java留言板程序源代码,java留言板功能齐全源码

求java版画图程序的源代码

找到了，很久以前写的一个简单画图，呵呵～当时要求用AWT写，很难受。

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package net.miqiang.gui;

import java.awt.BasicStroke;

import java.awt.BorderLayout;

import java.awt.Button;

import java.awt.Color;

import java.awt.Cursor;

import java.awt.Dimension;

import java.awt.Frame;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.GridLayout;

import java.awt.Label;

import java.awt.Panel;

import java.awt.RenderingHints;

import java.awt.Toolkit;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.awt.event.MouseListener;

import java.awt.event.MouseMotionListener;

import java.awt.event.WindowAdapter;

import java.awt.event.WindowEvent;

import java.awt.image.BufferedImage;

/**

* 简单画图板程序

* 好久没用 AWT 了，写起来真别扭，如果用 swing 会很舒服，有空再改写吧。

*

* @author 米强

*

*/

public class TestMain extends Frame {

// 画板

private Palette palette = null;

// 显示当前颜色的面板

private Panel nonceColor = null;

// 画笔粗细

private Label drawWidth = null;

// 画笔端点的装饰

private Label drawCap = null;

// 选取颜色按钮的监听事件类

private ButtonColorAction buttonColorAction = null;

// 鼠标进入按钮后光标样式的监听事件类

private ButtonCursor buttonCursor = null;

// 画笔样式的监听事件

private ButtonStrokeAction buttonStrokeAction = null;

/**

* 构造方法

*

*/

public TestMain() {

// 设置标题栏文字

super("简易画图板");

// 构造一个画图板

palette = new Palette();

Panel pane = new Panel(new GridLayout(2, 1));

// 画笔颜色选择器

Panel paneColor = new Panel(new GridLayout(1, 13));

// 12 个颜色选择按钮

Button [] buttonColor = new Button[12];

Color [] color = {Color.black, Color.blue, Color.cyan, Color.darkGray, Color.gray, Color.green, Color.magenta, Color.orange, Color.pink, Color.red, Color.white, Color.yellow};

// 显示当前颜色的面板

nonceColor = new Panel();

nonceColor.setBackground(Color.black);

paneColor.add(nonceColor);

buttonColorAction = new ButtonColorAction();

buttonCursor = new ButtonCursor();

for(int i = 0; i buttonColor.length; i++){

buttonColor[i] = new Button();

buttonColor[i].setBackground(color[i]);

buttonColor[i].addActionListener(buttonColorAction);

buttonColor[i].addMouseListener(buttonCursor);

paneColor.add(buttonColor[i]);

}

pane.add(paneColor);

// 画笔颜色选择器

Panel paneStroke = new Panel(new GridLayout(1, 13));

// 控制画笔样式

buttonStrokeAction = new ButtonStrokeAction();

Button [] buttonStroke = new Button[11];

buttonStroke[0] = new Button("1");

buttonStroke[1] = new Button("3");

buttonStroke[2] = new Button("5");

buttonStroke[3] = new Button("7");

buttonStroke[4] = new Button("9");

buttonStroke[5] = new Button("11");

buttonStroke[6] = new Button("13");

buttonStroke[7] = new Button("15");

buttonStroke[8] = new Button("17");

buttonStroke[9] = new Button("■");

buttonStroke[10] = new Button("●");

drawWidth = new Label("3", Label.CENTER);

drawCap = new Label("●", Label.CENTER);

drawWidth.setBackground(Color.lightGray);

drawCap.setBackground(Color.lightGray);

paneStroke.add(drawWidth);

for(int i = 0; i buttonStroke.length; i++){

paneStroke.add(buttonStroke[i]);

buttonStroke[i].addMouseListener(buttonCursor);

buttonStroke[i].addActionListener(buttonStrokeAction);

if(i = 8){

buttonStroke[i].setName("width");

}else{

buttonStroke[i].setName("cap");

}

if(i == 8){

paneStroke.add(drawCap);

}

}

pane.add(paneStroke);

// 将画笔颜色选择器添加到窗体中

this.add(pane, BorderLayout.NORTH);

// 将画图板添加到窗体中

this.add(palette);

// 添加窗口监听，点击关闭按钮时退出程序

this.addWindowListener(new WindowAdapter() {

public void windowClosing(WindowEvent e) {

System.exit(0);

}

});

// 设置窗体 ICON 图标

this.setIconImage(Toolkit.getDefaultToolkit().createImage("images/palette.png"));

// 设置窗口的大小

this.setSize(new Dimension(400, 430));

// 设置窗口位置，处于屏幕正中央

this.setLocationRelativeTo(null);

// 显示窗口

this.setVisible(true);

}

/**

* 程序入口

*

* @param args

* 字符串数组参数

*/

public static void main(String[] args) {

new TestMain();

}

/**

* 选取颜色按钮的监听事件类

* @author 米强

*

*/

class ButtonColorAction implements ActionListener {

public void actionPerformed(ActionEvent e) {

Color color_temp = ((Button)e.getSource()).getBackground();

nonceColor.setBackground(color_temp);

palette.setColor(color_temp);

}

}

/**

* 鼠标进入按钮变换光标样式监听事件类

* @author 米强

*

*/

class ButtonCursor extends MouseAdapter {

public void mouseEntered(MouseEvent e) {

((Button)e.getSource()).setCursor(new Cursor(Cursor.HAND_CURSOR));

}

public void mouseExited(MouseEvent e) {

((Button)e.getSource()).setCursor(new Cursor(Cursor.DEFAULT_CURSOR));

}

}

/**

* 设置画笔的监听事件类

* @author 米强

*

*/

class ButtonStrokeAction implements ActionListener {

public void actionPerformed(ActionEvent e) {

Button button_temp = (Button) e.getSource();

String name = button_temp.getName();

if(name.equalsIgnoreCase("width")){

drawWidth.setText(button_temp.getLabel());

palette.setStroke(Float.parseFloat(button_temp.getLabel()));

}else if(name.equalsIgnoreCase("cap")){

drawCap.setText(button_temp.getLabel());

if(button_temp.getLabel().equals("■")){

palette.setStroke(BasicStroke.CAP_SQUARE);

}else if(button_temp.getLabel().equals("●")){

palette.setStroke(BasicStroke.CAP_ROUND);

}

}

}

}

}

/**

* 画板类

*

* @author 米强

*

*/

class Palette extends Panel implements MouseListener, MouseMotionListener {

// 鼠标 X 坐标的位置

private int mouseX = 0;

// 上一次 X 坐标位置

private int oldMouseX = 0;

// 鼠标 Y 坐标的位置

private int mouseY = 0;

// 上一次 Y 坐标位置

private int oldMouseY = 0;

// 画图颜色

private Color color = null;

// 画笔样式

private BasicStroke stroke = null;

// 缓存图形

private BufferedImage image = null;

/**

* 构造一个画板类

*

*/

public Palette() {

this.addMouseListener(this);

this.addMouseMotionListener(this);

// 默认黑色画笔

color = new Color(0, 0, 0);

// 设置默认画笔样式

stroke = new BasicStroke(3.0f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);

// 建立 1280 * 1024 的 RGB 缓存图象

image = new BufferedImage(1280, 1024, BufferedImage.TYPE_INT_RGB);

// 设置颜色

image.getGraphics().setColor(Color.white);

// 画背景

image.getGraphics().fillRect(0, 0, 1280, 1024);

}

/**

* 重写 paint 绘图方法

*/

public void paint(Graphics g) {

super.paint(g);

// 转换为 Graphics2D

Graphics2D g2d = (Graphics2D) g;

// 获取缓存图形 Graphics2D

Graphics2D bg = image.createGraphics();

// 图形抗锯齿

bg.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

// 设置绘图颜色

bg.setColor(color);

// 设置画笔样式

bg.setStroke(stroke);

// 画线，从上一个点到新的点

bg.drawLine(oldMouseX, oldMouseY, mouseX, mouseY);

// 将缓存中的图形画到画板上

g2d.drawImage(image, 0, 0, this);

}

/**

* 重写 update 方法

*/

public void update(Graphics g) {

this.paint(g);

}

/**

* @return stroke

*/

public BasicStroke getStroke() {

return stroke;

}

/**

* @param stroke 要设置的 stroke

*/

public void setStroke(BasicStroke stroke) {

this.stroke = stroke;

}

/**

* 设置画笔粗细

* @param width

*/

public void setStroke(float width) {

this.stroke = new BasicStroke(width, stroke.getEndCap(), stroke.getLineJoin());

}

/**

* 设置画笔端点的装饰

* @param cap 参考 java.awt.BasicStroke 类静态字段

*/

public void setStroke(int cap) {

this.stroke = new BasicStroke(stroke.getLineWidth(), cap, stroke.getLineJoin());

}

/**

* @return color

*/

public Color getColor() {

return color;

}

/**

* @param color 要设置的 color

*/

public void setColor(Color color) {

this.color = color;

}

public void mouseClicked(MouseEvent mouseEvent) {

}

/**

* 鼠标按下

*/

public void mousePressed(MouseEvent mouseEvent) {

this.oldMouseX = this.mouseX = mouseEvent.getX();

this.oldMouseY = this.mouseY = mouseEvent.getY();

repaint();

}

public void mouseReleased(MouseEvent mouseEvent) {

}

/**

* 鼠标进入棋盘

*/

public void mouseEntered(MouseEvent mouseEvent) {

this.setCursor(new Cursor(Cursor.CROSSHAIR_CURSOR));

}

/**

* 鼠标退出棋盘

*/

public void mouseExited(MouseEvent mouseEvent) {

this.setCursor(new Cursor(Cursor.DEFAULT_CURSOR));

}

/**

* 鼠标拖动

*/

public void mouseDragged(MouseEvent mouseEvent) {

this.oldMouseX = this.mouseX;

this.oldMouseY = this.mouseY;

this.mouseX = mouseEvent.getX();

this.mouseY = mouseEvent.getY();

repaint();

}

public void mouseMoved(MouseEvent mouseEvent) {

}

}

开源里有没有留言板的源代码，JAVA的

绝对开源，绝对明了的留言板，便于学习的源码

用JAVA写的留言板原代码

/*

* guestbookServlet.java

*

* */

import javax.servlet.*;

import javax.servlet.http.*;

import java.sql.*;

import java.util.Date;

/**

*

* */

public class guestbookServlet extends HttpServlet {

boolean debug=false;

String sDBDriver;

Connection conn=null;

ResultSet rs=null;

/** Initializes the servlet.

*/

public void init(ServletConfig config) throws ServletException {

super.init(config);

if(debug)

sDBDriver=new String("sun.jdbc.odbc.JdbcOdbcDriver");

else

sDBDriver=new String("org.gjt.mm.mysql.Driver");

try{

Class.forName(sDBDriver);

}

catch(java.lang.ClassNotFoundException e){

System.err.println("Driver类初始化:"+e.getMessage());

}

}

/** Destroys the servlet.

*/

public void destroy() {

}

/** Processes requests for both HTTP codeGET/code and codePOST/code methods.

* @param request servlet request

* @param response servlet response

*/

protected void processRequest(HttpServletRequest request, HttpServletResponse response)

throws ServletException, java.io.IOException {

response.setContentType("text/html;charset=gb2312");

java.io.PrintWriter out = response.getWriter();

boolean empty=true;

boolean noResult=true;

String sqlStr;

int currentPage=0;

int totalPage=0;

int reccount=0;

ResultSet myrs=null;

String username=request.getParameter("username");

String email=request.getParameter("email");

String ucontent=request.getParameter("ucontent");

String ipage=request.getParameter("ipage");

if(ipage==null||ipage.length()==0)

currentPage=1;

else

currentPage=Integer.parseInt(ipage);

if((username==null||username.length()==0)||(ucontent==null||ucontent.length()==0))empty=true;

else empty=false;

Date myDate=new Date();

//String intime=new String(String.valueOf(myDate.getYear()+1990)+String.valueOf(myDate.getMonth()));

String year=String.valueOf(myDate.getYear()+1900);

String month=String.valueOf(myDate.getMonth()+1);

if(month.length()==1)

month=new String("0"+month);

String days=String.valueOf(myDate.getDate());

if(days.length()==1)

days=new String("0"+days);

String hours=String.valueOf(myDate.getHours());

if(hours.length()==1)

hours=new String("0"+hours);

String minutes=String.valueOf(myDate.getMinutes());

if(minutes.length()==1)

minutes=new String("0"+minutes);

String intime=year+"-"+month+"-"+days+" "+hours+":"+minutes;

if(email==null||email.length()==0)

email=new String("");

if(!empty){

//username=convert(username);

//email=convert(email);

//ucontent=convert(ucontent);

sqlStr="insert into Mintegbook(Mname,Memail,Mcontent,Mtime,Mid) values("+username+","+email+","+ucontent+","+intime+",1)";

getDsnConn();

executeInsert(sqlStr);

}

sqlStr=new String("select Mname,Memail,Mcontent,Mtime from Mintegbook order by Mtime DESC");

getDsnConn();

reccount=getRecordCount("Mintegbook");

if(reccount==0)

noResult=true;

else

noResult=false;

if(!noResult){

int ipageSize=10;

totalPage=getTotalPage("Mintegbook",ipageSize);

if(currentPagetotalPage)

currentPage=totalPage;

int cursor=(currentPage-1)*ipageSize+1;

try{

myrs=executeScrollableQuery(sqlStr);

myrs.absolute(cursor);

}

catch(SQLException e){

noResult=true;

}

}

out.println("HTMLHEADTITLE我的Servlet留言板/TITLE");

out.println("META http-equiv="Content-Type" content="text/html; charset=gb2312"");

out.println("STYLE type="text/css"");

out.println("!--");

out.println(".mytext { font-family: "宋体"; font-size: 12px}");

out.println(" --");

out.println("/STYLE");

out.println("/HEAD");

out.println("BODY bgcolor="#FFFFFF" text="#000000"");

out.println("TABLE width="600" border="0" cellspacing="0" cellpadding="0" align="CENTER" class="mytext"");

out.println("TRTD height="22" | a href=""我的主页/a | 我的Servlet留言板(A href="mailto:yf188@21cn.com"川石/A制作)/TD/TR");

out.println("TRTD height="1" bgcolor="#999933"/TD/TR");

out.println("/TABLE");

out.println("BR");

out.println("TABLE width="600" border="0" cellspacing="0" cellpadding="0" align="CENTER" class="mytext"");

out.println("TRTD height="8"/TD/TR");

out.println("TRTD height="18" bgcolor="#f7f7f7"DIV align="right"");

out.println("共有 "+reccount + " 条留言 ");

out.println(" 当前第font color=#ff0000"+currentPage+"/font/共 "+totalPage+" 页 ");

if(currentPage1)

out.println(" a href=guestbookServlet?ipage=1首页/a a href=guestbookServlet?ipage="+(currentPage-1)+"上一页/a ");

else

out.println(" 首页 上一页 ");

if(currentPagetotalPage)

out.println(" a href=guestbookServlet?ipage="+(currentPage+1)+"下一页/a a href=guestbookServlet?ipage="+totalPage+"末页/a ");

else

out.println(" 下一页 末页 ");

out.println("/DIV/TD/TR");

out.println("/TABLE");

out.println("BR");

//这里是显示留言内容

if(!noResult){

String dname;

String demail;

String dcontent;

String dtime;

Date temptime;

try{

do{

dname=new String(myrs.getString("Mname"));

demail=new String(myrs.getString("Memail"));

dcontent=new String(myrs.getString("Mcontent"));

try{

dtime=new String(myrs.getObject("Mtime").toString());

}

catch(java.lang.NullPointerException e){

dtime=new String("2001-04-06 12:30");

}

if(dname==null)

dname=new String("川石");

if(demail==null)

demail=new String("yf188@21cn.com");

if(dcontent==null)

dcontent=new String("test");

if(dtime==null)

dtime=new String("2001-04-06 12:30");

dname=convert(dname);

dcontent=convert(dcontent);

//temptime=myrs.getDate("Mtime");

/*

String tempyear=String.valueOf(temptime.getYear()+1900);

String tempmonth=String.valueOf(temptime.getMonth()+1);

if(tempmonth.length()==1)

tempmonth=new String("0"+tempmonth);

String tempdays=String.valueOf(temptime.getDate());

if(tempdays.length()==1)

tempdays=new String("0"+tempdays);

String tempminute=String.valueOf(temptime.getMinutes());

if(tempminute.length()==1)

tempminute=new String("0"+tempminute);

String temphours=String.valueOf(temptime.getHours());

if(temphours.length()==1)

temphours=new String("0"+temphours);

String dtime=tempyear+" 年 "+ tempmonth +" 月 "+ tempdays +" 日 " + temphours+ " 时 "+ tempminute + " 分 ";

*/

out.println("TABLE width="600" border="0" cellspacing="0" cellpadding="4" align="CENTER" class="mytext"");

out.println("TRTD姓名 A href="mailto:"+demail+"""+dname+"/A 留言时间："+dtime+"/TD/TR");

out.println("TRTD height="10"/TD/TR");

out.println("TRTD height="10""+dcontent+"/TD/TR");

out.println("/TABLE");

out.println("HR width="600" size="1"");

}while(myrs.next());}

catch(SQLException e){

out.println("error found");

}

}

else{

out.println("还没有留言！");

}

//结束

out.println("FORM name="form1" method="post" action="guestbookServlet"");

out.println("TABLE width="600" border="0" cellspacing="0" cellpadding="4" align="CENTER" class="mytext"");

out.println("TRTD width="80"姓名:/TDTDINPUT type="text" name="username"*/TD/TR");

out.println("TRTDEmail:/TDTDINPUT type="text" name="email"*/TD/TR");

out.println("TRTD留言：/TDTDTEXTAREA name="ucontent" cols="65" rows="4"/TEXTAREA/TD/TR");

out.println("/TABLE");

out.println("TABLE width="400" border="0" cellspacing="0" cellpadding="6" align="CENTER" class="mytext"");

out.println("TRTD height="15" width="200" /TDTD /TD/TR");

out.println("TRTDDIV align="RIGHT"INPUT type="button" name="Button" value=" 提 交 " style="cursor:hand" onclick="javascript:check()"/DIV/TD");

out.println("TDINPUT type="reset" name="Submit2" value=" 重 置 "/TD/TR");

out.println("/TABLE");

out.println("/FORM");

out.println("TABLE width="400" border="0" cellspacing="0" cellpadding="4" align="CENTER" class="mytext"");

out.println("TRTD width="15" /TD/TR");

out.println("TRTDDIV align="LEFT"/DIV/TD/TR");

out.println("TRTD /TD/TR");

out.println("/TABLE");

out.println("/BODY");

out.println("/HTML");

out.println("SCRIPT language="javascript"");

out.println("function check(){");

out.println("if(form1.username.value.length1||form1.ucontent.value.length1)");

out.println("{alert(姓名和留言是必须有的!);}else{form1.submit();}}");

out.println("/SCRIPT");

out.close();

}

/** Handles the HTTP codeGET/code method.

* @param request servlet request

* @param response servlet response

*/

protected void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, java.io.IOException {

processRequest(request, response);

}

/** Handles the HTTP codePOST/code method.

* @param request servlet request

* @param response servlet response

*/

protected void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, java.io.IOException {

processRequest(request, response);

}

protected void getDsnConn(){

String sqlUrl="jdbc:mysql://10.0.0.1/你申请用户名?user=你的名字password=你的帐号";

try{

if(debug)

conn=DriverManager.getConnection("jdbc:odbc:ODBC源","用户名","密码口令");

else

conn=DriverManager.getConnection(sqlUrl);

}

catch(SQLException es){

System.err.println("和库连接时出错:"+es.getMessage());

}

}

protected void executeInsert(String sqlStr){

try{

Statement stmt=conn.createStatement();

stmt.executeUpdate(sqlStr);

}

catch(SQLException es){

System.err.println("执行插入时:"+es.getMessage());

}

}

protected void executeUpdate(String sqlStr){

try{

Statement stmt=conn.createStatement();

stmt.executeUpdate(sqlStr);

}

catch(SQLException e){

System.err.println("error in query record");

}

}

//查寻

protected ResultSet executeQuery(String sqlStr){

rs=null;

try{

Statement stmt=conn.createStatement();

rs=stmt.executeQuery(sqlStr);

}

catch(SQLException ex){

System.err.println("执行查寻出错："+ex.getMessage());

}

return rs;

}

protected ResultSet executeScrollableQuery(String sqlStr){

rs=null;

try{

Statement stmt=conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);

rs=stmt.executeQuery(sqlStr);

}

catch(SQLException e){

System.err.println("执行动态查寻出错");

}

return rs;

}

//得到表记录总数

protected int getRecordCount(String sTableName){

rs=null;

int CountResult=0;

String sqlStr="select count(*) from "+sTableName;

try{

Statement stmt=conn.createStatement();

rs=stmt.executeQuery(sqlStr);

if(rs.next())

CountResult=rs.getInt(1);

rs=null;

stmt.close();

}

catch(SQLException ex){

System.err.println(ex.getMessage());

}

return CountResult;

}

//得到记录总页数

protected int getTotalPage(String sTableName,int iPageSize){

int totalPage;

int totalRecNum=getRecordCount(sTableName);

if(totalRecNum%iPageSize==0)

totalPage=totalRecNum/iPageSize;

else

totalPage=totalRecNum/iPageSize+1;

return totalPage;

}

protected String convert(String InputStr){

String converted=new String();

byte[] bytes;

try{

bytes=InputStr.getBytes("ISO8859-1");

converted=new String(bytes,"GB2312");

}

catch(java.io.UnsupportedEncodingException e){

System.out.print("error");

}

return converted;

}

/** Returns a short description of the servlet.

*/

public String getServletInfo() {

return "Short description";

}

}

求编写一个超级简单的Java的程序源代码

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

class ConstructFrame extends JFrame

{

private static final long serialVersionUID = 1L;

String value1="",result,value2="";

int flag=0,fix=0,sum=1;

Boolean happy;

JTextField text=new JTextField(30);

int flagsum=0;

Container c=getContentPane();

JButton buttonx;

ConstructFrame()

{ super("计算器");

c.setLayout(null);

c.setBackground(Color.blue);

this.setSize(400, 400);

c.add(text);

text.setHorizontalAlignment(JTextField.RIGHT);

final JButton buttonx=new JButton("BackSpace");

c.add(buttonx);

buttonx.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

int count=0;

String temp;

if(flag==0)

{

count=value1.length();

if(count!=1)

temp=value1.substring(0, count-1);

else

temp="0";

value1=temp;

}

else

{

count=value2.length();

if(count!=1)

temp=value2.substring(0, count-1);

else

temp="0";

value2=temp;

}

text.setText(temp);

}

});

final JButton buttony=new JButton("CE");

c.add(buttony);

buttony.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

value1="";

value2="";

flag=0;

text.setText("0");

}

});

final JButton button1=new JButton("1");

c.add(button1);

button1.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

String temp;

if(flag==0)

{

value1=value1+1;

temp=value1;

}

else

{

value2=value2+1;

temp=value2;

}

text.setText(temp);

}

});

final JButton button2=new JButton(" 2 ");

c.add(button2);

button2.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

String temp;

if(flag==0)

{

value1=value1+2;

temp=value1;

}

else

{

value2=value2+2;

temp=value2;

}

text.setText(temp);

}

});

final JButton button3=new JButton("3");

c.add(button3);

button3.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

String temp;

if(flag==0)

{

value1=value1+3;

temp=value1;

}

else

{

value2=value2+3;

temp=value2;

}

text.setText(temp);

}

});

final JButton button4=new JButton("4");

c.add(button4);

button4.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

String temp;

if(flag==0)

{

value1=value1+4;

temp=value1;

}

else

{

value2=value2+4;

temp=value2;

}

text.setText(temp);

}

});

final JButton button5=new JButton("5");

c.add(button5);

button5.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

String temp;

if(flag==0)

{

value1=value1+5;

temp=value1;

}

else

{

value2=value2+5;

temp=value2;

}

text.setText(temp);

}

});

final JButton button6=new JButton("6");

c.add(button6);

button6.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

String temp;

if(flag==0)

{

value1=value1+6;

temp=value1;

}

else

{

value2=value2+6;

temp=value2;

}

text.setText(temp);

}

});

final JButton button7=new JButton("7");

c.add(button7);

button7.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

String temp;

if(flag==0)

{

value1=value1+7;

temp=value1;

}

else

{

value2=value2+7;

temp=value2;

}

text.setText(temp);

}

});

final JButton button8=new JButton("8");

c.add(button8);

button8.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

String temp;

if(flag==0)

{

value1=value1+8;

temp=value1;

}

else

{

value2=value2+8;

temp=value2;

}

text.setText(temp);

}

});

final JButton button9=new JButton("9");

c.add(button9);

button9.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

String temp;

if(flag==0)

{

value1=value1+9;

temp=value1;

}

else

{

value2=value2+9;

temp=value2;

}

text.setText(temp);

}

});

final JButton button0=new JButton("0");

c.add(button0);

button0.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

String temp;

if(flag==0)

{

value1=value1+0;

temp=value1;

}

else

{

value2=value2+0;

temp=value2;

}

text.setText(temp);

}

});

final JButton buttonadd=new JButton(" + ");

c.add(buttonadd);

buttonadd.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

flag=1;

fix=1;

flagsum=0;

}

});

final JButton buttonsubtract=new JButton(" - ");

c.add(buttonsubtract);

buttonsubtract.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

flag=1;

fix=2;

flagsum=0;

}

});

final JButton buttoncheng=new JButton(" * ");

c.add(buttoncheng);

buttoncheng.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

flag=1;

fix=3;

flagsum=0;

}

});

final JButton buttonchu=new JButton(" / ");

c.add(buttonchu);

buttonchu.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

flag=1;

flagsum=0;

fix=4;

}

});

final JButton buttonequal=new JButton(" = ");

c.add(buttonequal);

buttonequal.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

double temp1,temp2;

double temp=0;

flagsum=0;

temp1=Double.parseDouble(value1);

temp2=Double.parseDouble(value2);

flag=0;

switch(fix)

{

case 1: temp=temp1+temp2;break;

case 2: temp=temp1-temp2;break;

case 3: temp=temp1*temp2;break;

case 4: temp=temp1/temp2;break;

}

result=Double.valueOf(temp).toString();

value1=result;

value2="";

flag=1;

text.setText(result);

}

});

final JButton buttonpoint=new JButton(".");

c.add(buttonpoint);

buttonpoint.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{ if(flagsum==0)

{

String temp;

if(flag==0 )

{

value1=value1+".";

temp=value1;

}

else

{

value2=value2+".";

temp=value2;

}

flagsum=1;

text.setText(temp);

}

}

});

JButton buttonz=new JButton("Start");

c.add(buttonz);

buttonz.addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{ if(sum%2==1)

{

happy=true;

text.setText("0.");

flag=0;

}

else

{

happy=false;

value1="";

value2="";

text.setText("");

}

text.setEnabled(happy);

button1.setEnabled(happy);

button2.setEnabled(happy);

button3.setEnabled(happy);

button4.setEnabled(happy);

button5.setEnabled(happy);

button6.setEnabled(happy);

button7.setEnabled(happy);

button8.setEnabled(happy);

button9.setEnabled(happy);

button0.setEnabled(happy);

buttonx.setEnabled(happy);

buttony.setEnabled(happy);

buttonadd.setEnabled(happy);

buttonsubtract.setEnabled(happy);

buttonpoint.setEnabled(happy);

buttonequal.setEnabled(happy);

buttoncheng.setEnabled(happy);

buttonchu.setEnabled(happy);

sum++;

}

});

button1.setEnabled(false);

button2.setEnabled(false);

button3.setEnabled(false);

button4.setEnabled(false);

button5.setEnabled(false);

button6.setEnabled(false);

button7.setEnabled(false);

button8.setEnabled(false);

button9.setEnabled(false);

button0.setEnabled(false);

buttonx.setEnabled(false);

buttony.setEnabled(false);

buttonadd.setEnabled(false);

buttonsubtract.setEnabled(false);

buttonpoint.setEnabled(false);

buttonequal.setEnabled(false);

buttoncheng.setEnabled(false);

buttonchu.setEnabled(false);

text.setEnabled(false);

text.setBounds(20, 20, 200, 40);

buttonx.setBounds(20, 60,100, 40);

buttony.setBounds(140, 60,100, 40);

buttonz.setBounds(260, 60,80, 40);

button1.setBounds(20, 120,60, 40);

button2.setBounds(100, 120,60, 40);

button3.setBounds(180, 120,60, 40);

buttonadd.setBounds(260, 120,60, 40);

button4.setBounds(20, 180,60, 40);

button5.setBounds(100, 180,60, 40);

button6.setBounds(180, 180,60, 40);

buttonsubtract.setBounds(260, 180,60, 40);

button7.setBounds(20, 240,60, 40);

button8.setBounds(100, 240,60, 40);

button9.setBounds(180, 240,60, 40);

buttoncheng.setBounds(260,240,60,40);

button0.setBounds(20, 300,60, 40);

buttonpoint.setBounds(100, 300, 60, 40);

buttonequal.setBounds(180,300,60, 40);

buttonchu.setBounds(260, 300,60, 40);

setVisible(true);

}

class MYMouseEvent extends MouseAdapter

{

public void mousePressed(MouseEvent e)

{

value1=e.toString();

text.setText(value1);

}

}

}

class Calutator

{

public static void main(String[] args)

{

new ConstructFrame();

}

}

你自己慢慢的看吧！

急急急！java简单留言板

您好。我重新地帮你写了代码，完全地符合了你的图片中的界面要求、功能要求。代码如下：（解决了问题，记得给我分哦~^_^呵呵……）

import java.awt.BorderLayout;

import javax.swing.JPanel;

import javax.swing.JFrame;

import java.awt.Rectangle;

import javax.swing.JLabel;

import javax.swing.SwingConstants;

import java.awt.Font;

import javax.swing.JTextArea;

import javax.swing.JScrollBar;

import javax.swing.JScrollPane;

import javax.swing.JComboBox;

import javax.swing.JTextField;

import javax.swing.JButton;

public class Liuyb extends JFrame {

private static final long serialVersionUID = 1L;

private JPanel jContentPane = null;

private JLabel jLabel = null;

private JTextArea jTextArea = null;

private JScrollPane jScrollPane = null;

private JLabel jLabel1 = null;

private JComboBox jComboBox = null;

private JLabel jLabel2 = null;

private JTextField jTextField = null;

private JButton jButton = null;

private JButton jButton1 = null;

private JButton jButton2 = null;

private JButton jButton3 = null;

/**

* This is the default constructor

*/

public Liuyb() {

super();

initialize();

}

/**

* This method initializes this

*

* @return void

*/

private void initialize() {

this.setContentPane(getJContentPane());

this.setTitle("留言板程序");

this.setBounds(new Rectangle(0, 0, 640, 480));

this.setVisible(true);

}

/**

* This method initializes jContentPane

*

* @return javax.swing.JPanel

*/

private JPanel getJContentPane() {

if (jContentPane == null) {

jLabel2 = new JLabel();

jLabel2.setBounds(new Rectangle(214, 407, 45, 24));

jLabel2.setFont(new Font("Dialog", Font.BOLD, 14));

jLabel2.setText("地说：");

jLabel1 = new JLabel();

jLabel1.setBounds(new Rectangle(32, 407, 15, 24));

jLabel1.setFont(new Font("Dialog", Font.BOLD, 14));

jLabel1.setText("你");

jLabel = new JLabel();

jLabel.setBounds(new Rectangle(283, 15, 45, 20));

jLabel.setHorizontalAlignment(SwingConstants.CENTER);

jLabel.setFont(new Font("Dialog", Font.BOLD, 14));

jLabel.setText("留言板");

jContentPane = new JPanel();

jContentPane.setLayout(null);

jContentPane.add(jLabel, null);

jContentPane.add(getJScrollPane(), null);

jContentPane.add(jLabel1, null);

jContentPane.add(getJComboBox(), null);

jContentPane.add(jLabel2, null);

jContentPane.add(getJTextField(), null);

jContentPane.add(getJButton(), null);

jContentPane.add(getJButton1(), null);

jContentPane.add(getJButton2(), null);

jContentPane.add(getJButton3(), null);

}

return jContentPane;

}

/**

* This method initializes jTextArea

*

* @return javax.swing.JTextArea

*/

private JTextArea getJTextArea() {

if (jTextArea == null) {

jTextArea = new JTextArea();

jTextArea.setText("留言内容：");

jTextArea.setEditable(false);

}

return jTextArea;

}

/**

* This method initializes jScrollPane

*

* @return javax.swing.JScrollPane

*/

private JScrollPane getJScrollPane() {

if (jScrollPane == null) {

jScrollPane = new JScrollPane();

jScrollPane.setBounds(new Rectangle(22, 49, 534, 347));

jScrollPane.setViewportView(getJTextArea());

}

return jScrollPane;

}

/**

* This method initializes jComboBox

*

* @return javax.swing.JComboBox

*/

private JComboBox getJComboBox() {

if (jComboBox == null) {

jComboBox = new JComboBox();

jComboBox.setBounds(new Rectangle(54, 407, 149, 24));

String[] mycbox={"微笑","大笑","痛苦"};

jComboBox.addItem(mycbox[0]);

jComboBox.addItem(mycbox[1]);

jComboBox.addItem(mycbox[2]);

}

return jComboBox;

}

/**

* This method initializes jTextField

*

* @return javax.swing.JTextField

*/

private JTextField getJTextField() {

if (jTextField == null) {

jTextField = new JTextField();

jTextField.setBounds(new Rectangle(265, 407, 231, 24));

}

return jTextField;

}

/**

* This method initializes jButton

*

* @return javax.swing.JButton

*/

private JButton getJButton() {

if (jButton == null) {

jButton = new JButton();

jButton.setBounds(new Rectangle(505, 407, 70, 24));

jButton.setText("提交");

jButton.addActionListener(new java.awt.event.ActionListener() {

public void actionPerformed(java.awt.event.ActionEvent e) {

jTextArea.setText(jTextArea.getText()+"\r\n"+"你"+jComboBox.getSelectedItem().toString()+"地说："+jTextField.getText());

}

});

}

return jButton;

}

/**

* This method initializes jButton1

*

* @return javax.swing.JButton

*/

private JButton getJButton1() {

if (jButton1 == null) {

jButton1 = new JButton();

jButton1.setBounds(new Rectangle(565, 51, 60, 32));

jButton1.setText("清屏");

jButton1.addActionListener(new java.awt.event.ActionListener() {

public void actionPerformed(java.awt.event.ActionEvent e) {

jTextArea.setText("留言内容：");

}

});

}

return jButton1;

}

/**

* This method initializes jButton2

*

* @return javax.swing.JButton

*/

private JButton getJButton2() {

if (jButton2 == null) {

jButton2 = new JButton();

jButton2.setBounds(new Rectangle(565, 112, 60, 32));

jButton2.setText("置顶");

jButton2.addActionListener(new java.awt.event.ActionListener() {

public void actionPerformed(java.awt.event.ActionEvent e) {

jTextArea.setCaretPosition(0);

}

});

}

return jButton2;

}

/**

* This method initializes jButton3

*

* @return javax.swing.JButton

*/

private JButton getJButton3() {

if (jButton3 == null) {

jButton3 = new JButton();

jButton3.setBounds(new Rectangle(565, 173, 60, 32));

jButton3.setText("至尾");

jButton3.addActionListener(new java.awt.event.ActionListener() {

public void actionPerformed(java.awt.event.ActionEvent e) {

jTextArea.setCaretPosition((int)jTextArea.getText().length());

}

});

}

return jButton3;

}

public static void main(String args[]){

new Liuyb();

}

}

用Java web 做一个留言板 留言功能实现了，不知道怎么实现回复和删除留言的功能，知道的高手，请帮帮忙。

先说说回复吧：

假如:

留言表（id , text ）两个字段

回复表（ id , text parentId ）用来存放留言表id 三个字段

目前有一条留言

1001,'这是一条留言';

那么给这条留言的回复就是

1003 , '这是一条回复', 1001(这就是该留言的ID) 这样就把留言和回复关联上了

回复后点保存时，将数据传入后台，数据库做insert操作就行了

删除一样的

如果删除回复，直接传入回复的ID 即可

如果删除留言，得先判断该留言有没有回复，如果有回复，则先删除回复，在删除留言（外键约束）