Question

我使用java下面的代码创建了Web服务调用。现在我需要进行删除和执行操作。

URL url = new URL("http://example.com/questions");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod( "POST" );
conn.setRequestProperty("Content-Type", "application/json");

OutputStream os = conn.getOutputStream();
os.write(jsonBody.getBytes());
os.flush();

当我添加以下代码来执行DELETE操作时，它会出错：

java.net.ProtocolException：HTTP方法DELETE不支持输出。

conn.setRequestMethod( "DELETE" );

那么如何执行删除和发出请求？

Answer 1

PUT示例使用HttpURLConnection：

URL url = null;
try {
   url = new URL("http://localhost:8080/putservice");
} catch (MalformedURLException exception) {
    exception.printStackTrace();
}
HttpURLConnection httpURLConnection = null;
DataOutputStream dataOutputStream = null;
try {
    httpURLConnection = (HttpURLConnection) url.openConnection();
    httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
    httpURLConnection.setRequestMethod("PUT");
    httpURLConnection.setDoInput(true);
    httpURLConnection.setDoOutput(true);
    dataOutputStream = new DataOutputStream(httpURLConnection.getOutputStream());
    dataOutputStream.write("hello");
} catch (IOException exception) {
    exception.printStackTrace();
}  finally {
    if (dataOutputStream != null) {
        try {
            dataOutputStream.flush();
            dataOutputStream.close();
        } catch (IOException exception) {
            exception.printStackTrace();
        }
    }
    if (httpsURLConnection != null) {
        httpsURLConnection.disconnect();
    }
}

DELETE示例使用HttpURLConnection：

URL url = null;
try {
    url = new URL("http://localhost:8080/deleteservice");
} catch (MalformedURLException exception) {
    exception.printStackTrace();
}
HttpURLConnection httpURLConnection = null;
try {
    httpURLConnection = (HttpURLConnection) url.openConnection();
    httpURLConnection.setRequestProperty("Content-Type",
                "application/x-www-form-urlencoded");
    httpURLConnection.setRequestMethod("DELETE");
    System.out.println(httpURLConnection.getResponseCode());
} catch (IOException exception) {
    exception.printStackTrace();
} finally {         
    if (httpURLConnection != null) {
        httpURLConnection.disconnect();
    }
}

Answer 2

我建议您使用restlet客户端进行Web服务请求。请参考下面的示例代码，它可能对您有所帮助

 Client client = new Client(new Context(), Protocol.HTTP);
   clientResource = new ClientResource(url);
        ResponseRepresentation responseRep = null;
         try {
            clientResource.setNext(client);           
            clientResource.delete();

       } catch (Exception e) {
           e.printStackTrace();

       }

Answer 3

FOR PUT

URL url = new URL("http://www.example.com/resource");
HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
httpCon.setDoOutput(true);
httpCon.setRequestMethod("PUT");
OutputStreamWriter out = new OutputStreamWriter(
    httpCon.getOutputStream());
out.write("Resource content");
out.close();
httpCon.getInputStream();

FOR DELETE

URL url = new URL("http://www.example.com/resource");
HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();
httpCon.setDoOutput(true);
httpCon.setRequestProperty(
    "Content-Type", "application/x-www-form-urlencoded" );
httpCon.setRequestMethod("DELETE");
httpCon.connect();

实际上是从这里的链接获得的： Send PUT, DELETE HTTP request in HttpURLConnection

在HttpURLConnection中发送PUT，DELETE HTTP请求

3 个答案: