Java 用于重写URL的servlet筛选器

我正在尝试从以下位置重写URL：

• localhost:8080/sendmail/newEmail.pdf？请求id=23456&emailAddress=

致：

• localhost:8080/sendmail/newEmail.pdf？请求\u id=23456

下面是筛选器类代码和映射。我怎样才能完成这项任务？（请给出一个例子，不胜感激）

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>

---

我建议使用现有的实现，而不是自己编写

似乎有一个Java URL重写实现，即Tuckey的URLRewiteFilter

见：

这应该是你想要的，还有更多

或者，如果您在web容器前面使用apache，您可能需要查看

mod_rewrite

，它在apache上执行相同的操作

---

如果您真正需要的只是这一个简单的URL清理，那么使用正则表达式或URL重写模块可能会有些过火

一个完全简单的实现可能是这样的：

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);
        }
    }
}

---

使用

org.springframework.mock.web.*

类可以轻松地对其进行单元测试：

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());
    }
}

---

我理解重新发明轮子的不情愿，但我不相信有人会认为在servlet容器前面添加Apache只是为了重写URL比创建一个简单的过滤器和几行代码要好。@stepanian是的，那太过分了，这就是为什么我首先建议使用Java解决方案，并说如果前面已经有了apache（无论出于何种原因），mod_rewrite可能是一种替代方法。

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());
    }
}