Servlet过滤器重写URL(servlet filter to rewrite URL)

我试图从重写URL：

• localhost:8080/sendEmail/newEmail.pdf?request_id=23456&emailAddress=

至：

• localhost:8080/sendEmail/newEmail.pdf?request_id=23456

过滤器类代码和映射如下。 我怎样才能完成这个任务？ （用一个例子的回答将高度赞赏）。

过滤器映射：

<filter>
    <filter-name>RequestFilter</filter-name>
    <filter-class>com.abc.ms.email.filter.RequestFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>RequestFilter</filter-name>
    <url-pattern>/*</url-pattern>
    <dispatcher>REQUEST</dispatcher>
    <dispatcher>FORWARD</dispatcher>
</filter-mapping>

过滤器的代码：

public class RequestFilter implements Filter {
    private static final Pattern REWRITE_PATTERN = Pattern.compile("(^[1-9]\\d*)$");

    public void doFilter(ServletRequest req, ServletResponse res, FilterChain fc) throws IOException, ServletException {
        HttpServletRequestWrapper wrapper = new HttpServletRequestWrapper((HttpServletRequest)req);
        String url = wrapper.getRequestURL().toString();
        String number = url.substring(url.lastIndexOf("/")).replace("/", "");
        Matcher m = REWRITE_PATTERN.matcher(number);
        if (m.find()) {
            RequestDispatcher dispatcher = wrapper.getRequestDispatcher("request?id=" + m.group(1));
            dispatcher.forward(req, res);
        } else {
            fc.doFilter(wrapper, res);
        }
    }
}

Answer 1:

我会建议使用现有的实现，而不是你自己写的。

似乎是一个 Java的URL重写实现，这是Tuckey的URLrewriteFilter。

请参阅： http://tuckey.org/urlrewrite/

这应该做你想要什么，以及更多。

另外，如果你在你的Web容器的前面使用Apache，你可能要考虑mod_rewrite ，它做同样在Apache。

http://httpd.apache.org/docs/current/mod/mod_rewrite.html

Answer 2:

如果你真正需要的是这一个简单的URL清理，然后使用正则表达式或URL重写模块可能矫枉过正。

一个完全简单的实现可能会去是这样的：

public class RequestFilter implements Filter {

    private static final String LOOK_FOR = "sendEmail/newEmail.pdf";

    private static final String REMOVE = "&emailAddress=";

    public void doFilter(ServletRequest req, ServletResponse res, FilterChain fc) throws IOException, ServletException {
        HttpServletRequestWrapper wrapper = new HttpServletRequestWrapper((HttpServletRequest)req);
        String original = wrapper.getRequestURL().toString();
        if(original.contains(LOOK_FOR)) {
            String filtered = StringUtils.substringBeforeLast(original, REMOVE);
            RequestDispatcher dispatcher = wrapper.getRequestDispatcher(filtered);
            dispatcher.forward(req, res);
        } else {
            fc.doFilter(wrapper, res);
        }
    }
}

---

这是很容易单元，使用测试org.springframework.mock.web.*类：

public class RequestFilterTest {

    private RequestFilter filter;

    @Before
    public void setUp() {
        filter = new RequestFilter();
    }

    @Test
    public void testRedirect() throws IOException, ServletException {
        MockHttpServletRequest request  = new MockHttpServletRequest("GET",
                "/sendEmail/newEmail.pdf?request_id=23456&emailAddress=");
        MockHttpServletResponse response = new MockHttpServletResponse();
        MockFilterChain fc = new MockFilterChain();

        filter.doFilter(request , response, fc);

        Assert.assertEquals("http://localhost:80/sendEmail/newEmail.pdf?request_id=23456", response.getForwardedUrl());
    }
}

文章来源: servlet filter to rewrite URL