Eclipse需要安裝一個Jcoco的插件，但是連接Eclipse Market的時候，總是出現如下的報錯：
Cannot open Eclipse Marketplace
Cannot install remote marketplace locations: Connection failed
This is most often caused by a problem with your internet connection. Please check your internet connection and retry.
Cannot complete request to http://marketplace.eclipse.org/catalogs/api/p: Unable to connect to repository http://marketplace.eclipse.org/catalogs/api/p
Unable to connect to repository http://marketplace.eclipse.org/catalogs/api/p
Connection to http://marketplace.eclipse.org refused
Connection failed
This is most often caused by a problem with your internet connection. Please check your internet connection and retry.
Connection to http://marketplace.eclipse.org refused
解決方案：
1、修改eclipse.ini文件，在文件末尾添加如下內容：
-Djava.net.preferIPv4Stack=true
2、通過安裝插件的方式，手動添加Eclipse Market
點擊 help->Install new SoftWare->add
輸入插件名：Market Client
輸入路徑：http://download.eclipse.org/mpc/indigo/
添加完成后，選擇Eclipse Marketplace Client,下載安裝即可。