Java系统变量设置方式

近期碰到一个编码的问题，发现整个平台都是用的GB2312，因此导致webservice调用时有些字不能正常接受。

反编译中间件的源码如下：

public static final String node2String(Node node, boolean isPreserveSpace)
  {
    if (node == null)
      return null;
    if (node.getNodeType() == 9) {
      node = ((Document)node).getDocumentElement();
    }
    OutputFormat format = new OutputFormat(node.getOwnerDocument());

    String strEncoding = System.getProperty("xml.encoding");
    if (strEncoding != null) format.setEncoding(strEncoding); else {
     format.setEncoding("GB2312");
    }
    format.setIndenting(false);

    format.setPreserveSpace(isPreserveSpace);
    StringWriter stringOut = new StringWriter();
    XMLSerializer serial = new XMLSerializer(stringOut, format);
    try {
      serial.asDOMSerializer();
      serial.serialize((Element)node);
    } catch (IOException ex) {
      throw new EOSFailure(ex);
    }
    return stringOut.toString();
  }