Volley - 如何发送 DELETE 请求参数？

Question

我正在尝试使用 Volley 向我的服务器发送 DELETE 类型的请求，并向请求中添加参数。到目前为止，我还不能这样做。

创建自定义请求并覆盖 getParams() 方法对我没有帮助，因为不会为 DELETE 类型请求调用此方法。

如何在 Volley 中为 DELETE 请求添加参数？

Answer 1

同样的问题，但我找到了解决方案。

问题在于 com.android.volley.toolbox.HttpClientStack.java 中 createHttpRequest 方法的实现，只有当请求方法是 POST、PUT 或 PATCH 时才会添加正文。

/**
 * Creates the appropriate subclass of HttpUriRequest for passed in request.
 */
@SuppressWarnings("deprecation")
/* protected */ static HttpUriRequest createHttpRequest(Request<?> request,
        Map<String, String> additionalHeaders) throws AuthFailureError {
    switch (request.getMethod()) {
        case Method.DEPRECATED_GET_OR_POST: {
            // This is the deprecated way that needs to be handled for backwards compatibility.
            // If the request's post body is null, then the assumption is that the request is
            // GET.  Otherwise, it is assumed that the request is a POST.
            byte[] postBody = request.getPostBody();
            if (postBody != null) {
                HttpPost postRequest = new HttpPost(request.getUrl());
                postRequest.addHeader(HEADER_CONTENT_TYPE, request.getPostBodyContentType());
                HttpEntity entity;
                entity = new ByteArrayEntity(postBody);
                postRequest.setEntity(entity);
                return postRequest;
            } else {
                return new HttpGet(request.getUrl());
            }
        }
        case Method.GET:
            return new HttpGet(request.getUrl());
        case Method.DELETE:
            return new HttpDelete(request.getUrl());
        case Method.POST: {
            HttpPost postRequest = new HttpPost(request.getUrl());
            postRequest.addHeader(HEADER_CONTENT_TYPE, request.getBodyContentType());
            setEntityIfNonEmptyBody(postRequest, request);
            return postRequest;
        }
        case Method.PUT: {
            HttpPut putRequest = new HttpPut(request.getUrl());
            putRequest.addHeader(HEADER_CONTENT_TYPE, request.getBodyContentType());
            setEntityIfNonEmptyBody(putRequest, request);
            return putRequest;
        }
        case Method.HEAD:
            return new HttpHead(request.getUrl());
        case Method.OPTIONS:
            return new HttpOptions(request.getUrl());
        case Method.TRACE:
            return new HttpTrace(request.getUrl());
        case Method.PATCH: {
            HttpPatch patchRequest = new HttpPatch(request.getUrl());
            patchRequest.addHeader(HEADER_CONTENT_TYPE, request.getBodyContentType());
            setEntityIfNonEmptyBody(patchRequest, request);
            return patchRequest;
        }
        default:
            throw new IllegalStateException("Unknown request method.");
    }
}

所以你必须使用你自己的 HttpStack.java 实现或者你重写 HttpClientStack 类。

首先你应该替换你对 RequestQueue 的初始化

RequestQueue requestQueue = Volley.newRequestQueue(sContext);

到

    String userAgent = "volley/0";
    try {
        String packageName = getContext().getPackageName();
        PackageInfo info = getContext().getPackageManager().getPackageInfo(packageName, 0);
        userAgent = packageName + "/" + info.versionCode;
    } catch (PackageManager.NameNotFoundException e) {}
    HttpStack httpStack = new OwnHttpClientStack(AndroidHttpClient.newInstance(userAgent));
    RequestQueue requesQueue = Volley.newRequestQueue(sContext, httpStack);

并编写自己的 HttpClientStack 实现，在方法 createHttpRequest() 中更改“Method.POST:”的大小写。您还必须创建一个像“OwnHttpDelete”这样的对象作为 HttpEntityEnclosureRequestBase 的扩展，以使用方法 setEntityIfNonEmptyBody()。

public class OwnHttpClientStack extends com.android.volley.toolbox.HttpClientStack {
    private final static String HEADER_CONTENT_TYPE = "Content-Type";

    public OwnHttpClientStack(HttpClient client) {
        super(client);
    }

    @Override
    public HttpResponse performRequest(Request<?> request, Map<String, String> additionalHeaders)
            throws IOException, AuthFailureError {
        HttpUriRequest httpRequest = createHttpRequest(request, additionalHeaders);
        addHeaders(httpRequest, additionalHeaders);
        addHeaders(httpRequest, request.getHeaders());
        onPrepareRequest(httpRequest);
        HttpParams httpParams = httpRequest.getParams();
        int timeoutMs = request.getTimeoutMs();
        // TODO: Reevaluate this connection timeout based on more wide-scale
        // data collection and possibly different for wifi vs. 3G.
        HttpConnectionParams.setConnectionTimeout(httpParams, 5000);
        HttpConnectionParams.setSoTimeout(httpParams, timeoutMs);
        return mClient.execute(httpRequest);
    }

    private static void addHeaders(HttpUriRequest httpRequest, Map<String, String> headers) {
        for (String key : headers.keySet()) {
            httpRequest.setHeader(key, headers.get(key));
        }
    }

    static HttpUriRequest createHttpRequest(Request<?> request, Map<String, String> additionalHeaders) throws AuthFailureError {
        switch (request.getMethod()) {
            case Request.Method.DEPRECATED_GET_OR_POST: {
                byte[] postBody = request.getPostBody();
                if (postBody != null) {
                    HttpPost postRequest = new HttpPost(request.getUrl());
                    postRequest.addHeader(HEADER_CONTENT_TYPE, request.getPostBodyContentType());
                    HttpEntity entity;
                    entity = new ByteArrayEntity(postBody);
                    postRequest.setEntity(entity);
                    return postRequest;
                } else {
                    return new HttpGet(request.getUrl());
                }
            }
            case Request.Method.GET:
                return new HttpGet(request.getUrl());
            case Request.Method.DELETE:
                OwnHttpDelete deleteRequest =  new OwnHttpDelete(request.getUrl());
                deleteRequest.addHeader(HEADER_CONTENT_TYPE, request.getBodyContentType());
                setEntityIfNonEmptyBody(deleteRequest, request);
                return deleteRequest;
            case Request.Method.POST: {
                HttpPost postRequest = new HttpPost(request.getUrl());
                postRequest.addHeader(HEADER_CONTENT_TYPE, request.getBodyContentType());
                setEntityIfNonEmptyBody(postRequest, request);
                return postRequest;
            }
            case Request.Method.PUT: {
                HttpPut putRequest = new HttpPut(request.getUrl());
                putRequest.addHeader(HEADER_CONTENT_TYPE, request.getBodyContentType());
                setEntityIfNonEmptyBody(putRequest, request);
                return putRequest;
            }
            case Request.Method.HEAD:
                return new HttpHead(request.getUrl());
            case Request.Method.OPTIONS:
                return new HttpOptions(request.getUrl());
            case Request.Method.TRACE:
                return new HttpTrace(request.getUrl());
            case Request.Method.PATCH: {
                HttpPatch patchRequest = new HttpPatch(request.getUrl());
                patchRequest.addHeader(HEADER_CONTENT_TYPE, request.getBodyContentType());
                setEntityIfNonEmptyBody(patchRequest, request);
                return patchRequest;
            }
            default:
                throw new IllegalStateException("Unknown request method.");
        }
    }

    private static void setEntityIfNonEmptyBody(HttpEntityEnclosingRequestBase httpRequest,
                                                Request<?> request) throws AuthFailureError {
        byte[] body = request.getBody();
        if (body != null) {
            HttpEntity entity = new ByteArrayEntity(body);
            httpRequest.setEntity(entity);
        }
    }

    private static class OwnHttpDelete extends HttpPost {
        public static final String METHOD_NAME = "DELETE";

        public OwnHttpDelete() {
            super();
        }

        public OwnHttpDelete(URI uri) {
            super(uri);
        }

        public OwnHttpDelete(String uri) {
            super(uri);
        }

        public String getMethod() {
            return METHOD_NAME;
        }
    }
}

我希望我的代码对某人有所帮助。还应该可以向 HEAD 请求添加参数。

Answer 2

在阅读更多内容并深入研究 Volley 的代码后，我得出的结论是，在 Volley 中无法将参数附加到 DELETE 请求中 - 很可能是一种设计选择被普遍反对。

我想弄清楚怎么做，因为我想将 API 密钥附加到我发送到服务器的每种类型的请求中。

如果有人发现自己遇到了类似的问题，那么我最终要做的（我现在很确定这就是这里的方法）是在请求的标头部分发送 API 密钥。特别是在 Volley 中，这意味着重写 getHeaders() 方法并在那里添加您需要的参数。

这是我的代码：

@Override
public Map<String, String> getHeaders() throws AuthFailureError {
    Map<String, String> headers = super.getHeaders();

    if (headers == null
            || headers.equals(Collections.emptyMap())) {
        headers = new HashMap<String, String>();
    }

    headers.put("API_KEY", apiKey);

    return headers;
}