Question

我在解析文档时遇到错误。它显示一个空文档

错误：[请求处理失败；嵌套异常 java.lang.NullPointerException]的根本原因 java.lang.NullPointerException

String subBuildFile = "E:\Data Sync 4.4\WEB-INF\Temp_Project\Project_3";
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance(); 
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(new InputSource(subBuildFile));
Node s = doc.getElementsByTagName("userList").item(1);
for(int i =2; i < doc.getElementsByTagName("user").getLength(); i++) {
    doc.getElementsByTagName("userList").item(i)
        .removeChild(doc.getElementsByTagName("userList").item(i));
}

Answer 1

您的问题是您使用的InputSource错误。

您正在呼叫new InputSource(String)，而该构造函数说：

/**
 * Create a new input source with a system identifier.
 * ...
 * If the system identifier is a URL, it must be fully
 * resolved (it may not be a relative URL).
 *
 * @param systemId The system identifier (URI).
 */
 public InputSource (String systemId){...}

代替使用此构造函数：

/** Create a new input source with a character stream. */
public InputSource (Reader characterStream) { ... }

并像这样使用它：

Document doc = dBuilder.parse(new InputSource(new StringReader(subBuildFile)));

使用xml解析时显示null的文档

1 个答案: