java读取XML

Posted 2020-11-11 需要重生的鹰

方法不在多，能用就好。

我采用的是dom4j

    <dependency>
     <groupId>dom4j</groupId>
     <artifactId>dom4j</artifactId>
     <version>1.6.1</version>
    </dependency>

读取的文件内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<users>
    <module id="1">
        <user index="1">
            <name>tom</name>
            <password>12345</password>
            <date>20150526</date>
        </user>
        <user index="2">
            <name>jack</name>
            <password>5%</password>
            <date>20150526</date>
        </user>
        <user index="3">
            <name>john</name>
            <password>5%</password>
            <date>20150526</date>
        </user>
    </module>
</users>

读取思路是：

1. 创建一个SAXReader实例;

2. 创建一个文件读取BufferedReader实例;

3. 创建一个Document实例读取BufferedReader;

4. 获取xml文件的根节点;

5. 获取根节点的子节点;

6. 遍历子节点，获取节点名用getName(),获取节点的值用getText(),获取属性值用attributeValue(String)

获取根节点的代码如下：

    public static List<Element> readXml(String FilePath){
        BufferedReader in = null;
        List<Element> elementlist = null;
        Document doc = null;
        
        SAXReader reader = new SAXReader();
        try {
            in = new BufferedReader(new FileReader(FilePath));
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try {
            doc = reader.read(in);
        } catch (DocumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
        Element root = doc.getRootElement();
        elementlist = root.elements();
        
        return elementlist;
        
    }

遍历子节点, 读取用户名和密码的代码如下：

    @SuppressWarnings("unchecked")
    public List<HashMap<String, String>> readUserDotXML(String path, String module_id){
        List<HashMap<String, String>> users = new ArrayList<HashMap<String, String>>();
        String rootPath = path;
        List<Element> list = ReadXML.readXml(rootPath);
        if (list != null) {
            for (Element ele : list) {
                String index = ele.attributeValue("id");
                if(module_id.equals(index)){
                    List<Element> userList = ele.elements();
                    if(userList != null && userList.size()>0){
                        for (Element user : userList) {
                            HashMap<String,String> hashMap = new HashMap<String, String>();
                            Element name = user.element("name");
                            Element password = user.element("password");
                            String nameValue = name.getText();
                            String passwordValue = password.getText();
                            hashMap.put("name", nameValue);
                            hashMap.put("password", passwordValue);
                            users.add(hashMap);
                        }
                    }
                    
                    break;
                }
            }
        }
        
        return users;
        
    }

main函数调用方法如下:

List<HashMap<String, String>> resultlist= readxml.readUserDotXML("e:/testXML.xml","1");

for (HashMap<String, String> hashMap : resultlist) {
    System.out.println(hashMap.get("name"));
    System.out.println(hashMap.get("password"));
}

使用java总感觉没python那么干脆，这里多几步，那里多几步的。下次对python也总结一下xml读取