java留言系統源碼

Ⅰ 求一個用java寫的簡單的記事本源代碼程序

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.awt.datatransfer.*;

class MyMenuBar extends MenuBar{
public MyMenuBar(Frame parent){
parent.setMenuBar(this);
}
public void addMenus(String [] menus){
for(int i=0;i<menus.length;i++)
add(new Menu(menus[i]));
}
public void addMenuItems(int menuNumber,String[] items){
for(int i=0;i<items.length;i++){
if(items[i]!=null)
getMenu(menuNumber).add(new MenuItem(items[i]));
else getMenu(menuNumber).addSeparator();
}
}
public void addActionListener(ActionListener al){
for(int i=0;i<getMenuCount();i++)
for(int j=0;j<getMenu(i).getItemCount();j++)
getMenu(i).getItem(j).addActionListener(al);
}
}

class MyFile{
private FileDialog fDlg;
public MyFile(Frame parent){
fDlg=new FileDialog(parent,"",FileDialog.LOAD);
}
private String getPath(){
return fDlg.getDirectory()+"\\"+fDlg.getFile();
}
public String getData() throws IOException{
fDlg.setTitle("打開");
fDlg.setMode(FileDialog.LOAD);
fDlg.setVisible(true);
BufferedReader br=new BufferedReader(new FileReader(getPath()));
StringBuffer sb=new StringBuffer();
String aline;
while((aline=br.readLine())!=null)
sb.append(aline+'\n');
br.close();
return sb.toString();
}
public void setData(String data) throws IOException{
fDlg.setTitle("保存");
fDlg.setMode(FileDialog.SAVE);
fDlg.setVisible(true);
BufferedWriter bw=new BufferedWriter(new FileWriter(getPath()));
bw.write(data);
bw.close();
}
}

class MyClipboard{
private Clipboard cb;
public MyClipboard(){
cb=Toolkit.getDefaultToolkit().getSystemClipboard();
}
public void setData(String data){
cb.setContents(new StringSelection(data),null);
}
public String getData(){
Transferable content=cb.getContents(null);
try{
return (String) content.getTransferData(DataFlavor.stringFlavor);
//DataFlavor.stringFlavor會將剪貼板中的字元串轉換成Unicode碼形式的String對象。
//DataFlavor類是與存儲在剪貼板上的數據的形式有關的類。
}catch(Exception ue){}
return null;
}
}

class MyFindDialog extends Dialog implements ActionListener{
private Label lFind=new Label("查找字元串");
private Label lReplace=new Label("替換字元串");
private TextField tFind=new TextField(10);
private TextField tReplace=new TextField(10);
private Button bFind=new Button("查找");
private Button bReplace=new Button("替換");
private TextArea ta;
public MyFindDialog(Frame owner,TextArea ta){
super(owner,"查找",false);
this.ta=ta;
setLayout(null);
lFind.setBounds(10,30,80,20);
lReplace.setBounds(10,70,80,20);
tFind.setBounds(90,30,90,20);
tReplace.setBounds(90,70,90,20);
bFind.setBounds(190,30,80,20);
bReplace.setBounds(190,70,80,20);
add(lFind);
add(tFind);
add(bFind);
add(lReplace);
add(tReplace);
add(bReplace);
setResizable(false);
bFind.addActionListener(this);
bReplace.addActionListener(this);
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
MyFindDialog.this.dispose();
}
});
}//構造函數結束
public void showFind(){
setTitle("查找");
setSize(280,60);
setVisible(true);
}
public void showReplace(){
setTitle("查找替換");
setSize(280,110);
setVisible(true);
}
private void find(){
String text=ta.getText();
String str=tFind.getText();
int end=text.length();
int len=str.length();
int start=ta.getSelectionEnd();
if(start==end) start=0;
for(;start<=end-len;start++){
if(text.substring(start,start+len).equals(str)){
ta.setSelectionStart(start);
ta.setSelectionEnd(start+len);
return;
}
}
//若找不到待查字元串，則將游標置於末尾
ta.setSelectionStart(end);
ta.setSelectionEnd(end);
}

public Button getBFind() {
return bFind;
}
private void replace(){
String str=tReplace.getText();
if(ta.getSelectedText().equals(tFind.getText()))
ta.replaceRange(str,ta.getSelectionStart(),ta.getSelectionEnd());
else find();
}

public void actionPerformed(ActionEvent e) {
if(e.getSource()==bFind)
find();
else if(e.getSource()==bReplace)
replace();
}
}

public class MyMemo extends Frame implements ActionListener{
private TextArea editor=new TextArea(); //可編輯的TextArea
private MyFile mf=new MyFile(this);//MyFile對象
private MyClipboard cb=new MyClipboard();
private MyFindDialog findDlg=new MyFindDialog(this,editor);

public MyMemo(String title){ //構造函數
super(title);
MyMenuBar mb=new MyMenuBar(this);
//添加需要的菜單及菜單項
mb.addMenus(new String[]{"文件","編輯","查找","幫助"});
mb.addMenuItems(0,new String[]{"新建","打開","保存",null,"全選"});
mb.addMenuItems(1,new String[]{"剪貼","復制","粘貼","清除",null,"全選"});
mb.addMenuItems(2,new String[]{"查找",null,"查找替換"});
mb.addMenuItems(3,new String[]{"我的記事本信息"});

add(editor); //為菜單項注冊動作時間監聽器
mb.addActionListener(this);

addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
MyMemo.this.dispose();
}
}); //分號不能忘了
} //構造函數完

public void actionPerformed(ActionEvent e){
String selected=e.getActionCommand(); //獲取菜單項標題
if(selected.equals("新建"))
editor.setText("");
else if(selected.equals("打開")){
try{
editor.setText(mf.getData());
}catch(IOException ie){}
}
else if(selected.equals("保存")){
try{
mf.setData(editor.getText());
}catch(IOException ie){}
}
else if(selected.equals("退出")){
dispose();
}
else if(selected.equals("剪貼")){
//將選中的字元串復制到剪貼板中並清除字元串
cb.setData(editor.getSelectedText());
editor.replaceRange("",editor.getSelectionStart(),editor.getSelectionEnd());
}
else if(selected.equals("復制")){
cb.setData(editor.getSelectedText());
}
else if(selected.equals("粘貼")){
String str=cb.getData();
editor.replaceRange(str,editor.getSelectionStart(),editor.getSelectionEnd());
//粘貼在游標位置
}
else if(selected.equals("清除")){
editor.replaceRange("",editor.getSelectionStart(),editor.getSelectionEnd());
}
else if(selected.equals("全選")){
editor.setSelectionStart(0);
editor.setSelectionEnd(editor.getText().length());
}
else if(selected.equals("查找")){
findDlg.showFind();
}
else if(selected.equals("查找替換")){
findDlg.showReplace();
}
}

public static void main(String[] args){
MyMemo memo=new MyMemo("記事本");
memo.setSize(650,450);
memo.setVisible(true);
}
}

Ⅱ 什麼是java源代碼 怎麼查看

不知道你說的是瀏覽器的還是什麼的，
如果是瀏覽器的那麼簡單找到工具-查看源代碼，你就能看見代碼了，
還有一個就是被編譯成class文件的java用反編譯工具可以看到源代碼，
如果以上都不是你想要的答案，那麼你所說的代碼就是程序員寫好的代碼文件

Ⅲ 求一個專業的Java源碼網站

Java Code Examples, Tips and Articles

http://www.javadb.com/

Ⅳ 急求一段簡單的java源代碼（用戶名、密碼操作界面）

下面的程序可以直接通過編譯運行，自己尋找要用到的代碼段。

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;

import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;

public class UserLogin extends JPanel implements ActionListener{
JTextField userjt=null;//用戶輸入框
JPasswordField pwdjt=null;
JTextField sysUserjt=null;//系統顯示用戶名輸入框
JTextField sysPwdjt=null;
public UserLogin(){
super(new GridLayout(1,2));
JPanel userPanel=new JPanel();//用戶界面，左邊
userPanel.setLayout(new BoxLayout(userPanel,BoxLayout.Y_AXIS));
this.add(userPanel);
JPanel userUpPanel=new JPanel();//用戶界面上半部分
userPanel.add(userUpPanel);
JPanel userDownPanel=new JPanel();//用戶界面下半部分
userPanel.add(userDownPanel);

JPanel sysPanel=new JPanel();//系統界面，右邊
sysPanel.setLayout(new BoxLayout(sysPanel,BoxLayout.Y_AXIS));
this.add(sysPanel);
JPanel sysUserPanel=new JPanel();//系統界面上半部分
sysPanel.add(sysUserPanel);
JPanel sysPwdPanel=new JPanel();//系統界面下半部分
sysPanel.add(sysPwdPanel);

userjt=new JTextField(5);
userjt.setText("用戶名");
userUpPanel.add(userjt);
pwdjt=new JPasswordField(5);
pwdjt.setText("密碼");
pwdjt.setEchoChar('\0');
userDownPanel.add(pwdjt);
JLabel sysUserjl=new JLabel("用戶名為：");
sysUserPanel.add(sysUserjl);
sysUserjt=new JTextField(5);
sysUserPanel.add(sysUserjt);
JLabel sysPwdjl=new JLabel("密碼為：");
sysPwdPanel.add(sysPwdjl);
sysPwdjt=new JTextField(5);
sysPwdPanel.add(sysPwdjt);

userjt.addActionListener(this);
pwdjt.addActionListener(this);
userjt.addFocusListener(new FocusListener(){
public void focusGained(FocusEvent e) {
if(userjt.getText().equals("用戶名"))
userjt.setText("");
}
public void focusLost(FocusEvent e) {
if(userjt.getText().equals(""))
userjt.setText("用戶名");

}});
pwdjt.addFocusListener(new FocusListener(){
public void focusGained(FocusEvent e) {
if(new String(pwdjt.getPassword()).equals("密碼")){
pwdjt.setText("");
pwdjt.setEchoChar('*');
}
}
public void focusLost(FocusEvent e) {
if(new String(pwdjt.getPassword()).equals("")){
pwdjt.setText("密碼");
pwdjt.setEchoChar('\0');
}

}});
}
public void actionPerformed(ActionEvent e) {
if(e.getSource().equals(userjt)){
pwdjt.requestFocus();
}else{
if(new String(pwdjt.getPassword()).equals("")||userjt.getText().equals("")||userjt.getText().equals("用戶名")) return;
sysUserjt.setText(userjt.getText());
sysPwdjt.setText(new String(pwdjt.getPassword()));
try {
writetoFile();
} catch (IOException e1) {
System.out.println("寫入文件發生異常！");
e1.printStackTrace();
}
}
}
private void writetoFile() throws IOException{
File f=new File("User_Psd.txt");
// if(!f.exists()) f.createNewFile();
RandomAccessFile accessFile=new RandomAccessFile(f, "rw");
accessFile.seek(accessFile.length());
accessFile.write(("user:"+userjt.getText()+"\r\npassword:"+new String(pwdjt.getPassword())+"\r\n\r\n").getBytes());
}

public static void main(String args[]){
JFrame jf=new JFrame("用戶登陸模塊測試");
jf.setDefaultCloseOperation(jf.EXIT_ON_CLOSE);
jf.add(new UserLogin());
jf.setBounds(400,300,280,150);
jf.setVisible(true);
}

}

Ⅳ 急求java學生信息管理系統源代碼，帶有連接資料庫的，萬分感謝

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Container;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JToolBar;
import javax.swing.SwingConstants;
public class MainFrame extends JFrame implements ActionListener{
InsertPanel ip = null;
SelectPanel sp = null;
JPanel pframe;
JButton jb1,jb2,jb3;
JMenuItem jm11,jm21,jm22,jm23,jm31,jm32,jm41,jm42;
CardLayout clayout;
public MainFrame(String s){
super(s);
JMenuBar mb = new JMenuBar();
this.setJMenuBar(mb);
JMenu m1 = new JMenu("系統");
JMenu m2 = new JMenu("基本信息");
JMenu m3 = new JMenu("成績");
JMenu m4 = new JMenu("獎懲");
mb.add(m1);
mb.add(m2);
mb.add(m3);
mb.add(m4);
jm11 = new JMenuItem("退出系統");
jm21 = new JMenuItem("輸入");
jm22 = new JMenuItem("查詢");
jm23 = new JMenuItem("更改");
jm31 = new JMenuItem("輸入成績");
jm32 = new JMenuItem("查詢成績");
jm41 = new JMenuItem("獎勵");
jm42 = new JMenuItem("處分");
m1.add(jm11);
m2.add(jm21);
m2.add(jm22);
m2.add(jm23);
m3.add(jm31);
m3.add(jm32);
m4.add(jm41);
m4.add(jm42);
Icon i1 = new ImageIcon();
Icon i2 = new ImageIcon();
Icon i3 = new ImageIcon();
jb1 = new JButton(i1);
jb1.setToolTipText("輸入");
jb2 = new JButton(i2);
jb2.setToolTipText("查詢");
jb3 = new JButton(i3);
jb3.setToolTipText("退出");
JToolBar tb = new JToolBar("系統工具");
tb.add(jb1);
tb.add(jb2);
tb.add(jb3);
add(tb,BorderLayout.NORTH);
jm11.addActionListener(this);
jm21.addActionListener(this);
jm22.addActionListener(this);
jb1.addActionListener(this);
jb2.addActionListener(this);
jb3.addActionListener(this);
clayout = new CardLayout();
pframe = new JPanel(clayout);
add(pframe);
JPanel mainp = new JPanel(new BorderLayout());
JLabel mainl = new JLabel("學生信息管理平台",SwingConstants.CENTER);
mainl.setFont(new Font("serif",Font.BOLD,30));
mainp.add(mainl);
pframe.add(mainp,"main");
clayout.show(pframe, "main");
}
public void actionPerformed(ActionEvent e){
if(e.getSource() == jm21 || e.getSource() == jb1){
if(ip == null){
ip= new InsertPanel();
pframe.add(ip,"insert");
}
clayout.show(pframe, "insert");
this.setTitle("輸入學生信息");
}
else if(e.getSource() == jm22 || e.getSource() == jb2){
if(sp == null){
sp= new SelectPanel();
pframe.add(sp,"select");
}
clayout.show(pframe, "select");
this.setTitle("查詢學生信息");
}
else if(e.getSource() == jm11 || e.getSource() == jb3){
System.exit(0);
}
}
}
第二個：
import javax.swing.JFrame;
public class MainTest {
public static void main(String [] args){
MainFrame f = new MainFrame("學生信息管理平台");
f.setSize(400,300);
f.setLocation(350,250);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
}
第二個：
import java.sql.Connection;
import java.sql.DriverManager;
public class MySQLConnection {
static Connection getCon(){
Connection con = null;
try{
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection("jdbc:mysql://localhost/test","root","123");
}
catch(Exception e){
System.out.println("建立資料庫連接遇到異常！");
}
return con;
}
}
第四個：
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
public class SelectPanel extends JPanel implements ActionListener{
JButton jb;
JTextField jt;
JTextField jt1,jt2,jt3,jt4;
public SelectPanel(){
JLabel jl = new JLabel("請輸入學號:",SwingConstants.CENTER);
jt = new JTextField();
jb = new JButton("確定");
JPanel jp1 = new JPanel(new GridLayout(1,3));
jp1.add(jl);
jp1.add(jt);
jp1.add(jb);
JLabel j1,j2,j3,j4;
j1 = new JLabel("學號:",SwingConstants.CENTER);
j2 = new JLabel("姓名:",SwingConstants.CENTER);
j3 = new JLabel("性別:",SwingConstants.CENTER);
j4 = new JLabel("年齡:",SwingConstants.CENTER);
jt1 = new JTextField(6);
jt1.setEditable(false);
jt2 = new JTextField(6);
jt2.setEditable(false);
jt3 = new JTextField(6);
jt3.setEditable(false);
jt4 = new JTextField(6);
jt4.setEditable(false);
JPanel jp2 = new JPanel(new BorderLayout());
JPanel jp3 = new JPanel(new GridLayout(4,2));
jp2.add(new JLabel(""),BorderLayout.NORTH);
jp3.add(j1);
jp3.add(jt1);
jp3.add(j2);
jp3.add(jt2);
jp3.add(j3);
jp3.add(jt3);
jp3.add(j4);
jp3.add(jt4);
jp2.add(jp3);
this.setLayout(new BorderLayout());
add(jp1,BorderLayout.NORTH);
add(jp2);
jb.addActionListener(this);
}
public void actionPerformed(ActionEvent e){
if(e.getSource() == jb){
String stuNo = jt.getText().trim();
Student s = new Student();
boolean b = true;
try{
b = s.selectByStuNo(stuNo);
}
catch(Exception ex){
System.out.println("查詢學生信息遇到異常!");
}
if(b){
jt1.setText(s.getStuNo());
jt2.setText(s.getName());
jt3.setText(s.getGender());
int a = s.getAge();
Integer i = new Integer(a);
jt4.setText(i.toString());
}
else{
JOptionPane.showMessageDialog(null, "無此學生!");
}
}
}

}
第五個：
import javax.swing.JFrame;
public class SelectTest {
public static void main(String [] args){
JFrame f = new JFrame("查詢學生信息");
SelectPanel p = new SelectPanel();
f.add(p);
f.setSize(400,300);
f.setLocation(300,250);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
}
第六個：
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
public class Student {
String stuNo;
String name;
String gender;
int age;
public Student(){}
public Student(String stuNo,String name,String gender, int age){
this.stuNo = stuNo;
this.name = name;
this.gender = gender;
this.age = age;
}
public String getStuNo(){
return stuNo;
}
public void setStuNo(String stuNo){
this.stuNo = stuNo;
}
public String getName(){
return name;
}
public void setName(String name){
this.name = name;
}
public String getGender(){
return gender;
}
public void setGender(String gender){
this.gender = gender;
}
public int getAge(){
return age;
}
public void setAge(int age){
this.age = age;
}
public boolean insertStudent(){
boolean b = true;
try{
Connection con = MySQLConnection.getCon();
Statement statement = con.createStatement();
String sql = "insert into student values('" + stuNo + "','" + name +"','" + gender + "'," + age + ")";
sql = new String(sql.getBytes("gb2312"),"ISO8859_1");
statement.executeUpdate(sql);
con.close();
}
catch(Exception e){
b = false;
System.out.println("插入資料庫遇到異常！");
}
return b;
}
public boolean selectByStuNo(String stuNo)throws Exception{
boolean b = true;
Connection con = MySQLConnection.getCon();
Statement statement = con.createStatement();
String sql = "select * from student where stuNo =" + stuNo;
ResultSet rs = statement.executeQuery(sql);
if(rs != null && rs.next()){
String no = rs.getString(1);
this.setStuNo(no);
String n = rs.getString(2);
n = new String(n.getBytes("ISO8859_1"),"gb2312");
this.setName(n);
String g = rs.getString(3);
g = new String (g.getBytes("ISO8859_1"),"gb2312");
this.setGender(g);
this.setAge(rs.getInt(4));
b = true;
}
rs.close();
statement.close();
con.close();
return b;
}
}
資料庫你自己弄吧，我沒時間弄了！初學得多動手哦