另存为java代码实现 java实现文件另存为
java编写的记事本的保存和另存为功能
可以通过“FileOutputStream”创建文件实例,之后过“OutputStreamWriter”流的形式进行存储,举例:
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OutputStreamWriter
pw
=
null;//定义一个流
pw
=
new
OutputStreamWriter(new
FileOutputStream(“D:/test.txt”),"GBK");//确认流的输出文件和编码格式,此过程创建了“test.txt”实例
pw.write("我是要写入到记事本文件的内容");//将要写入文件的内容,可以多次write
pw.close();//关闭流
解释:文件流用完之后必须及时通过close方法关闭,否则会一直处于打开状态,直至程序停止,增加系统负担。
如何用Java实现另存为
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.Calendar;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
public class BakTo extends JFrame implements ActionListener {
JLabel l1 = new JLabel("原始文件");
JTextField t1 = new JTextField(40);
JButton b1 = new JButton("选择");
JLabel l2 = new JLabel("保存目录");
JTextField t2 = new JTextField(40);
JButton b2 = new JButton("保存");
JFileChooser j1 = new JFileChooser();
JFileChooser j2 = new JFileChooser();
static File fileFlag = new File("");
public BakTo() {
setBounds(200, 200, 600, 140);
setLayout(new FlowLayout());
add(l1);
add(t1);
add(b1);
add(l2);
add(t2);
add(b2);
b1.addActionListener(this);
b2.addActionListener(this);
setResizable(false);
setVisible(true);
validate();
}
public void actionPerformed(ActionEvent e) {
try {
if (e.getSource() == b1) {
int n = j1.showOpenDialog(null);
String filename = j1.getSelectedFile().toString();
if (n == JFileChooser.APPROVE_OPTION) {
t1.setText(filename);
fileFlag = new File(filename);
}
}
else if (e.getSource() == b2) {
j2.setCurrentDirectory(fileFlag);// 设置打开对话框的默认路径
j2.setSelectedFile(fileFlag);// 设置选中原来的文件
int n = j2.showSaveDialog(null);
String filename2 = j2.getSelectedFile().toString();
if(filename2.indexOf(".")!=-1){
filename2=filename2.substring(0,filename2.indexOf("."));
}
// 以下两句是获得原文件的扩展名
int flag = t1.getText().lastIndexOf(".");
String kuozhan = t1.getText().substring(flag);
String date = getDate();// 取得当前日期
if (n == JFileChooser.APPROVE_OPTION) {
t2.setText(filename2 +date+ kuozhan);// 把日期和扩展名添加到原来文件的后面
}
int b;
char[] t = new char[25];
// 这里我改用了文件流
FileInputStream input = new FileInputStream(t1.getText());
FileOutputStream output = new FileOutputStream(filename2+date
+ kuozhan);// 把扩展名添加到原来文件的后面
int in = input.read();
while (in != -1) {
output.write(in);
in = input.read();
}
input.close();
output.close();
}
} catch (Exception x) {
System.out.println(x);
}
}
public String getDate() {
Calendar rightNow = Calendar.getInstance();
System.out.println(rightNow.toString());
int year = rightNow.YEAR;
int date = rightNow.DATE;
int month = rightNow.MONTH + 1;
String d = year + "年" + month + "月" + date + "日";
return d;
}
public static void main(String args[]) {
BakTo c1 = new BakTo();
}
}
用java文件对话框实现文件另存为
我觉得用一个文件复制的类就可以实现备份,我大概写了一个,基本功能可以实现,但是总觉得好怪
你可以给JTextField t1 一个初始路径,那样,如果每次都是备份同一个文件直接点保存选路径就可以,如果想备份其他文件再选其他文件就可以了
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.Calendar;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
public class BakTo extends JFrame implements ActionListener {
JLabel l1 = new JLabel("原始文件");
JTextField t1 = new JTextField(40);
JButton b1 = new JButton("选择");
JLabel l2 = new JLabel("保存目录");
JTextField t2 = new JTextField(40);
JButton b2 = new JButton("保存");
JFileChooser j1 = new JFileChooser();
JFileChooser j2 = new JFileChooser();
static File fileFlag = new File("");
public BakTo() {
setBounds(200, 200, 600, 140);
setLayout(new FlowLayout());
add(l1);
add(t1);
add(b1);
add(l2);
add(t2);
add(b2);
b1.addActionListener(this);
b2.addActionListener(this);
setResizable(false);
setVisible(true);
validate();
}
public void actionPerformed(ActionEvent e) {
try {
if (e.getSource() == b1) {
int n = j1.showOpenDialog(null);
String filename = j1.getSelectedFile().toString();
if (n == JFileChooser.APPROVE_OPTION) {
t1.setText(filename);
fileFlag = new File(filename);
}
}
else if (e.getSource() == b2) {
j2.setCurrentDirectory(fileFlag);// 设置打开对话框的默认路径
j2.setSelectedFile(fileFlag);// 设置选中原来的文件
int n = j2.showSaveDialog(null);
String filename2 = j2.getSelectedFile().toString();
if(filename2.indexOf(".")!=-1){
filename2=filename2.substring(0,filename2.indexOf("."));
}
// 以下两句是获得原文件的扩展名
int flag = t1.getText().lastIndexOf(".");
String kuozhan = t1.getText().substring(flag);
String date = getDate();// 取得当前日期
if (n == JFileChooser.APPROVE_OPTION) {
t2.setText(filename2 +date+ kuozhan);// 把日期和扩展名添加到原来文件的后面
}
int b;
char[] t = new char[25];
// 这里我改用了文件流
FileInputStream input = new FileInputStream(t1.getText());
FileOutputStream output = new FileOutputStream(filename2+date
+ kuozhan);// 把扩展名添加到原来文件的后面
int in = input.read();
while (in != -1) {
output.write(in);
in = input.read();
}
input.close();
output.close();
}
} catch (Exception x) {
System.out.println(x);
}
}
public String getDate() {
Calendar rightNow = Calendar.getInstance();
System.out.println(rightNow.toString());
int year = rightNow.YEAR;
int date = rightNow.DATE;
int month = rightNow.MONTH + 1;
String d = year + "年" + month + "月" + date + "日";
return d;
}
public static void main(String args[]) {
BakTo c1 = new BakTo();
}
}
java图形用户界面的选择一个文件并复制(另存为)的代码,麻烦了。
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import java.awt.Font;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.Color;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import javax.swing.JFileChooser;
public class CopyFile {
private JFrame frame;
private JTextField textField;
private JTextField textField_1;
private JFileChooser chooser;
private String readPath;
private String writePath;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
CopyFile window = new CopyFile();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public CopyFile() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 545, 277);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(null);
JLabel label = new JLabel("\u6587\u4EF6\uFF1A");
label.setFont(new Font("黑体", Font.BOLD, 18));
label.setBounds(26, 68, 57, 25);
frame.getContentPane().add(label);
JLabel lblNewLabel = new JLabel("\u4FDD\u5B58\u76EE\u5F55\uFF1A");
lblNewLabel.setFont(new Font("黑体", Font.BOLD, 18));
lblNewLabel.setBounds(10, 119, 95, 25);
frame.getContentPane().add(lblNewLabel);
textField = new JTextField();
textField.setBounds(105, 68, 299, 25);
frame.getContentPane().add(textField);
textField.setColumns(10);
textField_1 = new JTextField();
textField_1.setBounds(105, 121, 299, 25);
frame.getContentPane().add(textField_1);
textField_1.setColumns(10);
chooser = new JFileChooser();
chooser.setFileSelectionMode(JFileChooser.FILES_ONLY);// 设置选择模式,既可以选择文件又可以选择文件夹
JButton button = new JButton("\u6253\u5F00");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int index = chooser.showOpenDialog(null);
chooser.setDialogType(JFileChooser.OPEN_DIALOG);
chooser.setMultiSelectionEnabled(false);
chooser.setAcceptAllFileFilterUsed(false);
if (index == JFileChooser.APPROVE_OPTION) {
// 把获取到的文件的绝对路径显示在文本编辑框中
textField.setText(chooser.getSelectedFile()
.getAbsolutePath());
readPath = textField.getText();
}
}
});
button.setFont(new Font("黑体", Font.BOLD, 18));
button.setBounds(432, 67, 87, 26);
frame.getContentPane().add(button);
JButton button_1 = new JButton("\u6D4F\u89C8");
button_1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int index = chooser.showSaveDialog(null);
chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
chooser.setDialogType(JFileChooser.SAVE_DIALOG);
chooser.setMultiSelectionEnabled(false);
chooser.setAcceptAllFileFilterUsed(false);
if (index == JFileChooser.APPROVE_OPTION) {
// 把获取到的文件的绝对路径显示在文本编辑框中
textField_1.setText(chooser.getSelectedFile()
.getAbsolutePath());
writePath = textField_1.getText() + "\\";
}
}
});
button_1.setFont(new Font("黑体", Font.BOLD, 18));
button_1.setBounds(432, 118, 87, 26);
frame.getContentPane().add(button_1);
JButton button_2 = new JButton("\u53E6\u5B58\u4E3A");
button_2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
readPath = textField.getText();
writePath = textField_1.getText() + "\\";
if(copyFile(readPath, writePath)== -1){//原文件不存在
JOptionPane.showMessageDialog(null, "源文件不存在", "警告", JOptionPane.ERROR_MESSAGE);
}
}
});
button_2.setForeground(Color.RED);
button_2.setFont(new Font("黑体", Font.BOLD, 18));
button_2.setBounds(213, 180, 93, 34);
frame.getContentPane().add(button_2);
}
/*
* *
* 复制单个文件
*
* @param oldPath String 原文件路径 如:c:/fqf.txt
*
* @param newPath String 复制后路径 如:f:/fgf.txt
*
* @return int 0表示成功,-1表示原文件不存在,-2表示未知错误。
*/
public int copyFile(String oldPath, String newPath) {
try {
int bytesum = 0;
int byteread = 0;
File oldfile = new File(oldPath);
if (oldfile.exists()) { // 文件存在时
InputStream inStream = new FileInputStream(oldPath); // 读入原文件
System.out.println(newPath);
if(isExist(newPath)){
FileOutputStream fs = new FileOutputStream(newPath);
byte[] buffer = new byte[1444];
while ((byteread = inStream.read(buffer)) != -1) {
bytesum += byteread; // 字节数 文件大小
System.out.println(bytesum);
fs.write(buffer, 0, byteread);
}
inStream.close();
fs.close();
return 0;
}else{
return -2;
}
}
return -1;
} catch (Exception e) {
System.out.println("复制单个文件操作出错");
e.printStackTrace();
return -2;
}
}
public static boolean isExist(String filePath) {
String paths[] = filePath.split("\\\\");
String dir = paths[0];
for (int i = 0; i paths.length - 2; i++) {// 注意此处循环的长度
try {
dir = dir + "/" + paths[i + 1];
File dirFile = new File(dir);
if (!dirFile.exists()) {
dirFile.mkdir();
System.out.println("创建目录为:" + dir);
}
} catch (Exception err) {
System.err.println("ELS - Chart : 文件夹创建发生异常");
}
}
File fp = new File(filePath);
if (!fp.exists()) {
return true; // 文件不存在,执行下载功能
} else {
return false; // 文件存在不做处理
}
}
}
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