请写出java通过拼接xml请求webservice服务的代码

下面是一个通过拼接XML请求Web服务的Java代码示例：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class WebServiceClient {

    public static void main(String[] args) {
        try {
            URL url = new URL("http://example.com/MyWebService");
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Content-Type", "text/xml");

            String requestXML = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
                    "<soapenv:Envelope xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:web=\"http://example.com/webservice\">\n" +
                    "   <soapenv:Header/>\n" +
                    "   <soapenv:Body>\n" +
                    "      <web:MyOperation>\n" +
                    "         <web:Param1>Value1</web:Param1>\n" +
                    "         <web:Param2>Value2</web:Param2>\n" +
                    "      </web:MyOperation>\n" +
                    "   </soapenv:Body>\n" +
                    "</soapenv:Envelope>";

            connection.setDoOutput(true);
            connection.getOutputStream().write(requestXML.getBytes());

            BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }

            reader.close();
            connection.disconnect();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

在这个例子中，我们首先创建一个URL对象并打开一个HttpURLConnection。设置HTTP请求方法为POST并设置Content-Type为text/xml。 然后，我们创建一个包含所需参数的XML字符串，并将其发送到Web服务。 最后，我们读取响应并在控制台上打印它。