The Java Tutorials have been written for JDK 8.Java教程是为JDK 8编写的。Examples and practices described in this page don't take advantage of improvements introduced in later releases and might use technology no longer available.本页中描述的示例和实践没有利用后续版本中引入的改进，并且可能使用不再可用的技术。See Java Language Changes for a summary of updated language features in Java SE 9 and subsequent releases.有关Java SE 9及其后续版本中更新的语言特性的摘要，请参阅Java语言更改。
See JDK Release Notes for information about new features, enhancements, and removed or deprecated options for all JDK releases.有关所有JDK版本的新功能、增强功能以及已删除或不推荐的选项的信息，请参阅JDK发行说明。
An SDP configuration file is a text file, and you decide where on the file system this file will reside. Every line in the configuration file is either a comment or a rule. A comment is indicated by the hash character (#) at the beginning of the line, and everything following the hash character will be ignored.
There are two types of rules, as follows:
A rule has the following form:
("bind"|"connect")1*LWSP-char(hostname|ipaddress)["/"prefix])1*LWSP-char("*"|port)["-"("*"|port)]1*LWSP-char means that any number of linear whitespace characters (tabs or spaces) can separate the tokens. The square brackets indicate optional text. The notation (xxx | yyy) indicates that the token will include either xxx or yyy, but not both. Quoted characters indicate literal text.
The first keyword indicates whether the rule is a bind or a connect rule. The next token specifies either a host name or a literal IP address. When you specify a literal IP address, you can also specify a prefix, which indicates an IP address range. The third and final token is a port number or a range of port numbers.
Consider the following notation in this sample configuration file:
# Use SDP when binding to 192.0.2.1 bind 192.0.2.1 * # Use SDP when connecting to all application services on 192.0.2.* connect 192.0.2.0/24 1024-* # Use SDP when connecting to the http server or a database on examplecluster connect examplecluster.example.com 80 connect examplecluster.example.com 3306
The first rule in the sample file specifies that SDP is used for any port (*) on the local IP address 192.0.2.1. You would add a bind rule for each local address assigned to an InfiniBand adaptor. (An InfiniBand adaptor is the equivalent of a network interface card (NIC) for InfiniBand.) If you had several IB adaptors, you would use a bind rule for each address that is assigned to those adaptors.
The second rule in the sample file specifies that whenever connecting to 192.0.2.* and the target port is 1024 or greater, SDP is used. The prefix on the IP address /24 indicates that the first 24 bits of the 32-bit IP address should match the specified address. Each portion of the IP address uses 8 bits, so 24 bits indicates that the IP address should match 192.0.2 and the final byte can be any value. The -* notation on the port token specifies "and above." A range of ports, such as 1024—2056, would also be valid and would include the end points of the specified range.
The final rules in the sample file specify a host name (examplecluster), first with the port assigned to an http server (80) and then with the port assigned to a database (3306). Unlike a literal IP address, a host name can translate into multiple addresses. When you specify a host name, it matches all addresses that the host name is registered to in the name service.