JButton btnStart = new JButton("Start");
btnStart.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
try{
String filename = fileName.getText();
FileReader fr = new FileReader(filename);
BufferedReader br = new BufferedReader(fr);
Scanner scan = new Scanner(br);
filename = br.readLine();
if (filename != null){
String text = txtKeyword.getText();
String line;
boolean hasError = true;
while ((line = br.readLine()) != null) {
if(line.contains(text)){
String newline = "\n";
jTextArea1.append(line + newline);
hasError = false;
}
}
if (hasError) {
JOptionPane.showMessageDialog(null, "Text Not Found");
br.close();
fr.close();
}
}}catch(IOException e){
JOptionPane.showMessageDialog(null, "File Not Found");
} }
});
所以，在这个函数中，我想通过输入读取所提到的目录/文件夹中的一些文本文件。用户使用JFILECHOOSER方法选择目录/文件夹，输出将列在文本框[目录]中。假设fileName是用户输入文件名的文本字段，用户输入文件名后，单击开始按钮。启动按钮起作用，它将查看给定的目录/文件夹[文本框]并搜索文本文件并使用system.out.printIn输出文本文件的名称。我没有尝试过目录/文件夹路径的代码，因为我不确定如何为它编码。对此问题的任何帮助或指导？我只创建了一个类，我是JAVA GUI的新手
完整代码如下：
package com.directory.file;
import java.awt.BorderLayout;
import java.awt.Event;
import java.awt.EventQueue;
import java.awt.TextArea;
import java.awt.TextComponent;
import java.awt.Event.*;
import java.io.FileReader;
import java.io.BufferedReader;
import java.util.Scanner;
import javax.lang.model.element.VariableElement;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
import javax.swing.JLabel;
import javax.swing.JTextArea;
import javax.swing.JButton;
import javax.swing.JSpinner;
import javax.swing.SpinnerModel;
import javax.swing.SpinnerNumberModel;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Scanner;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.Component;
import java.sql.*;
import java.util.Scanner;
import javax.swing.JFileChooser;
import javax.swing.JSplitPane;
import javax.swing.JLayeredPane;
import javax.swing.JDesktopPane;
import javax.swing.JComboBox;
import javax.swing.JSeparator;
import javax.swing.JTextField;
import javax.swing.JTextPane;
import javax.swing.SpinnerDateModel;
import javax.swing.border.CompoundBorder;
import javax.swing.border.LineBorder;
import javax.swing.text.JTextComponent;
import java.awt.Color;
import javax.swing.SwingConstants;
import java.awt.ComponentOrientation;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Calendar;
import com.toedter.calendar.JDateChooser;
import javax.swing.JSpinner;
import org.eclipse.wb.swing.FocusTraversalOnArray;
public class Directory extends JFrame {
private JPanel contentPane;
private JTextField txtKeyword;
private JTextField fileName;
private JTextArea jTextArea1;
private JDateChooser dateChooser;
private JSpinner spinner_1;
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Directory frame = new Directory();
frame.setVisible(true);
frame.setSize(450,630);
frame.fileName.requestFocus();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public Directory() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 436, 631);
contentPane = new JPanel();
contentPane.setAlignmentX(Component.LEFT_ALIGNMENT);
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);
JLabel lblDirectory = new JLabel("Directory:");
lblDirectory.setBounds(20, 29, 55, 24);
contentPane.add(lblDirectory);
JLabel lblDate = new JLabel("Date:");
lblDate.setBounds(37, 141, 55, 24);
contentPane.add(lblDate);
txtKeyword = new JTextField();
txtKeyword.setHorizontalAlignment(SwingConstants.CENTER);
txtKeyword.setToolTipText("");
txtKeyword.setColumns(10);
txtKeyword.setBounds(85, 193, 229, 20);
contentPane.add(txtKeyword);
final JDateChooser dateChooser = new JDateChooser();
dateChooser.setDateFormatString("YYYMMd");
dateChooser.setBounds(85, 141, 229, 20);
contentPane.add(dateChooser);
JLabel lblKeyword = new JLabel("Keyword:");
lblKeyword.setBounds(20, 191, 55, 24);
contentPane.add(lblKeyword);
JSeparator separator = new JSeparator();
separator.setBounds(148, 204, -113, 34);
contentPane.add(separator);
JButton btnExport = new JButton("Export");
btnExport.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
}
});
btnExport.setBounds(324, 556, 89, 23);
contentPane.add(btnExport);
final JLabel Directory = new JLabel("");
Directory.setBorder(new LineBorder(new Color(0, 0, 0)));
Directory.setBounds(85, 30, 290, 22);
contentPane.add(Directory);
int min = 0;
int max = 23;
int step = 1;
int initValue = 0;
SpinnerModel sm = new SpinnerNumberModel(initValue, min, max, step);
final JSpinner spinner_1 = new JSpinner(new SpinnerNumberModel(0, 0, 23-1, 1));
spinner_1.setBounds(324, 143, 89, 20);
contentPane.add(spinner_1);
JButton btnNewButton = new JButton("...");
btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JFileChooser chooser = new JFileChooser();
chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
chooser.showOpenDialog(null);
File f = chooser.getSelectedFile();
String filename =f.getAbsolutePath();
Directory.setText(filename);
});
btnNewButton.setBounds(377, 30, 36, 23);
contentPane.add(btnNewButton);
final JTextArea jTextArea1 = new JTextArea();
jTextArea1.setRows(15);
jTextArea1.setColumns(15);
jTextArea1.setBounds(42, 249, 351, 294);
jTextArea1.setLineWrap(true);
jTextArea1.setWrapStyleWord(true);
contentPane.add(jTextArea1);
jTextArea1.setEditable(false);
JButton btnStart = new JButton("Start");
btnStart.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
try{
String filename = fileName.getText();
FileReader fr = new FileReader(filename);
BufferedReader br = new BufferedReader(fr);
Scanner scan = new Scanner(br);
filename = br.readLine();
if (filename != null){
String text = txtKeyword.getText();
String line;
boolean hasError = true;
while ((line = br.readLine()) != null) {
if(line.contains(text)){
String newline = "\n";
jTextArea1.append(line + newline);
hasError = false;
}
}
if (hasError) {
JOptionPane.showMessageDialog(null, "Text Not Found");
br.close();
fr.close();
}
}}catch(IOException e){
JOptionPane.showMessageDialog(null, "File Not Found");
} }
});
btnStart.setBounds(324, 215, 89, 23);
contentPane.add(btnStart);
JLabel lblFileName_1 = new JLabel("File Name:");
lblFileName_1.setBounds(20, 79, 75, 24);
contentPane.add(lblFileName_1);
fileName = new JTextField();
fileName.setToolTipText("");
fileName.setHorizontalAlignment(SwingConstants.CENTER);
fileName.setColumns(10);
fileName.setBounds(85, 81, 290, 20);
contentPane.add(fileName);
contentPane.setFocusTraversalPolicy(new FocusTraversalOnArray(new Component[]{fileName, lblDirectory, lblDate, txtKeyword, btnStart, lblKeyword, separator, btnExport, Directory, dateChooser, dateChooser.getCalendarButton(), spinner_1, btnNewButton, jTextArea1, lblFileName_1}));
}
}
答案 0 :(得分：1)
尝试打开文件时，您只使用fileName值...
FileReader fr = new FileReader(filename);
文件是目录和名称的连接，例如......
FileReader fr = new FileReader(new File(Directory.getText(), filename));
您正在对文件进行某种先发制人的阅读，这不是必需的......
if (filename != null){
String text = txtKeyword.getText();
String line;
boolean hasError = true;
while ((line = br.readLine()) != null) {
您应该开始阅读该文件，否则您已经丢失了第一行文字
如果遇到某种异常，你不会关闭这些流......
try {
FileReader fr = new FileReader(new File(Directory.getText(), filename));
BufferedReader br = new BufferedReader(fr);
//...
} catch (IOException e) {
JOptionPane.showMessageDialog(null, "File Not Found");
}
如果出于某种原因，在打开或读取流时发生异常，则永远不会关闭它们...至少在JVM关闭之前不会出现
相反，如果您使用Java 7+或try-with-resources块来确保流已关闭，则应使用finally，例如......
BufferedReader br = null;
try {
String filename = fileName.getText();
br = new BufferedReader(new FileReader(new File(Directory.getText(), filename)));
//...
} catch (IOException e) {
JOptionPane.showMessageDialog(null, "File Not Found");
} finally {
try {
br.close();
} catch (Exception e) {
}
}
如果您至少转储了实际异常的堆栈跟踪或者记录了一些如何...它将对您有所帮助...
} catch (IOException e) {
e.printStackTrace();
JOptionPane.showMessageDialog(null, "File Not Found");
} finally {
null布局。像素完美布局是现代UI设计中的一种幻觉，您无法控制字体，DPI，渲染管道或其他因素，这些因素将改变组件在屏幕上呈现的方式。
Swing旨在与布局管理员合作以克服这些问题。如果你坚持忽略这些功能并违背API设计，那就要做好准备应对很多令人头疼的事情，永远不要过时努力......