java取得web容器位址的方法

複製代碼代碼如下:

public static Integer getTomcatPortFromConfigXml(File serverXml) {
Integer port;
try {
DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
domFactory.setNamespaceAware(true); // never forget this!
DocumentBuilder builder = domFactory.newDocumentBuilder();
Document doc = builder.parse(serverXml);
XPathFactory factory = XPathFactory.newInstance();
XPath xpath = factory.newXPath();
XPathExpression expr = xpath.compile
("/Server/Service[@name='Catalina']/Connector[count(@scheme)=0]/@port[1]");
String result = (String) expr.evaluate(doc, XPathConstants.STRING);
port = result != null && result.length() > 0 ? Integer.valueOf(result) : null;
} catch (Exception e) {
port = null;
}
return port;
}

複製代碼代碼如下:

另外：System.getProperty()中的字串參數如下：

System.getProperty()參數大全
# java.version Java Runtime Environment version
# java.vendor Java Runtime Environment vendor
# java.vendor.url Java vendor URL
# java.home Java installation directory
# java.vm.specification.version Java Virtual Machine specification version
# java.vm.specification.vendor Java Virtual Machine specification vendor
# java.vm.specification.name Java Virtual Machine specification name
# java.vm.version Java Virtual Machine implementation version
# java.vm.vendor Java Virtual Machine implementation vendor
# java.vm.name Java Virtual Machine implementation name
# java.specification.version Java Runtime Environment specification version
# java.specification.vendor Java Runtime Environment specification vendor
# java.specification.name Java Runtime Environment specification name
# java.class.version Java class format version number
# java.class.path Java class path
# java.library.path List of paths to search when loading libraries
# java.io.tmpdir Default temp file path
# java.compiler Name of JIT compiler to use
# java.ext.dirs Path of extension directory or directories
# os.name Operating system name
# os.arch Operating system architecture
# os.version Operating system version
# file.separator File separator ("/" on UNIX)
# path.separator Path separator (":" on UNIX)
# line.separator Line separator ("/n" on UNIX)
# user.name User's account name
# user.home User's home directory
# user.dir User's current working directory

複製代碼代碼如下:

# 對於getCanonicalPath()函數，「."就表示目前的資料夾，而」..「則表示目前資料夾的上一層資料夾
# 對於getAbsolutePath()函數，則不管”.”、“..”，返回當前的路徑加上你在new File()時設定的路徑
# 至於getPath()函數，得到的只是你在new File()時所設定的路徑

例如目前的路徑為C:/test ：
File directory = new File("abc");
directory.getCanonicalPath(); //得到的是C:/test/abc
directory.getAbsolutePath(); //得到的是C:/test/abc
direcotry.getPath(); //得到的是abc

File directory = new File(".");
directory.getCanonicalPath(); //得到的是C:/test
directory.getAbsolutePath(); //得到的是C:/test/.
direcotry.getPath(); //得到的是.

File directory = new File("..");
directory.getCanonicalPath(); //得到的是C:/
directory.getAbsolutePath(); //得到的是C:/test/..
direcotry.getPath(); //得到的是..