翻译积累 - Java 正则表达式 Pattern 类

翻译内容选自: java.util.regex.Pattern.java(JDK8)

目的: 学习源码, 顺带积累英文阅读感觉.

A compiled representation of a regular expression.

正则表达式的编译表示。

A regular expression, specified as a string, must first be compiled into an instance of this class.

必须首先将指定为字符串的正则表达式编译到此类的实例中

The resulting pattern can then be used to create a Matcher object that can match arbitrary character sequences against the regular expression.

然后，可以使用生成的模式创建匹配器对象，该对象可以根据正则表达式匹配任意字符序列。

All of the state involved in performing a match resides in the matcher, so many matchers can share the same pattern.

执行匹配所涉及的所有状态都驻留在匹配器中，因此许多匹配器可以共享相同的模式。

A typical invocation sequence is thus

因此，一个典型的调用序列是

Pattern p = Pattern.compile("a*b");

Matcher m = p.matcher("aaaaab");

boolean b = m.matches();

A matches method is defined by this class as a convenience for when a regular expression is used just once.

当正则表达式只使用一次时，该类将 matches 方法定义为方便。

This method compiles an expression and matches an input sequence against it in a single invocation.

这个方法编译一个表达式，并在一次调用中根据它匹配一个输入序列。

boolean b = Pattern.matches("a*b", "aaaaab");

The statement is equivalent to the three statements above, though for repeated matches it is less efficient since it does not allow the compiled pattern to be reused.

该声明等同于上述三个步骤, 尽管对于重复匹配，它的效率较低，因为它不允许重用编译后的模式。

Instances of this class are immutable and are safe for use by multiple concurrent threads.

此类的实例是不可变的，可供多个并发线程安全使用。

Instances of the Matcher class are not safe for such use.

Matcher 类的实例对于这种使用是不安全的。