基于Ant路径匹配规则AntPathMatcher的注意事项

目录

• AntPathMatcher前言
• 基本规则
• 注意事项
• 测试用例
• spring url匹配工具类----AntPathMatcher
• 具体使用场景
• 请求body的二次写入

AntPathMatcher前言

（1）SpringMVC的路径匹配规则是依照Ant的来的，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；

（2）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。

基本规则

（1）? 匹配一个字符（除过操作系统默认的文件分隔符）

（2）* 匹配0个或多个字符

（3）**匹配0个或多个目录

（4）{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.

(PS: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)

注意事项

（1）匹配文件路径，需要匹配某目录下及其各级子目录下所有的文件，使用/**/*而非*.*，因为有的文件不一定含有文件后缀；

（2）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。源码截图如下：

可以看到，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：

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

（3）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。

测试用例

    // 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 url匹配工具类----AntPathMatcher

在gateway进行授权认证时，有些请求url需要过滤掉，针对带/service/{id}/user-info这种带操作符的请求，需要特殊处理----AntPathMatcher就上场啦

具体使用场景

1.登录授权验证：过滤掉登录请求，一些资源获取请求

2.请求接口日志打印：过滤掉文件上传和下载的一些请求，requestBody里的文件流会被异常修改

具体代码：

请求body的二次写入

@Component
public class CachePostBodyFilter implements GlobalFilter, Ordered {
    private final List<HttpMessageReader<?>> messageReaders;
    public CachePostBodyFilter() {
        this.messageReaders = HandlerStrategies.withDefaults().messageReaders();
    }
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
        if (FilterUrl.excludeUrls(new FilterUrl(request.getPath().toString(), request.getMethod()))) {
            return chain.filter(exchange);
        }
        if (Objects.equals(request.getMethod(), HttpMethod.POST)) {
            ServerRequest serverRequest = ServerRequest.create(exchange,
                    messageReaders);
            Mono<String> modifiedBody = serverRequest.bodyToMono(String.class)
                    .flatMap(body -> {
                        exchange.getAttributes().put(RequestConstants.REQUEST_BODY, body);
                        return Mono.just(body);
                    });
            BodyInserter bodyInserter = BodyInserters.fromPublisher(modifiedBody, String.class);
            HttpHeaders headers = new HttpHeaders();
            headers.putAll(exchange.getRequest().getHeaders());
            // the new content type will be computed by bodyInserter
            // and then set in the request decorator
            headers.remove(HttpHeaders.CONTENT_LENGTH);
            CachedBodyOutputMessage outputMessage = new CachedBodyOutputMessage(exchange, headers);
            return bodyInserter.insert(outputMessage, new BodyInserterContext()).
                    then(Mono.defer(() -> {
                        ServerHttpRequest decorator = decorate(exchange, headers,
                                outputMessage);
                        return chain.filter(exchange.mutate().request(decorator).build());
                    }));
        }
        return chain.filter(exchange);
    }
    ServerHttpRequestDecorator decorate(ServerWebExchange exchange, HttpHeaders headers,
            CachedBodyOutputMessage outputMessage) {
        return new ServerHttpRequestDecorator(exchange.getRequest()) {
            @Override
            public HttpHeaders getHeaders() {
                long contentLength = headers.getContentLength();
                HttpHeaders httpHeaders = new HttpHeaders();
                httpHeaders.putAll(headers);
                if (contentLength > 0) {
                    httpHeaders.setContentLength(contentLength);
                } else {
                    httpHeaders.set(HttpHeaders.TRANSFER_ENCODING, "chunked");
                }
                return httpHeaders;
            }
            @Override
            public Flux<DataBuffer> getBody() {
                return outputMessage.getBody();
            }
        };
    }
    @Override
    public int getOrder() {
        return -8;
    }
}

@Data
@NoArgsConstructor
@AllArgsConstructor
public class FilterUrl {
    private String url;
    private HttpMethod method;
    public static boolean excludeUrls(FilterUrl targetUrl) {
        List<FilterUrl> excludeUrls = Lists.newArrayList();
        excludeUrls.add(new FilterUrl("/api/v1/service/users", HttpMethod.POST));
        excludeUrls.add(new FilterUrl("/api/v1/service/terms/{termId}/export", HttpMethod.GET));
        AntPathMatcher antPathMatcher = new AntPathMatcher();
        return excludeUrls.stream()
                .anyMatch(url -> antPathMatcher.match(url.getUrl(), targetUrl.getUrl()) && url.getMethod().equals(targetUrl.getMethod()));
    }
}

以上为个人经验，希望能给大家一个参考，也希望大家多多支持我们。