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[Java教程]Spring源码解析


最近在看SpringMVC的源码,发现request分发时,路径匹配最后是委托给AntPathMatcher实现的.索性看看吧.

文章摘要:

  1. ant匹配规则

  2. PathMatcher接口

  3. 通过测试用例看AntPathMatcher的使用

 

ant匹配规则

AntPathMatcher如名使用的ant 的匹配规则,我们先看看吧.

  字符wildcard    描述

   ?         匹配一个字符

   *         匹配0个及以上字符

   **         匹配0个及以上目录directories

看几个官方的例子吧:

  com/t?st.jsp -             匹配: com/test.jsp  ,  com/tast.jsp  ,  com/txst.jsp
  com/*.jsp -             匹配: com文件夹下的全部.jsp文件
  com/**/test.jsp -          匹配: com文件夹和子文件夹下的全部.jsp文件,
  org/springframework/**/*.jsp -    匹配: org/springframework文件夹和子文件夹下的全部.jsp文件
  org/**/servlet/bla.jsp -       匹配: org/springframework/servlet/bla.jsp  ,  org/springframework/testing/servlet/bla.jsp  ,  org/servlet/bla.jsp

 

PathMatcher接口

主要是判断是否匹配pattern,并解析出path中的参数

 1 package org.springframework.util; 2  3 public interface PathMatcher { 4  5   /** 6    * 判断传入的path是否可以作为pattern使用 7   */ 8   boolean isPattern(String path); 9 10   /**11    * 使用pattern匹配path12   */13   boolean match(String pattern, String path);14 15   /**16    * 如名,是否开始部分匹配17   */18   boolean matchStart(String pattern, String path);19 20   /**21    * 提取path中匹配到的部分,如pattern(myroot/*.html),path(myroot/myfile.html),返回myfile.html22   */23   String extractPathWithinPattern(String pattern, String path);24 25   /**26    * 提取path中匹配到的部分,只是这边还需跟占位符配对为map,27    * 如pattern(/hotels/{hotel}),path(/hotels/1),解析出"hotel"->"1"28   */29   Map<String, String> extractUriTemplateVariables(String pattern, String path);30 31   /**32    * 提供比较器33   */34   Comparator<String> getPatternComparator(String path);35 36   /**37    * 合并pattern,pattern1然后pattern238   */39   String combine(String pattern1, String pattern2);40 41 }

 

 

通过测试用例看AntPathMatcher的使用

一看测试用例,瞬间服了,人家开发真是规范.

人家整这么规范,还是有空直接看源码好了.这边挑几个简单的例子看看就好

1. match 跟 matchStart 的差异,这个我们在测试用例看下面的情况会比较明确

  这边的代码,我截取了一小部分

 1 package org.springframework.util; 2 public class AntPathMatcherTests { 3   @Test 4   public void match() { 5     // ... 6     assertFalse(pathMatcher.match("/x/x/**/bla", "/x/x/x/")); 7     // ... 8   } 9   @Test10   public void withMatchStart() {11     // ...12     assertTrue(pathMatcher.matchStart("/x/x/**/bla", "/x/x/x/"));13     // ...14   }15 }

 

2. extractPathWithinPattern,代码很清楚,不废话

 1 package org.springframework.util; 2 public class AntPathMatcherTests { 3   @Test 4   public void extractPathWithinPattern() throws Exception { 5     // ... 6     assertEquals("", pathMatcher.extractPathWithinPattern("/docs/commit.html", "/docs/commit.html")); 7     assertEquals("cvs/commit", pathMatcher.extractPathWithinPattern("/docs/*", "/docs/cvs/commit")); 8     assertEquals("docs/cvs/commit", pathMatcher.extractPathWithinPattern("/d?cs/*", "/docs/cvs/commit")); 9     // ...10   }11 }

3. extractUriTemplateVariables

 1 package org.springframework.util; 2 public class AntPathMatcherTests { 3   @Test 4   public void extractUriTemplateVariables() throws Exception { 5     Map<String, String> result = pathMatcher.extractUriTemplateVariables("/hotels/{hotel}", "/hotels/1"); 6     assertEquals(Collections.singletonMap("hotel", "1"), result); 7     // ... 8     result = pathMatcher.extractUriTemplateVariables("/{page}.*", "/42.html"); 9     assertEquals(Collections.singletonMap("page", "42"), result);10     // ...11   }12   /**13    * SPR-778714   */15   @Test16   public void extractUriTemplateVarsRegexQualifiers() {17     Map<String, String> result = pathMatcher.extractUriTemplateVariables(18         "{symbolicName:[\\p{L}\\.]+}-sources-{version:[\\p{N}\\.]+}.jar",19         "com.example-sources-1.0.0.jar");20     assertEquals("com.example", result.get("symbolicName"));21     assertEquals("1.0.0", result.get("version"));22     // ...23   }24 }

4. combine

 1 package org.springframework.util; 2 public class AntPathMatcherTests { 3   @Test 4   public void combine() { 5     // ... 6     assertEquals("/hotels", pathMatcher.combine("/hotels", null)); 7     assertEquals("/hotels/booking", pathMatcher.combine("/hotels/*", "/booking")); 8     assertEquals("/hotels/**/booking", pathMatcher.combine("/hotels/**", "booking")); 9     assertEquals("/hotels/**/booking", pathMatcher.combine("/hotels/**", "/booking"));10     assertEquals("/hotels/booking", pathMatcher.combine("/hotels", "/booking"));11     assertEquals("/hotels/{hotel}", pathMatcher.combine("/hotels/*", "{hotel}"));12     assertEquals("/hotels/**/{hotel}", pathMatcher.combine("/hotels/**", "{hotel}"));13     assertEquals("/hotels/*/booking/{booking}", pathMatcher.combine("/hotels/*/booking", "{booking}"));14   }15 }