我这里有两节课。第一个是将数据写入XML文件，第二个是使用JFrame，并使用按钮上的动作处理程序从三个文本字段中收集数据。
我的两个问题：
1）GUI是空白的 - 自从我玩JFrame以来已经有一段时间了，所以请耐心等待。
2）我需要从文本框中提取3个字符串，然后将它们插入到insertNewEntry（）函数中。该属性只是一个我将递增的整数，元素和文档将分别为＆＃34; rootElement＆＃34;和＆＃34; doc＆＃34 ;.
非常感谢您的帮助！
import java.io.File;
import java.util.*;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.swing.*;
import java.awt.*;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
@SuppressWarnings("unused")
public class createXML extends JFrame {
private static final long serialVersionUID = 1L;
public static void main(String [] args) throws ParserConfigurationException, TransformerException{
String address = "/home/leo/workspace/Test/Files/src/xmlOutput";
Scanner s = new Scanner(System.in);
int ID = 0;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.newDocument();
Element rootElement = doc.createElement("Company");
doc.appendChild(rootElement);
GUI gui = new GUI();
gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
gui.setSize(500, 300);
gui.setVisible(true);
// insertNewEntry(rootElement, doc, ID, firstName, lastName, salary);
TransformerFactory tf = TransformerFactory.newInstance();
Transformer t = tf.newTransformer();
DOMSource source = new DOMSource(doc);
StreamResult sr = new StreamResult(new File(address));
t.transform(source, sr);
System.out.println("File created.");
}
private static void insertNewEntry(Element rootElement, Document doc, String attr, String fName, String lName, String sal){
Element employee = doc.createElement("Employee");
employee.setAttribute("ID", attr);
rootElement.appendChild(employee);
Element firstName = doc.createElement("First_Name");
firstName.setTextContent(fName);
employee.appendChild(firstName);
Element lastName = doc.createElement("Last_Name");
lastName.setTextContent(lName);
employee.appendChild(lastName);
Element salary = doc.createElement("Salary");
salary.setTextContent(sal);
employee.appendChild(salary);
}
}
下一课......
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
@SuppressWarnings("unused")
public class GUI extends JFrame {
private static final long serialVersionUID = 1L;
private JLabel item;
private JTextField firstName;
private JTextField lastName;
private JTextField salary;
private JButton button1;
GUI(){
super("XML Writer");
JPanel panel = new JPanel();
panel.setLayout(new GridLayout(0,2));
JLabel fn = new JLabel("First Name");
firstName = new JTextField();
panel.add(fn);
panel.add(firstName);
JLabel ln = new JLabel("Last Name");
lastName = new JTextField();
panel.add(ln);
panel.add(lastName);
JLabel s = new JLabel("Salary");
salary = new JTextField();
panel.add(s);
panel.add(salary);
button1 = new JButton("Click Me!");
button1.setSize(20, 10);
panel.add(button1);
Handler handler = new Handler();
button1.addActionListener(handler);
}
private class Handler implements ActionListener{
public void actionPerformed(ActionEvent event){
String fn = ""; String ln = ""; String sal = "";
fn = firstName.getText();
ln = lastName.getText();
sal = salary.getText();
JOptionPane.showMessageDialog(null, "Information stored in XML file");
}
}
}
答案 0 :(得分：2)
让我们从明显的问题开始......
您创建了一个JPanel，添加了您的组件，但从未将panel添加到任何内容....
GUI() {
super("XML Writer");
JPanel panel = new JPanel();
panel.setLayout(new GridLayout(0, 2));
JLabel fn = new JLabel("First Name");
firstName = new JTextField();
panel.add(fn);
panel.add(firstName);
JLabel ln = new JLabel("Last Name");
lastName = new JTextField();
panel.add(ln);
panel.add(lastName);
JLabel s = new JLabel("Salary");
salary = new JTextField();
panel.add(s);
panel.add(salary);
button1 = new JButton("Click Me!");
button1.setSize(20, 10);
panel.add(button1);
Handler handler = new Handler();
button1.addActionListener(handler);
//...???
}
尝试将panel添加到GUI ...
add(panel);
}
此外，您的CreateXML课程不需要从JFrame延伸，它甚至不使用任何功能......
你的第二个问题是意见问题......
基本解决方案是调用static createXML.insertNewEntry(...)方法，但您的GUI缺少一些所需的信息才能使其正常工作......
就个人而言，我会创建一个“模型”interface，其中包含Document和简化的insert方法，该方法仅从GUI中获取必需的字段...
更新了模型示例
基本模型结构......
public interface EmployeeModel {
public void insert(String fName, String lName, String sal);
}
public interface XMLEmployeeModel extends EmployeeModel {
public void save(File file) throws IOException;
}
public abstract class AbstractXMLEmployeeModel implements XMLEmployeeModel {
private Document doc;
public AbstractXMLEmployeeModel(Document doc) {
this.doc = doc;
}
public Document getDoc() {
return doc;
}
@Override
public void save(File file) throws IOException {
try {
TransformerFactory tf = TransformerFactory.newInstance();
Transformer t = tf.newTransformer();
DOMSource source = new DOMSource(doc);
StreamResult sr = new StreamResult(file);
t.transform(source, sr);
} catch (TransformerFactoryConfigurationError | TransformerException exp) {
exp.printStackTrace();
throw new IOException("Failed to save Employee model", exp);
}
}
}
public class DefaultXMLEmployeeModel extends AbstractXMLEmployeeModel {
private int count = 0;
public DefaultXMLEmployeeModel(Document doc) {
super(doc);
}
@Override
public void insert(String fName, String lName, String sal) {
Document doc = getDoc();
Element root = doc.getDocumentElement();
Element employee = doc.createElement("Employee");
employee.setAttribute("ID", Integer.toString(count++));
root.appendChild(employee);
Element firstName = doc.createElement("First_Name");
firstName.setTextContent(fName);
employee.appendChild(firstName);
Element lastName = doc.createElement("Last_Name");
lastName.setTextContent(lName);
employee.appendChild(lastName);
Element salary = doc.createElement("Salary");
salary.setTextContent(sal);
employee.appendChild(salary);
}
}
GUI利用它的例子......
public static class GUI extends JFrame {
//...
private XMLEmployeeModel model;
GUI(XMLEmployeeModel model) {
super("XML Writer");
this.model = model;
//...
}
private class Handler implements ActionListener {
public void actionPerformed(ActionEvent event) {
String fn = "";
String ln = "";
String sal = "";
fn = firstName.getText();
ln = lastName.getText();
sal = salary.getText();
model.insert(fn, ln, sal, sal);
JOptionPane.showMessageDialog(null, "Information stored in XML file");
}
}
}