maven.plugins:maven-compiler-plugin:pom:2.3.2 from/to central (http://repo1.maven.org/maven2): Connect times out

解決方式：
1.找到maven庫目錄，進入：~\.m2\repository\org\apache\maven\plugins\maven-surefire-plugin\2.7.1

2.若2.7.1目錄下只有，"maven-surefire-plugin-2.7.1.pom.lastUpdated" 則須要到http://repo1.maven.org/maven2/org/apache/maven/plugins/maven-surefire-plugin/2.7.1/，把裏面的文件下載下來放到2.7.1

3.刪除2.7.1下的maven-surefire-plugin-2.7.1.pom.lastUpdated文件。

4.項目右鍵-->maven-->Update Dependencies