Question

如何将变量作为指针传递给函数？我有以下代码我想重构

    public static HttpResponse getJSONEntityFromURL(Context context, String url) throws ClientProtocolException, IOException {
        HttpClient httpclient = new DefaultHttpClient();
        HttpGet httpget = new HttpGet(url);
        httpget.addHeader("Accept", "application/json");
        httpget.addHeader("Content-Type", "application/json; charset=UTF-8");
        HttpResponse response;

        response = httpclient.execute(httpget);
        return response;
    }

这样的事情

    public static HttpResponse getJSONEntityFromURL(Context context, String url) throws ClientProtocolException, IOException {
        HttpClient httpclient = new DefaultHttpClient();
        HttpGet httpget = new HttpGet(url);
            setHeaders(httpget);
        HttpResponse response;

        response = httpclient.execute(httpget);
        return response;
    }

private static void setHeaders(HttpRequestBase httpget) {
    httpget.addHeader("Accept", "application/json");
    httpget.addHeader("Content-Type", "application/json; charset=UTF-8");
}

我假设我需要将httpget参数作为指针传递？

Answer 1

我假设我需要将httpget参数作为指针传递？

不，因为Java没有指针。

你在那里的代码似乎很好 - 你将HttpGet对象传递给setHeaders()并在其上调用方法。如果您对当前语法有特定问题，请解释。

Answer 2

我会用那个

private static void setHeaders(final HttpRequestBase httpget) {
  httpget.addHeader("Accept", "application/json");
  httpget.addHeader("Content-Type", "application/json; charset=UTF-8");
}

确定它不是指针，但在这种情况下，引用httpget会在不返回HttpRequestBase的情况下进行更改。

Answer 3

Java只允许传递引用，因为Java没有实现指针算法

所有基本类型都通过复制传递，所有对象类型都由ref传递。（通过复制，但是内存地址的副本而不是复制整个对象。）

你认为的方式是正确的：

private static void setHeaders(HttpRequestBase AGet) {
    AGet.addHeader("Accept", "application/json");
    AGet.addHeader("Content-Type", "application/json; charset=UTF-8");
}

除非您需要在其他地方使用此方法，否则我建议使用第一个代码。

http://docs.oracle.com/javase/tutorial/java/javaOO/arguments.html＆lt; - documentation

Answer 4

您可以使用HttpMessage界面，如下所示： -

http://developer.android.com/reference/org/apache/http/HttpMessage.html

这将允许您接受此接口的实现，即HttpGet的实例

即： -

private static void setHeaders(HttpMessage httpMessage) 
{
    httpMessage.addHeader("Accept", "application/json");
    httpMessage.addHeader("Content-Type", "application/json; charset=UTF-8");
}

Android，如何将变量作为指针传递给函数？

4 个答案: