java代码问题求助,下面的代码是想要点击按钮后从本地选取文件,并将文件内容显示在文本区。大家帮忙看看
我编译时报了
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p185_6.java:50: 警告: catch 子句无法访问
catch(IOException e2){System.out.println("文件读写错");}
改正后文件可以在页面内显示,就是位置有点问题。
可以把add(jta,BorderLayout.SOUTH);改成add(jta,BorderLayout.CENTER);
如果想使用滚动条,可以把JTextArea放在JScrollPane里,然后再放在JFrame中。
add(jta,BorderLayout.SOUTH);改成add(new JScrollPane(jta),BorderLayout.CENTER);
如何在Java Swing中显示系统样式的文件选择框?类似JavaFX的FileChooser外观
完整的java代码如下:
import javax.swing.*;
import java.awt.event.*;
public class FileChooserDemo extends JFrame implements ActionListener {
// 创建一个按钮,用于打开文件选择框
private JButton openButton;
// 创建一个文件选择框对象
private JFileChooser fileChooser;
public FileChooserDemo() {
// 设置窗口标题和大小
super("文件选择框示例");
setSize(300, 200);
// 设置窗口布局为流式布局
setLayout(new FlowLayout());
// 初始化按钮,并添加动作监听器
openButton = new JButton("打开文件");
openButton.addActionListener(this);
// 初始化文件选择框,并设置为系统样式[^1^][2]
fileChooser = new JFileChooser();
fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
SwingUtilities.updateComponentTreeUI(fileChooser);
} catch (Exception e) {
e.printStackTrace();
}
// 将按钮添加到窗口中
add(openButton);
// 设置窗口可见和关闭操作
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
@Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == openButton) {
// 当点击打开文件按钮时,弹出文件选择框[^2^][1]
int result = fileChooser.showOpenDialog(this);
if (result == JFileChooser.APPROVE_OPTION) {
// 当用户选择了一个文件时,获取并显示文件路径
String filePath = fileChooser.getSelectedFile().getPath();
JOptionPane.showMessageDialog(this, "你选择了:" + filePath);
}
}
}
public static void main(String[] args) {
new FileChooserDemo();
}
}
JAVA怎么做点击按钮促发事件弹出浏览窗口选择excel文件读取,并显示到另外一个界面上,请给出主要代码
package com.excel;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
import javax.swing.JTextArea;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
/**
* 解析Excel的类
*/
public class ExcelOperate {
private JTextArea area;
private String fileName;
/**
* 构造方法传值
*
* @param area
* 显示Excel内容的位置
* @param fileName
* Excel文件名
*/
public ExcelOperate(JTextArea area, String fileName) {
this.area = area;
this.fileName = fileName;
}
/**
* 解析Excel文件
*/
public void parseExcel() {
File file = new File(fileName);
String[][] result = null;
try {
result = getData(file, 1);
} catch (IOException e) {
e.printStackTrace();
}
int rowLength = result.length;
for (int i = 0; i rowLength; i++) {
for (int j = 0; j result[i].length; j++) {
area.append(result[i][j] + "\t\t");
}
area.append("\n");
}
}
/**
* 读取Excel的内容,第一维数组存储的是一行中格列的值,二维数组存储的是多少个行
*
* @param file
* 读取数据的源Excel
* @param ignoreRows
* 读取数据忽略的行数,比喻行头不需要读入 忽略的行数为1
* @return 读出的Excel中数据的内容
* @throws FileNotFoundException
* @throws IOException
*/
public static String[][] getData(File file, int ignoreRows)
throws FileNotFoundException, IOException {
ListString[] result = new ArrayListString[]();
int rowSize = 0;
BufferedInputStream in = new BufferedInputStream(new FileInputStream(
file));
// 打开HSSFWorkbook
POIFSFileSystem fs = new POIFSFileSystem(in);
HSSFWorkbook wb = new HSSFWorkbook(fs);
HSSFCell cell = null;
for (int sheetIndex = 0; sheetIndex wb.getNumberOfSheets(); sheetIndex++) {
HSSFSheet st = wb.getSheetAt(sheetIndex);
// 第一行为标题,不取
for (int rowIndex = ignoreRows; rowIndex = st.getLastRowNum(); rowIndex++) {
HSSFRow row = st.getRow(rowIndex);
if (row == null) {
continue;
}
int tempRowSize = row.getLastCellNum() + 1;
if (tempRowSize rowSize) {
rowSize = tempRowSize;
}
String[] values = new String[rowSize];
Arrays.fill(values, "");
boolean hasValue = false;
for (short columnIndex = 0; columnIndex = row.getLastCellNum(); columnIndex++) {
String value = "";
cell = row.getCell(columnIndex);
if (cell != null) {
switch (cell.getCellType()) {
case HSSFCell.CELL_TYPE_STRING:
value = cell.getStringCellValue();
break;
case HSSFCell.CELL_TYPE_NUMERIC:
if (HSSFDateUtil.isCellDateFormatted(cell)) {
Date date = cell.getDateCellValue();
if (date != null) {
value = new SimpleDateFormat("yyyy-MM-dd")
.format(date);
} else {
value = "";
}
} else {
value = new DecimalFormat("0").format(cell
.getNumericCellValue());
}
break;
case HSSFCell.CELL_TYPE_FORMULA:
// 导入时如果为公式生成的数据则无值
if (!cell.getStringCellValue().equals("")) {
value = cell.getStringCellValue();
} else {
value = cell.getNumericCellValue() + "";
}
break;
case HSSFCell.CELL_TYPE_BLANK:
break;
case HSSFCell.CELL_TYPE_ERROR:
value = "";
break;
case HSSFCell.CELL_TYPE_BOOLEAN:
value = (cell.getBooleanCellValue() == true ? "Y"
: "N");
break;
default:
value = "";
}
}
if (columnIndex == 0 value.trim().equals("")) {
break;
}
values[columnIndex] = rightTrim(value);
hasValue = true;
}
if (hasValue) {
result.add(values);
}
}
}
in.close();
String[][] returnArray = new String[result.size()][rowSize];
for (int i = 0; i returnArray.length; i++) {
returnArray[i] = (String[]) result.get(i);
}
return returnArray;
}
/**
* 去掉字符串右边的空格
*
* @param str
* 要处理的字符串
* @return 处理后的字符串
*/
public static String rightTrim(String str) {
if (str == null) {
return "";
}
int length = str.length();
for (int i = length - 1; i = 0; i--) {
if (str.charAt(i) != 0x20) {
break;
}
length--;
}
return str.substring(0, length);
}
}
------------------------------------------------------------------------------------------
package com.excel;
import java.awt.BorderLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.UIManager;
import javax.swing.filechooser.FileNameExtensionFilter;
/**
* 主界面,按钮响应事件,文本域输出Excel内容
*/
public class OpenExcel extends JFrame implements ActionListener {
private JButton button;
private JScrollPane pane;
private JTextArea area;
public OpenExcel() {
super("解析Excel");
button = new JButton("点我选择Excel文件");
button.addActionListener(this);
area = new JTextArea();
pane = new JScrollPane(area);
this.add(button, BorderLayout.NORTH);
this.add(pane);
this.setSize(300, 300);
this.setLocationRelativeTo(null);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}
// 按钮事件
public void actionPerformed(ActionEvent e) {
JFileChooser chooser = new JFileChooser();// 文件选择对话框
chooser.setAcceptAllFileFilterUsed(false);// 取消所有文件过滤项
chooser.setFileFilter(new FileNameExtensionFilter("Excel文件", "xls"));// 设置只过滤扩展名为.xls的Excel文件
int i = chooser.showOpenDialog(this);// 打开窗口
if (i == JFileChooser.APPROVE_OPTION) {
this.setLocation(0, 0);
this.setSize(Toolkit.getDefaultToolkit().getScreenSize());
new ExcelOperate(area, chooser.getSelectedFile().getAbsolutePath())
.parseExcel();
}
}
public static void main(String[] args) throws Exception {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
new OpenExcel();
}
}
求java源代码。使用swing或AWT。实现功能:点击按钮,选择一个txt文本文件,并将txt中
搞定了
package com.monubia;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFileChooser;
import javax.swing.JTextArea;
import javax.swing.WindowConstants;
import javax.swing.SwingUtilities;
import javax.swing.filechooser.FileNameExtensionFilter;
/**
* This code was edited or generated using CloudGarden's Jigloo
* SWT/Swing GUI Builder, which is free for non-commercial
* use. If Jigloo is being used commercially (ie, by a corporation,
* company or business for any purpose whatever) then you
* should purchase a license for each developer using Jigloo.
* Please visit for details.
* Use of Jigloo implies acceptance of these licensing terms.
* A COMMERCIAL LICENSE HAS NOT BEEN PURCHASED FOR
* THIS MACHINE, SO JIGLOO OR THIS CODE CANNOT BE USED
* LEGALLY FOR ANY CORPORATE OR COMMERCIAL PURPOSE.
*/
public class Txt extends javax.swing.JFrame {
private JButton jButton_open;
private JTextArea jTextArea1;
/**
* Auto-generated main method to display this JFrame
*/
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
Txt inst = new Txt();
inst.setLocationRelativeTo(null);
inst.setVisible(true);
}
});
}
public Txt() {
super();
initGUI();
}
private void initGUI() {
try {
setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
getContentPane().setLayout(null);
{
jButton_open = new JButton();
getContentPane().add(jButton_open);
jButton_open.setText("Open");
jButton_open.setBounds(155, 114, 92, 49);
jButton_open.addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent evt) {
jButton_openMouseClicked(evt);
}
});
}
{
jTextArea1 = new JTextArea();
getContentPane().add(jTextArea1);
jTextArea1.setBounds(0, 0, 384, 262);
}
pack();
setSize(400, 300);
} catch (Exception e) {
//add your error handling code here
e.printStackTrace();
}
}
private void jButton_openMouseClicked(MouseEvent evt) {
//点击了打开
JFileChooser open=new JFileChooser();
FileNameExtensionFilter txt= new FileNameExtensionFilter("Txt File", "txt");
open.setFileFilter(txt);
int ret=open.showOpenDialog(this);
if(ret==JFileChooser.APPROVE_OPTION)
{
jButton_open.setOpaque(false);
jButton_open.setVisible(false);
System.out.println(open.getSelectedFile().getAbsolutePath());
try {
BufferedReader br=new BufferedReader(new FileReader(open.getSelectedFile().getAbsolutePath()));
String line=null;
while((line=br.readLine())!=null)
{
jTextArea1.append(line+"\n");
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
新闻名称:java按钮选择文件代码 java弹出文件选择框
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