SAXParser - 从 XML 元素解码值后，仅获得字符长度 126

Posted 2023-02-24

【中文标题】SAXParser - 从 XML 元素解码值后，仅获得字符长度 126

【英文标题】：SAXParser - After decoding the values from the XML element obtains only character length 126

【发布时间】：2013-05-18 09:45:02

【问题描述】：

我正在尝试使用 SAXParser 从下面显示的 xml 中的元素“UserDetails”中获取编码字符。我只能获得长度为 126 的前 2 行编码字符。我无法获得所有编码字符。检索这些字符的任何想法。

**User.xml**

<UserStatus>FALSE</UserStatus>
<UserDetails>
**AAAAAAAA//8BAAAAAAAAAAEAAQAAAP///f///wAAAQAAAAAAAgABAAIAAQAAAAAA//8CAAAAAAABAP////8A
AAAA//8AAP////8AAAAA/////wAA//////3//f/9//7//v/9/wAA/f/8//z//P/8//3//v/+//7//P/9//3/**
/P/7//r/+//8//v/+//6//r/+//5//n//P/6//r//P/6//n/+P/6//r/+v/6//r/+v/7//z//P/5//r/+v/7
//r/+f/5//r/+v/5//r/+f/5//r/+//6//n/9//3//n/+f/5//j/9//5//n/+P/5//n/+f/6//f/+P/4//f/
+P/5//j/+f/6//f/9v/2//f/9//3//n/+v/4//n/+f/3//b/9//4//n/9//4//b/9//0//f/9v/3//b/9//2
//T/9f/5//T/9f/2//X/9P/2//b/9v/0//T/8//2//T/9P/0//X/9v/1//f/9P/0//L/8v/y//L/9v/3//b/
9v/2//f/9v/1//X/9f/1//T/9v/3//X/9f/1//b/9v/2//b/9//3//n/9//1//T/8//1//b/9v/3//n/9//1
//T/9P/0//X/9v/0//b/9v/3//b/9v/1//P/9P/1//f/9//2//n/9//3//b/9//3//f/9//4//f/+f/3//b/
9v/0//X/9v/5//n/9//6//f/9//4//f/9//4//j/9//5//n/+f/2//X/9//0//T/9f/2//j/9v/4//b/9f/1
//T/9f/1//f/9v/3//X/9v/2//b/9f/1//T/9f/5//j/+P/4//n/+P/3//b/+P/4//f/9//2//j/+f/2//b/
</UserDetails>
<UserStatus>TRUE</UserStatus>
<UserDetails>
**AAAAAAAA//8BAAAAAAAAAAEAAQAAAP///f///wAAAQAAAAAAAgABAAIAAQAAAAAA//8CAAAAAAABAP////8A
AAAA//8AAP////8AAAAA/////wAA//////3//f/9//7//v/9/wAA/f/8//z//P/8//3//v/+//7//P/9//3/**
/P/7//r/+//8//v/+//6//r/+//5//n//P/6//r//P/6//n/+P/6//r/+v/6//r/+v/7//z//P/5//r/+v/7
//r/+f/5//r/+v/5//r/+f/5//r/+//6//n/9//3//n/+f/5//j/9//5//n/+P/5//n/+f/6//f/+P/4//f/
+P/5//j/+f/6//f/9v/2//f/9//3//n/+v/4//n/+f/3//b/9//4//n/9//4//b/9//0//f/9v/3//b/9//2
//T/9f/5//T/9f/2//X/9P/2//b/9v/0//T/8//2//T/9P/0//X/9v/1//f/9P/0//L/8v/y//L/9v/3//b/
9v/2//f/9v/1//X/9f/1//T/9v/3//X/9f/1//b/9v/2//b/9//3//n/9//1//T/8//1//b/9v/3//n/9//1
//T/9P/0//X/9v/0//b/9v/3//b/9v/1//P/9P/1//f/9//2//n/9//3//b/9//3//f/9//4//f/+f/3//b/
9v/0//X/9v/5//n/9//6//f/9//4//f/9//4//j/9//5//n/+f/2//X/9//0//T/9f/2//j/9v/4//b/9f/1
//T/9f/1//f/9v/3//X/9v/2//b/9f/1//T/9f/5//j/+P/4//n/+P/3//b/+P/4//f/9//2//j/+f/2//b/
</UserDetails>



**UserDetails.java**

import java.io.File;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class UserDetails 

    public static void main(String args[])

    File file = new File("C:/user_records/User.xml");

    final StringBuffer curCharValue = new StringBuffer(1024);

    try 
        SAXParserFactory factory = SAXParserFactory.newInstance();
        SAXParser saxParser = factory.newSAXParser();

        DefaultHandler handler = new DefaultHandler() 
            String sd = "";
            String createdStr = "";

            boolean stat= false;

            public void startElement(String uri, String localName,
                    String qName, Attributes attributes)
                    throws SAXException 
                curCharValue.setLength(0);
                System.out.println("Start Element :" + qName);

                if (qName.equalsIgnoreCase("UserDetails")) 
                    stat= true;
                

            

            public void endElement(String uri, String localName,
                    String qName) throws SAXException 

                System.out.println("End Element : " + qName);

            

            public void characters(char ch[], int start, int length)
                    throws SAXException 

                if (stat) 
                    System.out.println("User Details are : "
                            + new String(ch, start, length));

                    curCharValue.append(ch, start, length);

                    byte[] decoded = Base64.decodeBase64(new String(
                            curCharValue));

                    System.out.println(decoded.length
                            + " is decoded length");
                    for (int i = 0; i < decoded.length; i++) 

                        createdStr = decoded[i] + "";
                        if (createdStr.equals("-")
                                || i == (decoded.length - 1)) 
                            sd += decoded[i];
                         else 
                            sd += decoded[i] + ",";
                        
                    

                    System.out.println("the actual user details are : "
                            + sd);
                    stat= false;
                

            

        ;

        saxParser.parse(file, handler);

     catch (Exception e) 
        e.printStackTrace();
    

【参考方案1】：

ContentHandler.characters API 说 Parser 将调用此方法来报告每个字符数据块。 SAX 解析器可以在单个块中返回所有连续的字符数据，也可以将其拆分为多个块

你应该在一个字符串中收集这些块

【参考方案2】：

characters(char ch[], int start, int length) 将由节点 UserDetails 的解析器调用多次，每次调用时您都必须添加 ch[] 。您可以将元素开始名称保留为一个变量并使用 startElement() 的 qName 设置它，然后检查变量以确保 characters() 被多次调用但仍然是相同的起始元素。