#yyds干货盘点#Spring专题「技术原理」为大家介绍一下Spring中的Ant路径匹配工具组件AntPathMatcher _工具组件

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Spring中的绝大多数的路径匹配规则是依照Ant的标准来的
【#yyds干货盘点#Spring专题「技术原理」为大家介绍一下Spring中的Ant路径匹配工具组件AntPathMatcher】实际上不只是SpringMVC，整个Spring框架的路径解析都是按照Ant的风格来的，在Spring中的具体实现,详情参见 org.springframework.util.AntPathMatcher，具体规则如下

/**
* @link PathMatcher implementation for Ant-style path patterns.
*
* Part of this mapping code has been kindly borrowed from < a href="http://ant.apache.org"> Apache Ant< /a> .
*
* The mapping matches URLs using the following rules: 
* < ul>
* < li> @code ? matches one character< /li>
* < li> @code * matches zero or more characters< /li>
* < li> @code ** matches zero or more directories in a path< /li>
* < li> @code spring:[a-z]+ matches the regexp @code [a-z]+ as a path variable named "spring"< /li>
* < /ul>
*
* < h3> Examples< /h3>
* < ul>
* < li> @code com/t?st.jsp & mdash; matches @code com/test.jsp but also
* @code com/tast.jsp or @code com/txst.jsp< /li>
* < li> @code com/*.jsp & mdash; matches all @code .jsp files in the
* @code com directory< /li>
* < li> < code> com/& #42; & #42; /test.jsp< /code> & mdash; matches all @code test.jsp
* files underneath the @code com path< /li>
* < li> < code> org/springframework/& #42; & #42; /*.jsp< /code> & mdash; matches all
* @code .jsp files underneath the @code org/springframework path< /li>
* < li> < code> org/& #42; & #42; /servlet/bla.jsp< /code> & mdash; matches
* @code org/springframework/servlet/bla.jsp but also
* @code org/springframework/testing/servlet/bla.jsp and @code org/servlet/bla.jsp< /li>
* < li> @code com/filename:\\\\w+.jsp will match @code com/test.jsp and assign the value @code test
* to the @code filename variable< /li>
* < /ul>
*
* Note: a pattern and a path must both be absolute or must
* both be relative in order for the two to match. Therefore it is recommended
* that users of this implementation to sanitize patterns in order to prefix
* them with "/" as it makes sense in the context in which theyre used.
* /

符号的规则定义标准

? 匹配1个字符
* 匹配0个或多个字符
** 匹配路径中的0个或多个目录
spring:[a-z]+ 将正则表达式[a-z]+匹配到的值，赋值给名为spring的路径变量。

必须是完全匹配才行，在SpringMVC中只有完全匹配才会进入controller层的方法
符号 ?和其它几个不一样的是? 要求必须为一个字符，并且不能是代表路径分隔符的/。

@RequestMapping("/index?")
@ResponseBody
public String index()
return "index.html";

结果

indexfalse 404错误(必须要有一个字符)
index/false 404错误(不能为"/")
indexabfalse 404错误(不能是多个字符)
indexatrue输出页面index.html
`

符号 *

，虽然可以匹配多个任意的字符，但是，无法用 * 可以替代 ** ，因为 * 代表的多个任意字符组成的字符串不能是个目录或者说路径.也就是说，* 并不能拿来替代 **.

示例代码:

@RequestMapping("/index*")
@ResponseBody
public String index()
return "index.html";

结果:

indextrue输出index.html(可以为0字符)
index/true输出 index.html(可以为"/")
indexatrue输出 index.html(可以为1个字符)
indexabctrue输出 index.html(可以为多个字符)
index/afalse 404错误("/a"是一个路径)
`

符号 **0个或多个目录.** 代表的字符串本身不一定要包含 /

@RequestMapping("/index/**/a")
@ResponseBody
public String index()
return "index.html";

结果:

index/atrue输出 index.html(可以为0个目录)
index/x/atrue输出 index.html(可以为一个目录)
index/x/z/c/atrue输出 index.html(可以为多个目录)
`

符号 spring:[a-z]+其它的关于 AntPathMatcher 的文章里,对 spring:[a-z]+ 的匹配大多是只字未提.这里补充下.示例代码:@RequestMapping("/index/username:[a-b]+") @ResponseBody public String index(@PathVariable("username") String username) System.out.println(username); return username; 结果:index/abtrue输出 ab index/abbaaatrue输出 abbaaa index/afalse 404错误 index/acfalse 404错误需求：我在做rbac权限校验的时候，设置管理员的访问路径为/admin/**,希望所有的开头为/admin/的uri操作地址都能进行匹配判断。
手动使用方式

AntPathMatcher不仅可以匹配Spring的@RequestMapping路径，也可以用来匹配各种字符串，包括文件路径等。
AntPathMatcher默认路径分隔符为“/”，而在匹配文件路径时，需要注意Windows下路径分隔符为“\\”，Linux下为“/”，写法即为：

初始化创建操作匹配文件路径，使用AntPathMatcher创建一个对象时，需要注意AntPathMatcher也有有参构造，传递路径分隔符参数pathSeparator，对于文件路径的匹配来说，则需要根据不同的操作系统来传递各自的文件分隔符，以此防止匹配文件路径错误。

AntPathMatcher matcher = new AntPathMatcher(File.separator)；
AntPathMatcher matcher = new AntPathMatcher(System.getProperty("file.separator"))；

执行匹配操作

import org.springframework.util.AntPathMatcher;
String content = "/admin/acuff";
String pattern = "/admin/**";
System.out.println(antPathMatcher.match(pattern, content));

最长匹配原则(has more characters)最长匹配规则（has more characters），即越精确的模式越会被优先匹配到。例如，URL请求/app/dir/file.jsp，现在存在两个路径匹配模式/**/*.jsp和/app/dir/*.jsp，那么会根据模式/app/dir/*.jsp来匹配。当然如果觉得这个工具还不够强大，还可以使用RegexRequestMatcher ，它支持使用正则表达式对URL地址进行匹配。如果你觉得这些都不够强大可以自己重写 RequestMatcher接口来进行定制的路由匹配规则
摘取网上的案例参考Sample

// test exact matching
assertTrue(pathMatcher.match("test", "test"));
assertTrue(pathMatcher.match("/test", "/test"));
assertTrue(pathMatcher.match("http://example.org", "http://example.org")); // SPR-14141
assertFalse(pathMatcher.match("/test.jpg", "test.jpg"));
assertFalse(pathMatcher.match("test", "/test"));
assertFalse(pathMatcher.match("/test", "test"));

// test matching with ?s
assertTrue(pathMatcher.match("t?st", "test"));
assertTrue(pathMatcher.match("??st", "test"));
assertTrue(pathMatcher.match("tes?", "test"));
assertTrue(pathMatcher.match("te??", "test"));
assertTrue(pathMatcher.match("?es?", "test"));
assertFalse(pathMatcher.match("tes?", "tes"));
assertFalse(pathMatcher.match("tes?", "testt"));
assertFalse(pathMatcher.match("tes?", "tsst"));

// test matching with *s
assertTrue(pathMatcher.match("*", "test"));
assertTrue(pathMatcher.match("test*", "test"));
assertTrue(pathMatcher.match("test*", "testTest"));
assertTrue(pathMatcher.match("test/*", "test/Test"));
assertTrue(pathMatcher.match("test/*", "test/t"));
assertTrue(pathMatcher.match("test/*", "test/"));
assertTrue(pathMatcher.match("*test*", "AnothertestTest"));
assertTrue(pathMatcher.match("*test", "Anothertest"));
assertTrue(pathMatcher.match("*.*", "test."));
assertTrue(pathMatcher.match("*.*", "test.test"));
assertTrue(pathMatcher.match("*.*", "test.test.test"));
assertTrue(pathMatcher.match("test*aaa", "testblaaaa"));
assertFalse(pathMatcher.match("test*", "tst"));
assertFalse(pathMatcher.match("test*", "tsttest"));
assertFalse(pathMatcher.match("test*", "test/"));
assertFalse(pathMatcher.match("test*", "test/t"));
assertFalse(pathMatcher.match("test/*", "test"));
assertFalse(pathMatcher.match("*test*", "tsttst"));
assertFalse(pathMatcher.match("*test", "tsttst"));
assertFalse(pathMatcher.match("*.*", "tsttst"));
assertFalse(pathMatcher.match("test*aaa", "test"));
assertFalse(pathMatcher.match("test*aaa", "testblaaab"));

// test matching with ?s and /s
assertTrue(pathMatcher.match("/?", "/a"));
assertTrue(pathMatcher.match("/?/a", "/a/a"));
assertTrue(pathMatcher.match("/a/?", "/a/b"));
assertTrue(pathMatcher.match("/??/a", "/aa/a"));
assertTrue(pathMatcher.match("/a/??", "/a/bb"));
assertTrue(pathMatcher.match("/?", "/a"));

// test matching with s
assertTrue(pathMatcher.match("/ ", "/testing/testing"));
assertTrue(pathMatcher.match("/*/ ", "/testing/testing"));
assertTrue(pathMatcher.match("/ /*", "/testing/testing"));
assertTrue(pathMatcher.match("/bla/ /bla", "/bla/testing/testing/bla"));
assertTrue(pathMatcher.match("/bla/ /bla", "/bla/testing/testing/bla/bla"));
assertTrue(pathMatcher.match("/ /test", "/bla/bla/test"));
assertTrue(pathMatcher.match("/bla/ /**/bla", "/bla/bla/bla/bla/bla/bla"));
assertTrue(pathMatcher.match("/bla*bla/test", "/blaXXXbla/test"));
assertTrue(pathMatcher.match("/*bla/test", "/XXXbla/test"));
assertFalse(pathMatcher.match("/bla*bla/test", "/blaXXXbl/test"));
assertFalse(pathMatcher.match("/*bla/test", "XXXblab/test"));
assertFalse(pathMatcher.match("/*bla/test", "XXXbl/test"));

assertFalse(pathMatcher.match("/????", "/bala/bla"));
assertFalse(pathMatcher.match("/**/*bla", "/bla/bla/bla/bbb"));

assertTrue(pathMatcher.match("/*bla*/ /bla/ ", "/XXXblaXXXX/testing/testing/bla/testing/testing/"));
assertTrue(pathMatcher.match("/*bla*/**/bla/*", "/XXXblaXXXX/testing/testing/bla/testing"));
assertTrue(pathMatcher.match("/*bla*/ /bla/ ", "/XXXblaXXXX/testing/testing/bla/testing/testing"));
assertTrue(pathMatcher.match("/*bla*/ /bla/ ", "/XXXblaXXXX/testing/testing/bla/testing/testing.jpg"));

assertTrue(pathMatcher.match("*bla*/ /bla/ ", "XXXblaXXXX/testing/testing/bla/testing/testing/"));
assertTrue(pathMatcher.match("*bla*/**/bla/*", "XXXblaXXXX/testing/testing/bla/testing"));
assertTrue(pathMatcher.match("*bla*/ /bla/ ", "XXXblaXXXX/testing/testing/bla/testing/testing"));
assertFalse(pathMatcher.match("*bla*/**/bla/*", "XXXblaXXXX/testing/testing/bla/testing/testing"));

assertFalse(pathMatcher.match("/x/x/ /bla", "/x/x/x/"));

assertTrue(pathMatcher.match("/foo/bar/ ", "/foo/bar")) ;

assertTrue(pathMatcher.match("", ""));

assertTrue(pathMatcher.match("/bla.*", "/testing.html"));
`

spring mvc url地址匹配工具类
AntPathRequestMatcher在spring mvc 中我们会经常使用//*.jsp、/app//dir/file.、/**/example 、/app/*.x 类似于这样语法而负责真正判断是否匹配的工具类就是AntPathRequestMatcher