Java里的字节码和源代码分别啥意思，和起到什么左右
/*java是一门高级编程语言，是用来写程序代码的。
目前创新互联已为近千家的企业提供了网站建设、域名、网页空间、网站托管运营、企业网站设计、达坂城网站维护等服务，公司将坚持客户导向、应用为本的策略，正道将秉承"和谐、参与、激情"的文化，与客户和合作伙伴齐心协力一起成长，共同发展。
用java写的文本（字符串序列）就是源代码。
计算机不能直接执行源代码，必须用一个叫编译器的程序（javac.exe）将源代码
翻译成字节码，然后让一个叫解释器的程序（java.exe）去执行字节码，即运行程序。
下面的就是一个小程序的源代码，功能是输出九九乘法表。
下图中的Test.class就是这个源代码文件翻译后的由字节码组成的文件。
而最下面的那个黑框就是程序执行后的结果。
java Test就是在执行Test.class字节码文件，即运行这个程序。
*/
//这下面的就是源代码
public class Test {
public static void main(String[] args) {
int i,j;
for(i=1;i=9;i++) {
for(j=1;j=i;j++)
System.out.printf("%dx%d=%-4d",j,i,j*i);
System.out.println();
}
}
}
java简单记事本源代码 带解释
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
class test implements ActionListener
{
JFrame frame;
JButton b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,b17,b18,b19,b20,b21,b22,b23,b24,b25,b26,b27,b28,b29,b30,b31;
JTextArea ta;
JPanel p1,p2,p3,p4;
JMenuBar mb;
JMenu m1,m2,m3;
JMenuItem mt1,mt2,mt3,mt4,mt5,mt6,mt7;
JRadioButton rb1,rb2;
ButtonGroup bg;
Double d1=0.0,d2=0.0,d3=0.0,d4=1.0,d5=1.0;
String s1="",s2="",s3="",s4="";
int a=0;
char c1;
int i=0;
public static void main(String[] args)
{
test that=new test();
that.go();
}
public void go()
{
frame=new JFrame("计算器");
Container cp= frame.getContentPane();
cp.setLayout(new FlowLayout());
b1=new JButton("7");b2=new JButton("8");b3=new JButton("9");b4=new JButton("/");b5=new JButton("1/x");b6=new JButton("sin");b7=new JButton("log");
b8=new JButton("4");b9=new JButton("5");b10=new JButton("6");b11=new JButton("*");b12=new JButton("x^y");b13=new JButton("cos");b14=new JButton("ln");
b15=new JButton("1");b16=new JButton("2");b17=new JButton("3");b18=new JButton("-");b19=new JButton(new ImageIcon("lanying.gif"));b20=new JButton("tan");b21=new JButton("x^3");
b22=new JButton("0");b23=new JButton("+/-");b24=new JButton(".");b25=new JButton("+");b26=new JButton("√x");b27=new JButton("cot");b28=new JButton("x^2");
b29=new JButton("Backspace");b30=new JButton("C");b31=new JButton("=");
mb=new JMenuBar();
m1=new JMenu("文件(F)");m2=new JMenu("编辑(E)");m3=new JMenu("帮助(H)");
mt1=new JMenuItem("清零");mt2=new JMenuItem("退出");mt3=new JMenuItem("复制");mt4=new JMenuItem("粘贴");mt5=new JMenuItem("版本");mt6=new JMenuItem("标准型");mt7=new JMenuItem("科学型");
ta=new JTextArea(1,30);
p1=new JPanel();p2=new JPanel();p3=new JPanel();p4=new JPanel();
rb1=new JRadioButton("科学型");rb2=new JRadioButton("标准型");
bg=new ButtonGroup();
b1.setForeground(Color.blue);b1.setBackground(Color.white);b2.setForeground(Color.blue);b2.setBackground(Color.white);
b3.setForeground(Color.blue);b3.setBackground(Color.white);b8.setForeground(Color.blue);b8.setBackground(Color.white);
b9.setForeground(Color.blue);b9.setBackground(Color.white);b10.setForeground(Color.blue);b10.setBackground(Color.white);
b15.setForeground(Color.blue);b15.setBackground(Color.white);b16.setForeground(Color.blue);b16.setBackground(Color.white);
b17.setForeground(Color.blue);b17.setBackground(Color.white);b22.setForeground(Color.blue);b22.setBackground(Color.white);
b23.setForeground(Color.blue);b23.setBackground(Color.white);b24.setForeground(Color.blue);b24.setBackground(Color.white);
b4.setForeground(Color.red);b4.setBackground(Color.white);b11.setForeground(Color.red);b11.setBackground(Color.white);
b18.setForeground(Color.red);b18.setBackground(Color.white);b25.setForeground(Color.red);b25.setBackground(Color.white);
b5.setForeground(Color.blue);b5.setBackground(Color.white);b6.setForeground(Color.blue);b6.setBackground(Color.white);
b7.setForeground(Color.blue);b7.setBackground(Color.white);b12.setForeground(Color.blue);b12.setBackground(Color.white);
b13.setForeground(Color.blue);b13.setBackground(Color.white);b14.setForeground(Color.blue);b14.setBackground(Color.white);
b19.setForeground(Color.blue);b19.setBackground(Color.white);b20.setForeground(Color.blue);b20.setBackground(Color.white);
b21.setForeground(Color.blue);b21.setBackground(Color.white);b26.setForeground(Color.blue);b26.setBackground(Color.white);
b27.setForeground(Color.blue);b27.setBackground(Color.white);b28.setForeground(Color.blue);b28.setBackground(Color.white);
b29.setForeground(Color.red);b29.setBackground(Color.white);b30.setForeground(Color.red);b30.setBackground(Color.white);
b31.setForeground(Color.red);b31.setBackground(Color.white);
bg.add(rb1);bg.add(rb2);
p1.setBackground(Color.yellow);
cp.setBackground(Color.CYAN);
m1.setMnemonic(KeyEvent.VK_F);m2.setMnemonic(KeyEvent.VK_E);m3.setMnemonic(KeyEvent.VK_H);
m1.add(mt6);m1.add(mt7);m1.addSeparator();m1.add(mt1);m1.addSeparator();m1.add(mt2);m2.add(mt3);m2.addSeparator();m2.add(mt4);m3.add(mt5);
mb.add(m1);mb.add(m2);mb.add(m3);
frame.setJMenuBar(mb);
p2.setLayout(new GridLayout(4,7));
p3.setLayout(new GridLayout(1,3));
ta.setEditable(false);
p1.add(ta);
p2.add(b1);p2.add(b2);p2.add(b3);p2.add(b4);p2.add(b5);p2.add(b6);p2.add(b7);
p2.add(b8);p2.add(b9);p2.add(b10);p2.add(b11);p2.add(b12);p2.add(b13);p2.add(b14);
p2.add(b15);p2.add(b16);p2.add(b17);p2.add(b18);p2.add(b19);p2.add(b20);p2.add(b21);
p2.add(b22);p2.add(b23);p2.add(b24);p2.add(b25);p2.add(b26);p2.add(b27);p2.add(b28);
p3.add(b29);p3.add(b30);p3.add(b31);
Border etched=BorderFactory.createEtchedBorder();
Border border=BorderFactory.createTitledBorder(etched,"计算类型");
p4.add(rb1);p4.add(rb2);
p4.setBorder(border);
b2.setActionCommand("8");
b2.addActionListener(this);
cp.add(p1);cp.add(p4);cp.add(p2);cp.add(p3);
frame.setSize(400,330);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
b1.setActionCommand("7");
b1.addActionListener(this);
b2.setActionCommand("8");
b2.addActionListener(this);
b3.setActionCommand("9");
b3.addActionListener(this);
b4.setActionCommand("/");
b4.addActionListener(this);
b5.setActionCommand("1/x");
b5.addActionListener(this);
b6.setActionCommand("sin");
b6.addActionListener(this);
b7.setActionCommand("log");
b7.addActionListener(this);
b8.setActionCommand("4");
b8.addActionListener(this);
b9.setActionCommand("5");
b9.addActionListener(this);
b10.setActionCommand("6");
b10.addActionListener(this);
b11.setActionCommand("*");
b11.addActionListener(this);
b12.setActionCommand("x^y");
b12.addActionListener(this);
b13.setActionCommand("cos");
b13.addActionListener(this);
b14.setActionCommand("ln");
b14.addActionListener(this);
b15.setActionCommand("1");
b15.addActionListener(this);
b16.setActionCommand("2");
b16.addActionListener(this);
b17.setActionCommand("3");
b17.addActionListener(this);
b18.setActionCommand("-");
b18.addActionListener(this);
b19.setActionCommand("x!");
b19.addActionListener(this);
b20.setActionCommand("tan");
b20.addActionListener(this);
b21.setActionCommand("x^3");
b21.addActionListener(this);
b22.setActionCommand("0");
b22.addActionListener(this);
b23.setActionCommand("+/-");
b23.addActionListener(this);
b24.setActionCommand(".");
b24.addActionListener(this);
b25.setActionCommand("+");
b25.addActionListener(this);
b26.setActionCommand("√x");
b26.addActionListener(this);
b27.setActionCommand("cot");
b27.addActionListener(this);
b28.setActionCommand("x^2");
b28.addActionListener(this);
b29.setActionCommand("Backspace");
b29.addActionListener(this);
b30.setActionCommand("C");
b30.addActionListener(this);
b31.setActionCommand("=");
b31.addActionListener(this);
rb1.setActionCommand("kxx");
rb1.addActionListener(this);
rb2.setActionCommand("bzx");
rb2.addActionListener(this);
}
public void actionPerformed(ActionEvent e) //throws Exception
{
if (e.getActionCommand()=="bzx")
{
b5.setEnabled(false);b6.setEnabled(false);b7.setEnabled(false);
b12.setEnabled(false);b13.setEnabled(false);b14.setEnabled(false);
b19.setEnabled(false);b20.setEnabled(false);b21.setEnabled(false);
b26.setEnabled(false);b27.setEnabled(false);b28.setEnabled(false);
}
if (e.getActionCommand()=="kxx")
{
b5.setEnabled(true);b6.setEnabled(true);b7.setEnabled(true);
b12.setEnabled(true);b13.setEnabled(true);b14.setEnabled(true);
b19.setEnabled(true);b20.setEnabled(true);b21.setEnabled(true);
b26.setEnabled(true);b27.setEnabled(true);b28.setEnabled(true);
}
if (e.getActionCommand()=="1")
{
ta.append("1");
}
if (e.getActionCommand()=="2")
{
ta.append("2");
}
if (e.getActionCommand()=="3")
{
ta.append("3");
}
if (e.getActionCommand()=="4")
{
ta.append("4");
}
if (e.getActionCommand()=="5")
{
ta.append("5");
}
if (e.getActionCommand()=="6")
{
ta.append("6");
}
if (e.getActionCommand()=="7")
{
ta.append("7");
}
if (e.getActionCommand()=="8")
{
ta.append("8");
}
if (e.getActionCommand()=="9")
{
ta.append("9");
}
if (e.getActionCommand()=="0")
{
ta.append("0");
}
if (e.getActionCommand()=="+")
{
s1=ta.getText();
d1 = Double.parseDouble(s1);
ta.setText("");
i=1;
}
if (e.getActionCommand()=="-")
{
s1=ta.getText();
d1 = Double.parseDouble(s1);
ta.setText("");
i=2;
}
if (e.getActionCommand()=="*")
{
s1=ta.getText();
d1 = Double.parseDouble(s1);
ta.setText("");
i=3;
}
if (e.getActionCommand()=="/")
{
s1=ta.getText();
d1 = Double.parseDouble(s1);
ta.setText("");
i=4;
}
if (e.getActionCommand()=="=")
{
s2=ta.getText();
d2=Double.parseDouble(s2);
if(i==1)
{
d3=d1+d2;
ta.setText( d3.toString());
}
if(i==2)
{
d3=d1-d2;
ta.setText( d3.toString());
}
if(i==3)
{
d3=d1*d2;
ta.setText( d3.toString());
}
if(i==4)
{
if(d2==0.0)
ta.setText("ERROR");
else
{
d3=d1/d2;
ta.setText( d3.toString());
}
}
if (i==5)
{
s2=ta.getText();
d2 = Double.parseDouble(s2);
for (int l=1;l=d2 ; l++)
{
d5=d5*d1;
}
ta.setText( d5.toString());
}
}
if (e.getActionCommand()=="C")
{
ta.setText("");
d4=1.0;
d5=1.0;
}
/*if (e.getActionCommand()=="Backspace")
{
s3=ta.getText();
a=s3.length();
//ta.cut(ta.select(a-1,a));
s4=ta.getText(1,3);
ta.setText(s4);
}
*/
if (e.getActionCommand()=="1/x")
{
s1=ta.getText();
d1 = Double.parseDouble(s1);
d2=1/d1;
ta.setText( d2.toString());
}
if (e.getActionCommand()==".")
{
ta.append(".");
}
if (e.getActionCommand()=="+/-")
{
s1=ta.getText();
d1 = Double.parseDouble(s1);
d2=0-d1;
ta.setText( d2.toString());
}
if (e.getActionCommand()=="x^2")
{
s1=ta.getText();
d1 = Double.parseDouble(s1);
d2=d1*d1;
ta.setText( d2.toString());
}
if (e.getActionCommand()=="x^3")
{
s1=ta.getText();
d1 = Double.parseDouble(s1);
d2=d1*d1*d1;
ta.setText( d2.toString());
}
if (e.getActionCommand()=="x^y")
{
s1=ta.getText();
d1 = Double.parseDouble(s1);
ta.setText("");
i=5;
// d2=d1*d1*d1;
// ta.setText( d2.toString());
}
if (e.getActionCommand()=="√x")
{
s1=ta.getText();
d1 = Double.parseDouble(s1);
d2=Math.sqrt(d1);
ta.setText( d2.toString());
}
if (e.getActionCommand()=="x!")
{
s1=ta.getText();
d1 = Double.parseDouble(s1);
if (d10)
{
ta.setText( "error");
}
else if (d1==0)
{
ta.setText( "0.0");
}
else {
for (int k=1;k=d1 ;k++ )
d4=d4*k;
ta.setText( d4.toString());
}
}
if (e.getActionCommand()=="sin")
{
s1=ta.getText();
d1 = Double.parseDouble(s1);
d2=Math.sin(3.1415926*d1/180);
ta.setText( d2.toString());
}
}
}
跪地求好玩的JAVA 源代码~
连连看java源代码
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class lianliankan implements ActionListener
{
JFrame mainFrame; //主面板
Container thisContainer;
JPanel centerPanel,southPanel,northPanel; //子面板
JButton diamondsButton[][] = new JButton[6][5];//游戏按钮数组
JButton exitButton,resetButton,newlyButton; //退出，重列，重新开始按钮
JLabel fractionLable=new JLabel("0"); //分数标签
JButton firstButton,secondButton; //分别记录两次被选中的按钮
int grid[][] = new int[8][7];//储存游戏按钮位置
static boolean pressInformation=false; //判断是否有按钮被选中
int x0=0,y0=0,x=0,y=0,fristMsg=0,secondMsg=0,validateLV; //游戏按钮的位置坐标
int i,j,k,n;//消除方法控制
public void init(){
mainFrame=new JFrame("JKJ连连看");
thisContainer = mainFrame.getContentPane();
thisContainer.setLayout(new BorderLayout());
centerPanel=new JPanel();
southPanel=new JPanel();
northPanel=new JPanel();
thisContainer.add(centerPanel,"Center");
thisContainer.add(southPanel,"South");
thisContainer.add(northPanel,"North");
centerPanel.setLayout(new GridLayout(6,5));
for(int cols = 0;cols 6;cols++){
for(int rows = 0;rows 5;rows++ ){
diamondsButton[cols][rows]=new JButton(String.valueOf(grid[cols+1][rows+1]));
diamondsButton[cols][rows].addActionListener(this);
centerPanel.add(diamondsButton[cols][rows]);
}
}
exitButton=new JButton("退出");
exitButton.addActionListener(this);
resetButton=new JButton("重列");
resetButton.addActionListener(this);
newlyButton=new JButton("再来一局");
newlyButton.addActionListener(this);
southPanel.add(exitButton);
southPanel.add(resetButton);
southPanel.add(newlyButton);
fractionLable.setText(String.valueOf(Integer.parseInt(fractionLable.getText())));
northPanel.add(fractionLable);
mainFrame.setBounds(280,100,500,450);
mainFrame.setVisible(true);
}
public void randomBuild() {
int randoms,cols,rows;
for(int twins=1;twins=15;twins++) {
randoms=(int)(Math.random()*25+1);
for(int alike=1;alike=2;alike++) {
cols=(int)(Math.random()*6+1);
rows=(int)(Math.random()*5+1);
while(grid[cols][rows]!=0) {
cols=(int)(Math.random()*6+1);
rows=(int)(Math.random()*5+1);
}
this.grid[cols][rows]=randoms;
}
}
}
public void fraction(){
fractionLable.setText(String.valueOf(Integer.parseInt(fractionLable.getText())+100));
}
public void reload() {
int save[] = new int[30];
int n=0,cols,rows;
int grid[][]= new int[8][7];
for(int i=0;i=6;i++) {
for(int j=0;j=5;j++) {
if(this.grid[i][j]!=0) {
save[n]=this.grid[i][j];
n++;
}
}
}
n=n-1;
this.grid=grid;
while(n=0) {
cols=(int)(Math.random()*6+1);
rows=(int)(Math.random()*5+1);
while(grid[cols][rows]!=0) {
cols=(int)(Math.random()*6+1);
rows=(int)(Math.random()*5+1);
}
this.grid[cols][rows]=save[n];
n--;
}
mainFrame.setVisible(false);
pressInformation=false; //这里一定要将按钮点击信息归为初始
init();
for(int i = 0;i 6;i++){
for(int j = 0;j 5;j++ ){
if(grid[i+1][j+1]==0)
diamondsButton[i][j].setVisible(false);
}
}
}
public void estimateEven(int placeX,int placeY,JButton bz) {
if(pressInformation==false) {
x=placeX;
y=placeY;
secondMsg=grid[x][y];
secondButton=bz;
pressInformation=true;
}
else {
x0=x;
y0=y;
fristMsg=secondMsg;
firstButton=secondButton;
x=placeX;
y=placeY;
secondMsg=grid[x][y];
secondButton=bz;
if(fristMsg==secondMsg secondButton!=firstButton){
xiao();
}
}
}
public void xiao() { //相同的情况下能不能消去。仔细分析，不一条条注释
if((x0==x (y0==y+1||y0==y-1)) || ((x0==x+1||x0==x-1)(y0==y))){ //判断是否相邻
remove();
}
else{
for (j=0;j7;j++ ) {
if (grid[x0][j]==0){ //判断第一个按钮同行哪个按钮为空
if (yj) { //如果第二个按钮的Y坐标大于空按钮的Y坐标说明第一按钮在第二按钮左边
for (i=y-1;i=j;i-- ){ //判断第二按钮左侧直到第一按钮中间有没有按钮
if (grid[x][i]!=0) {
k=0;
break;
}
else{ k=1; } //K=1说明通过了第一次验证
}
if (k==1) {
linePassOne();
}
}
if (yj){ //如果第二个按钮的Y坐标小于空按钮的Y坐标说明第一按钮在第二按钮右边
for (i=y+1;i=j ;i++ ){ //判断第二按钮左侧直到第一按钮中间有没有按钮
if (grid[x][i]!=0){
k=0;
break;
}
else { k=1; }
}
if (k==1){
linePassOne();
}
}
if (y==j ) {
linePassOne();
}
}
if (k==2) {
if (x0==x) {
remove();
}
if (x0x) {
for (n=x0;n=x-1;n++ ) {
if (grid[n][j]!=0) {
k=0;
break;
}
if(grid[n][j]==0 n==x-1) {
remove();
}
}
}
if (x0x) {
for (n=x0;n=x+1 ;n-- ) {
if (grid[n][j]!=0) {
k=0;
break;
}
if(grid[n][j]==0 n==x+1) {
remove();
}
}
}
}
}
for (i=0;i8;i++ ) { //列
if (grid[i][y0]==0) {
if (xi) {
for (j=x-1;j=i ;j-- ) {
if (grid[j][y]!=0) {
k=0;
break;
}
else { k=1; }
}
if (k==1) {
rowPassOne();
}
}
if (xi) {
for (j=x+1;j=i;j++ ) {
if (grid[j][y]!=0) {
k=0;
break;
}
else { k=1; }
}
if (k==1) {
rowPassOne();
}
}
if (x==i) {
rowPassOne();
}
}
if (k==2){
if (y0==y) {
remove();
}
if (y0y) {
for (n=y0;n=y-1 ;n++ ) {
if (grid[i][n]!=0) {
k=0;
break;
}
if(grid[i][n]==0 n==y-1) {
remove();
}
}
}
if (y0y) {
for (n=y0;n=y+1 ;n--) {
if (grid[i][n]!=0) {
k=0;
break;
}
if(grid[i][n]==0 n==y+1) {
remove();
}
}
}
}
}
}
}
public void linePassOne(){
if (y0j){ //第一按钮同行空按钮在左边
for (i=y0-1;i=j ;i-- ){ //判断第一按钮同左侧空按钮之间有没按钮
if (grid[x0][i]!=0) {
k=0;
break;
}
else { k=2; } //K=2说明通过了第二次验证
}
}
if (y0j){ //第一按钮同行空按钮在与第二按钮之间
for (i=y0+1;i=j ;i++){
if (grid[x0][i]!=0) {
k=0;
break;
}
else{ k=2; }
}
}
}
public void rowPassOne(){
if (x0i) {
for (j=x0-1;j=i ;j-- ) {
if (grid[j][y0]!=0) {
k=0;
break;
}
else { k=2; }
}
}
if (x0i) {
for (j=x0+1;j=i ;j++ ) {
if (grid[j][y0]!=0) {
k=0;
break;
}
else { k=2; }
}
}
}
public void remove(){
firstButton.setVisible(false);
secondButton.setVisible(false);
fraction();
pressInformation=false;
k=0;
grid[x0][y0]=0;
grid[x][y]=0;
}
public void actionPerformed(ActionEvent e) {
if(e.getSource()==newlyButton){
int grid[][] = new int[8][7];
this.grid = grid;
randomBuild();
mainFrame.setVisible(false);
pressInformation=false;
init();
}
if(e.getSource()==exitButton)
System.exit(0);
if(e.getSource()==resetButton)
reload();
for(int cols = 0;cols 6;cols++){
for(int rows = 0;rows 5;rows++ ){
if(e.getSource()==diamondsButton[cols][rows])
estimateEven(cols+1,rows+1,diamondsButton[cols][rows]);
}
}
}
public static void main(String[] args) {
lianliankan llk = new lianliankan();
llk.randomBuild();
llk.init();
}
}
//old 998 lines
//new 318 lines
基于JAVA的3D坦克游戏源代码
JAVA猜数字小游戏源代码
/*1、编写一个猜数字的游戏，由电脑随机产生一个100以内的整数，让用户去猜，如果用户猜的比电脑大，则输出“大了，再小点！”，反之则输出“小了，再大点！”，用户总共只能猜十次，并根据用户正确猜出答案所用的次数输出相应的信息，如：只用一次就猜对，输出“你是个天才！”，八次才猜对，输出“笨死了！”,如果十次还没有猜对，则游戏结束！*/
import java.util.*;
import java.io.*;
public class CaiShu{
public static void main(String[] args) throws IOException{
Random a=new Random();
int num=a.nextInt(100);
System.out.println("请输入一个100以内的整数：");
for (int i=0;i=9;i++){
BufferedReader bf=new BufferedReader(new InputStreamReader(System.in));
String str=bf.readLine();
int shu=Integer.parseInt(str);
if (shunum)
System.out.println("输入的数大了，输小点的！");
else if (shunum)
System.out.println("输入的数小了，输大点的！");
else {
System.out.println("恭喜你，猜对了！");
if (i=2)
System.out.println("你真是个天才！");
else if (i=6)
System.out.println("还将就，你过关了！");
else if (i=8)
System.out.println("但是你还……真笨！");
else
System.out.println("你和猪没有两样了！");
break;}
}
}
}
用JAVA编程的通过SQL连接数据库的商品库存管理系统的源代码
package com.company.dao;
import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class BaseDao {
// 数据库驱动
String driver = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
//url
String url = "jdbc:sqlserver://数据库ip:端口号;databaseName=数据库名;";
//用户名
String uname = "数据库用户名";
//密码
String pwd = "数据库密码";
/**
* 获得连接对象
* @return
*/
protected Connection getCon(){
//返回的连接
Connection con = null;
try {
//载入驱动
Class.forName(driver);
//得到连接
con = DriverManager.getConnection(url, uname, pwd);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return con;
}
/**
* 关闭数据库
* @param con
* @param stmt
* @param rs
*/
protected void closeDB(Connection con, Statement stmt, ResultSet rs){
if(rs != null){
try {
//关闭结果集
rs.close();
rs = null;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if(stmt != null){
try {
//关闭语句对象
stmt.close();
stmt = null;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if(con != null){
try {
//关闭连接对象
con.close();
con = null;
} catch (SQLException e) {
e.printStackTrace();
}
}
}
protected void closeDB(Connection con, PreparedStatement pstmt, ResultSet rs){
if(rs != null){
//关闭结果集
try {
rs.close();
rs = null;
} catch (SQLException e) {
e.printStackTrace();
}
}
if(pstmt != null){
try {
pstmt.close();
pstmt = null;
} catch (SQLException e) {
e.printStackTrace();
}
}
if(con != null){
try {
con.close();
con = null;
} catch (SQLException e) {
e.printStackTrace();
}
}
}
这个是我写的一个基本的连接sql2005数据库的代码,.! 不知道你能不能用,! 你看一下吧, 连接的时候需要sqljdbc.jar数据库驱动,!
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！
java：哪里能看到JDK的源代码？
你安装JDK的目录下，有个src.zip文件，这个就是JDK源代码的java文件。
你可以解压来查看，但，最好是关联到IDE如 eclipse 中（不需解压），然后 CTRL + 点击就可以查看到源代码了。
如下图：
当前名称：wmsjava源代码,wms 源代码
标题来源：
http://www.cdkjz.cn/article/hcjdic.html
