Spring REST Docs: how to replace parameters

问题

In my unit tests we find

this.mockMvc
  .perform(post("/authenticate")
    .contentType(MediaType.APPLICATION_FORM_URLENCODED)
    .param("username", "user@example.com")
    .param("password", "superSecretPassword"))
  .andExpect(status().isOk())
  .andDo(document("preprocessed-request",
    preprocessRequest(replacePattern(Pattern.compile("superSecretPassword"), "XXX"))));

cf. Spring REST Docs documentation

This generates build/generated-snippets/preprocessed-request/http-request.adoc with the content

[source,http]
----
POST /authenticate HTTP/1.1
Content-Type: application/x-www-form-urlencoded

username=user%40example.com&password=superSecretPassword
----

But I expect the password to be masked because of replacePattern():

[source,http]
----
POST /authenticate HTTP/1.1
Content-Type: application/x-www-form-urlencoded

username=user%40example.com&password=XXX
----

What can I do?

回答1:

The pattern replacement has no effect due to an unfortunate side-effect of how MockMvc handles request parameters. replacePattern acts on the content, i.e. body of the request, but MockMvc doesn't actually include the form-encoded parameters in the body.

Spring REST Docs is smart enough to deal with this when it's generating the snippets, e.g. for a form URL encoded POST request it looks at the parameters to figure out what the request's body should be. It doesn't apply these same smarts when applying replacePattern.

You can still mask the password by using your own OperationPreprocessor that changes the parameter map. For example:

private OperationPreprocessor maskPassword() {
    return new PasswordMaskingPreprocessor();
}

private static class PasswordMaskingPreprocessor implements OperationPreprocessor {

    @Override
    public OperationRequest preprocess(OperationRequest request) {
        Parameters parameters = new Parameters();
        parameters.putAll(request.getParameters());
        parameters.set("password", "XXX");
        return new OperationRequestFactory().create(request.getUri(),
                request.getMethod(), request.getContent(), request.getHeaders(),
                parameters, request.getParts());
    }

    @Override
    public OperationResponse preprocess(OperationResponse response) {
        return response;
    }

}

You can then use this new preprocessor in place of replacePattern:

this.mockMvc
  .perform(post("/authenticate")
    .contentType(MediaType.APPLICATION_FORM_URLENCODED)
    .param("username", "user@example.com")
    .param("password", "superSecretPassword"))
  .andExpect(status().isOk())
  .andDo(document("preprocessed-request",
    preprocessRequest(maskPassword())));

来源：https://stackoverflow.com/questions/33281509/spring-rest-docs-how-to-replace-parameters