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。
public void testUniqueServiceName() throws Exception {
        ServiceBuilder<Greeting> builder = new ServiceBuilder<>();
        builder.group("dubbo").interfaceClass(Greeting.class).version("1.0.0");
        ServiceConfig<Greeting> service = builder.build();
        assertThat(service.getUniqueServiceName(), equalTo("dubbo/" + Greeting.class.getName() + ":1.0.0"));
    }
    @Test
    void path() {
        ServiceBuilder builder = new ServiceBuilder();
        builder.path("path");
        Assertions.assertEquals("path", builder.build().getPath());
    }
    @Test
    void addMethod() {
        MethodConfig method = new MethodConfig();
        ServiceBuilder builder = new ServiceBuilder();
        builder.addMethod(method);
        Assertions.assertTrue(builder.build().getMethods().contains(method));
        Assertions.assertEquals(1, builder.build().getMethods().size());
    }
    @Test
    void addMethods() {
        MethodConfig method = new MethodConfig();
        ServiceBuilder builder = new ServiceBuilder();
        builder.addMethods(Collections.singletonList(method));
        Assertions.assertTrue(builder.build().getMethods().contains(method));
        Assertions.assertEquals(1, builder.build().getMethods().size());
    }
    @Test
    void provider() {