问题是在com.android.volley.toolBox.HttpClientStack.java中实现createHttpRequest方法,只有在请求方法为POST,PUT或PATCH时才会添加该主体.

/**
 * 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.");
    }
}

所以你必须使用自己的HttpStack.java实现,或者你重写HttpClientStack类.

首先你应该替换你的初始化RequestQueue

RequestQueue requestQueue = Volley.newRequestQueue(sContext);

至

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);

并编写您自己的HttpClientStack实现,您可以在createHttpRequest()方法中更改“Method.POST：”的大小写.您还必须创建一个像“OwnHttpDelete”这样的对象,作为HttpEntityEnclosingRequestBase的扩展,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,String> additionalHeaders)
            throws IOException,AuthFailureError {
        HttpUriRequest httpRequest = createHttpRequest(request,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,String> headers) {
        for (String key : headers.keySet()) {
            httpRequest.setHeader(key,headers.get(key));
        }
    }

    static HttpUriRequest createHttpRequest(Request<?> request,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;
        }
    }
}

我希望我的代码能帮助某人.还可以向HEAD请求中添加参数.