2.7.0版本getContextPath方法：
```
protected String getContextPath(URL url) {
        String contextPath = url.getPath();
        return contextPath.endsWith("/") ? contextPath.substring(0,contextPath.length()-1) : contextPath;
    }
```
无法将方法置入web容器中，退回2.6.5版本的方法：
```
protected String getContextPath(URL url) {
        int pos = url.getPath().lastIndexOf("/");
        return pos > 0 ? url.getPath().substring(0, pos) : "";
    }
```
使用正常，两个方法应该不等价的。
assertNull(url.getPassword());
        assertEquals("10.20.130.230", url.getHost());
        assertEquals(20880, url.getPort());
        assertEquals("context/path", url.getPath());
        assertEquals(0, url.getParameters().size());
        url = URL.valueOf("admin:hello1234@10.20.130.230:20880/context/path?version=1.0.0&application=morgan");
        assertNull(url.getProtocol());
        assertEquals("admin", url.getUsername());
        assertEquals("hello1234", url.getPassword());
        assertEquals("10.20.130.230", url.getHost());
        assertEquals(20880, url.getPort());
        assertEquals("context/path", url.getPath());
        assertEquals(2, url.getParameters().size());
        assertEquals("1.0.0", url.getParameter("version"));
        assertEquals("morgan", url.getParameter("application"));
    }
    @Test
    public void test_valueOf_noHost() throws Exception {
        URL url = URL.valueOf("file:///home/user1/router.js");
        assertEquals("file", url.getProtocol());
        assertNull(url.getUsername());
        assertNull(url.getPassword());
        assertNull(url.getHost());
        assertEquals(0, url.getPort());
        assertEquals("home/user1/router.js", url.getPath());
        assertEquals(0, url.getParameters().size());
        
        url = URL.valueOf("file://home/user1/router.js");
        
        assertEquals("file", url.getProtocol());