如何用XMLReader读相同节点下的值？

Question

XML文件:

<Human>
   <person>
        Jack
   </person>
   <person>
        Tom
   </person>
   <person>
        Jerry
   </person>
</Human>

**代码：**

$reader = new XMLReader();
  $reader->open("example.xml");
    while ($reader->read()) {
      if($reader->nodeType==XMLREADER::ELEMENT) {
             if ($reader->localName == "Human") {
                    while ($reader->read()) {
                       if ($reader->nodeType == XMLREADER::ELEMENT) {
                                if ($reader->localName == "person") {
                                     $reader->read();
                                     echo $reader->value;

                                }
                                ...

while语句跳出需要执行break;但这里不知道从哪儿跳出，可以保证全部读出Tom,Jack,Jerry?