热门文章
 当前位置：技术文章 > 编程面试题 >

使用Spring MockMVC测试可选路径变量

问题内容：

我在Spring MVC中有一个带有可选path变量的方法。我正在尝试在未提供可选路径变量的情况下对其进行测试。

来自Controller的代码段，用于调用-的资源URI

@RequestMapping(value = "/some/uri/{foo}/{bar}", method = RequestMethod.PUT)
public <T> ResponseEntity<T> someMethod(@PathVariable("foo") String foo, @PathVariable(value = "bar", required = false) String bar) {

    LOGGER.info("foo: {}, bar: {}", foo, bar);
}

我使用MockMvc-进行测试的片段

//inject context
@Autowired
private WebApplicationContext webApplicationContext;

protected MockMvc mockMvc;

@Before
public void setup() {
    //build mockMvc
    mockMvc = MockMvcBuilders.webAppContextSetup(webApplicationContext).build();
}

@Test
public void someMethodTest() throws Exception {
    //works as expected
    mockMvc.perform(put("/some/uri/{foo}/{bar}", "foo", "bar"))
            .andExpect(status().isOk()); //works

    //following doesn't work

    //pass null for optional
    mockMvc.perform(put("/some/uri/{foo}/{bar}", "foo", null))
            .andExpect(status().isOk()); //throws 404

    //pass empty for optional
    mockMvc.perform(put("/some/uri/{foo}/{bar}", "foo", ""))
            .andExpect(status().isOk()); //throws 404

    //remove optional from URI
    mockMvc.perform(put("/some/uri/{foo}", "foo"))
            .andExpect(status().isOk()); //throws 404
}

问题答案：

使用这样的@RequestMapping值数组…

@RequestMapping(value = {"/some/uri/{foo}", "/some/uri/{foo}/{bar}"}, method = RequestMethod.PUT)
public ResponseEntity<String> someMethod(@PathVariable("foo") String foo, @PathVariable(value = "bar", required = false) String bar) {
    return new ResponseEntity<>(foo + " and " + (bar == null ? "<null>" : bar), HttpStatus.OK);
}

…将使该测试通过：

@Test
public void someMethodTest() throws Exception {
    MvcResult mvcResult = mockMvc.perform(put("/some/uri/{foo}/{bar}", "foo", "bar"))
            .andExpect(status().isOk()).andReturn();
    Assert.assertEquals("foo and bar", mvcResult.getResponse().getContentAsString());

    mvcResult = mockMvc.perform(put("/some/uri/{foo}/{bar}", "foo", null))
            .andExpect(status().isOk()).andReturn();
    Assert.assertEquals("foo and <null>", mvcResult.getResponse().getContentAsString());

    mvcResult = mockMvc.perform(put("/some/uri/{foo}/{bar}", "foo", ""))
            .andExpect(status().isOk()).andReturn();
    Assert.assertEquals("foo and <null>", mvcResult.getResponse().getContentAsString());

    mvcResult = mockMvc.perform(put("/some/uri/{foo}", "foo"))
            .andExpect(status().isOk()).andReturn();
    Assert.assertEquals("foo and <null>", mvcResult.getResponse().getContentAsString());
}

当然，这似乎是最简单的解决方案，并且它对Swagger之类的工具可能更友好，因为它使映射变得明确。

但是，您也可以声明一个通配符映射，然后在控制器方法中使用路径匹配器来解释请求URI。例如，此方法…

private final AntPathMatcher antPathMatcher = new AntPathMatcher();

@RequestMapping(value = "/some/uri/with/wildcards/**", method = RequestMethod.PUT)
public ResponseEntity<String> someMethod(HttpServletRequest request) {
    String matched = antPathMatcher.extractPathWithinPattern(
            (String) request.getAttribute(HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE), request.getPathInfo());
    // ugly parsing code to read the path variables, allowing for the optionality of the second one
    String foo = matched;
    String bar = null;
    String[] pathVariables = matched.split("/");
    if (pathVariables.length > 1) {
        foo = pathVariables[0];
        bar = pathVariables[1];
    }
    return new ResponseEntity<>(foo + " and " + (bar == null ? "<null>" : bar), HttpStatus.OK);
}

…将使该测试通过：

@Test
public void someMethodTestWithWildcards() throws Exception {
    MvcResult mvcResult = mockMvc.perform(put("/some/uri/with/wildcards/{foo}/{bar}", "foo", "bar"))
            .andExpect(status().isOk()).andReturn();
    Assert.assertEquals("foo and bar", mvcResult.getResponse().getContentAsString());

    mvcResult = mockMvc.perform(put("/some/uri/with/wildcards/{foo}/{bar}", "foo", null))
            .andExpect(status().isOk()).andReturn();
    Assert.assertEquals("foo and <null>", mvcResult.getResponse().getContentAsString());

    mvcResult = mockMvc.perform(put("/some/uri/with/wildcards/{foo}/{bar}", "foo", ""))
            .andExpect(status().isOk()).andReturn();
    Assert.assertEquals("foo and <null>", mvcResult.getResponse().getContentAsString());

    mvcResult = mockMvc.perform(put("/some/uri/with/wildcards/{foo}", "foo"))
            .andExpect(status().isOk()).andReturn();
    Assert.assertEquals("foo and <null>", mvcResult.getResponse().getContentAsString());
}