如何获取 xml 标签内的值？

Question

我正在尝试获取 xml 文件的值。

<p1>
    <cts>Pq44</cts>
    <cts>qw44</cts>
</p1>

P1.JAVA

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class P1 {
    private List<Cts> cts;

     public P1() {
         cts = new ArrayList<cts>();
     }  
     public List<cts> getcts() {
        return cts;
     }
     public void setcts(List<cts> cts) {
        this.cts = cts;
     }
}

CTS.JAVA

public class CTS {

    private String ct;

    // Getter and setter for ct.

}

我的Main.java

try {            
    File file = new File("D:\\Bye.xml");
    JAXBContext jaxbContext = JAXBContext.newInstance(P1.class);

    Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
    P1 p = (P1) jaxbUnmarshaller.unmarshal(file);

    List<CTS> cts =  p.getCTS();
    // Size of list coming right `2`
    for (CTS c : cts) {
          System.out.println(CTS2.getCT());
    }
} catch (JAXBException e) {
    e.printStackTrace();
}

当我运行 main.java 时，它会打印：

null
null

Answer 1

我认为你的循环应该是这样的

for (CTS c : cts) {
    System.out.println(c.getCt());
}

Answer 2

您可以使用@XmlValue 并执行以下操作：

CTS

import javax.xml.bind.annotation.*;

@XmlAccessorType(XmlAccessType.FIELD)
public class CTS {

    @XmlValue
    private String ct;

    public String getCt() {
        return ct;
    }

    public void setCt(String ct) {
        this.ct = ct;
    }

}

P1

import java.util.*;
import javax.xml.bind.annotation.*;

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class P1 {

    private List<CTS> cts;

    public P1() {
        cts = new ArrayList<CTS>();
    }

    public List<CTS> getCts() {
        return cts;
    }

    public void setCts(List<CTS> cts) {
        this.cts = cts;
    }

}

p1.xml

<p1>
    <cts>Pq44</cts>
    <cts>qw44</cts>
</p1>

应用

import java.io.File;
import java.util.List;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;

/**
 * Hello world!
 *
 */
public class App 
{
    public static void main( String[] args ) throws JAXBException
    {
        System.out.println( "Hello World!" );
        String filePath = ".\\p1.xml";

        File file = new File(filePath);
        JAXBContext jaxbContext = JAXBContext.newInstance(P1.class);

        Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
        P1 p = (P1) jaxbUnmarshaller.unmarshal(file);

        List<CTS> cts =  p.getCts();
        // Size of list coming right `2`
        for (CTS c : cts) {
              System.out.println(c.getCt());
        }
    }
}

输出

Hello World!
Pq44
qw44

Answer 3

我已经做了一些工作。我正在发布我的代码，它将基于 XML 文件工作。

p1.xml

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<p1>
    <cts>Pq44</cts>
    <cts>qw44</cts>
</p1>

P1.java

import java.util.ArrayList;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name = "p1")
public class P1 {

    private ArrayList<String> cts;
    public ArrayList<String> getCts() {
        return cts;
    }
    public void setCts(ArrayList<String> cts) {
        this.cts = cts;
    }
}

TestApp.java

import java.io.File;
import java.util.List;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;

/**
 * Hello world!
 *
 */
public class App 
{
    public static void main( String[] args ) throws JAXBException
    {
        System.out.println( "Hello World!" );
        String filePath = ".\\p1.xml";

        File file = new File(filePath);
        JAXBContext jaxbContext = JAXBContext.newInstance(P1.class);

        Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
        P1 p = (P1) jaxbUnmarshaller.unmarshal(file);

        List<String> cts =  p.getCts();
        // Size of list coming right `2`
        for (String c : cts) {
              System.out.println(c);
        }
    }
}

试试这个方法会很好用的。

输出

Hello World!
Pq44
qw44