系统变量配置
linux 下：（profile文件增加）
1、----该配置jvm不生效
#无用户名密码
export http_proxy=http://proxy_ip:prot
export https_proxy=https://proxy_ip:prot
#有用户名密码
export http_proxy=http://username:password@proxy_ip:prot
export https_proxy=https://username:password@proxy_ip:port
2、export _JAVA_OPTIONS="-Dhttp.proxyHost=172.17.17.155 -Dhttp.proxyPort=8180 -Dhttp.nonProxyHosts=\"localhost|127.0.0.1|172.20.190.*\""（\转义符）
jvm配置(几种配置)：
1、 java -Dhttp.proxyHost=172.17.17.155 -Dhttp.proxyPort=8180 Do..
2、catalina.sh 增加如下：JAVA_OPTS="-Dhttp.proxyHost=172.17.17.155 -Dhttp.proxyPort=8180 -Dhttp.nonProxyHosts=\"localhost|127.0.0.1|172.20.190.*\""
java coding
System.setProperty("http.proxyHost","172.17.17.155");
System.setProperty("http.proxyPort","8180");
URLConnection
InetSocketAddress addr = new InetSocketAddress("172.17.17.155",8180);
Proxy proxy = new Proxy(Proxy.Type.HTTP, addr); // http 代理
HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();