java代码，代码示例
很多朋友对于java代码和代码示例不太懂，今天就由小编来为大家分享，希望可以帮助到大家，下面一起来看看吧！
怎么写Java代码
public class Reader{
private static int nextId= 10001;//初始编号
private int id;//读者编号
private String name;//姓名
private String password;//密码
private double balance;//账户余额
private String level;//身份等级
private double discountRate;//折扣率
private int points;//积分
public Reader(String name, String password, double balance, String level){
this.id= nextId++;
this.name= name;
this.password= password;
this.balance= balance;
this.level= level;
//设置折扣率
if(level.equals("VIP")){
this.discountRate= 0.8;
} else if(level.equals("普通会员")){
this.discountRate= 0.9;
} else{
this.discountRate= 1.0;
}
}
//提供 getter和 setter方法
public int getId(){
return id;
}
public String getName(){
return name;
}
public void setName(String name){
this.name= name;
}
public String getPassword(){
return password;
}
public void setPassword(String password){
this.password= password;
}
public double getBalance(){
return balance;
}
public void setBalance(double balance){
this.balance= balance;
}
public String getLevel(){
return level;
}
public void setLevel(String level){
this.level= level;
}
public double getDiscountRate(){
return discountRate;
}
public void setDiscountRate(double discountRate){
this.discountRate= discountRate;
}
public int getPoints(){
return points;
}
public void setPoints(int points){
this.points= points;
}
}
以上代码定义了一个`Reader`类，包含读者的相关信息作为成员变量，并提供了相应的 getter和 setter方法。在构造函数中，默认将读者编号设置为自增的流水号，并根据身份等级设置相应的折扣率。
怎么写Java的代码
public class Reader{
private static int nextId= 10001;
private int readerId;
private String name;
private String password;
private double balance;
private String membership;
private double discountRate;
private int points;
public Reader(String name, String password, double balance, String membership, double discountRate){
this.readerId= nextId++;
this.name= name;
this.password= password;
this.balance= balance;
this.membership= membership;
this.discountRate= discountRate;
this.points= 0;
}
public int getReaderId(){
return readerId;
}
public String getName(){
return name;
}
public String getPassword(){
return password;
}
public double getBalance(){
return balance;
}
public String getMembership(){
return membership;
}
public double getDiscountRate(){
return discountRate;
}
public int getPoints(){
return points;
}
public void setDiscountRate(double discountRate){
this.discountRate= discountRate;
}
public void addPoints(int pointsToAdd){
this.points+= pointsToAdd;
}
public void deductBalance(double amount){
if(amount<= balance){
balance-= amount;
System.out.println("Successfully deducted"+ amount+" from balance.");
} else{
System.out.println("Insufficient balance.");
}
}
}
-成员变量：
- `readerId`：读者编号，是一个自动生成的流水号。
- `name`：读者姓名。
- `password`：读者密码。
- `balance`：账户余额。
- `membership`：身份等级，可以是"百通云员"或"非会员"。
- `discountRate`：折扣率。
- `points`：积分。
-构造函数：
-构造函数接受姓名、密码、账户余额、身份等级和折扣率作为参数，并自动分配读者编号。
-方法：
- `getReaderId()`：返回读者编号。
- `getName()`：返回读者姓名。
- `getPassword()`：返回读者密码。
- `getBalance()`：返回账户余额。
- `getMembership()`：返回身份等级。
- `getDiscountRate()`：返回折扣率。
- `getPoints()`：返回积分。
- `setDiscountRate(double discountRate)`：设置折扣率。
- `addPoints(int pointsToAdd)`：增加积分。
- `deductBalance(double amount)`：从余额中扣除指定金额。
利用java编写代码实现如下功能,需要全部代码
很简单的应用，为了节省字数，代码注释我就不加了
首先是显示层，LoinWindow：
importjava.awt.FlowLayout;
importjava.awt.GridBagConstraints;
importjava.awt.GridBagLayout;
importjava.awt.GridLayout;
importjava.awt.event.ActionEvent;
importjava.awt.event.ActionListener;
importjava.awt.event.FocusEvent;
importjava.awt.event.FocusListener;
importjavax.swing.JButton;
importjavax.swing.JFrame;
importjavax.swing.JLabel;
importjavax.swing.JOptionPane;
importjavax.swing.JPanel;
importjavax.swing.JTextField;
importjavax.swing.border.EmptyBorder;
publicclassLoinWindowextendsJFrameimplementsActionListener,FocusListener{
privateJPanelmainPanel,namePanel,btnPanel;
privateJTextFieldtfName,tfPsd;
privateJButtonbtnLogin,btnCancel;
privatestaticfinalintWIDTH=300;
privatestaticfinalintHEIGHT=200;
privateLoginServiceservice=newLoginService();
publicLoinWindow(){
super("登录窗体");
}
publicvoidlaunch(){
setSize(WIDTH,HEIGHT);
setVisible(true);
setDefaultCloseOperation(EXIT_ON_CLOSE);
GridLayoutmainLayout=newGridLayout(2,1);
mainLayout.setVgap(10);
mainPanel=newJPanel(mainLayout);
GridBagLayoutnameLayout=newGridBagLayout();
namePanel=newJPanel(nameLayout);
namePanel.setBorder(newEmptyBorder(10,10,10,10));
JLabelnameLabel=newJLabel("姓名：");
tfName=newJTextField();
JLabelpsdLabel=newJLabel("密码：");
tfPsd=newJTextField();
JLabelblank=newJLabel("");
namePanel.add(nameLabel);
namePanel.add(tfName);
namePanel.add(blank);
namePanel.add(psdLabel);
namePanel.add(tfPsd);
GridBagConstraintss=newGridBagConstraints();
s.fill=GridBagConstraints.BOTH;
s.gridwidth=1;
s.weightx=0;
s.weighty=0;
nameLayout.setConstraints(nameLabel,s);
s.gridwidth=0;
s.weightx=1;
s.weighty=0;
nameLayout.setConstraints(tfName,s);
s.gridwidth=0;
s.weightx=4;
s.weighty=0;
nameLayout.setConstraints(blank,s);
s.gridwidth=1;
s.weightx=0;
s.weighty=0;
nameLayout.setConstraints(psdLabel,s);
s.gridwidth=3;
s.weightx=1;
s.weighty=0;
nameLayout.setConstraints(tfPsd,s);
FlowLayoutbtnLayout=newFlowLayout();
btnLayout.setAlignment(FlowLayout.CENTER);
btnPanel=newJPanel(btnLayout);
btnLogin=newJButton("确定");
btnCancel=newJButton("取消");
btnPanel.add(btnLogin);
btnPanel.add(btnCancel);
btnCancel.addActionListener(this);
btnLogin.addActionListener(this);
mainPanel.add(namePanel);
mainPanel.add(btnPanel);
setContentPane(mainPanel);
tfName.addFocusListener(this);
tfPsd.addFocusListener(this);
pack();
setSize(WIDTH,HEIGHT);
setLocationRelativeTo(null);
}
@Override
publicvoidactionPerformed(ActionEvente){
Objectsource=e.getSource();
if(source==btnCancel){
System.exit(0);
}elseif(source==btnLogin){
Stringusername=tfName.getText();
Stringpassword=tfPsd.getText();
booleansuccess=service.login(username,password);
if(success){
warn("成功","登录成功！");
}else{
warn("失败","您输入的用户名或密码错误！");
}
}
}
@Override
publicvoidfocusGained(FocusEventarg0){
}
@Override
publicvoidfocusLost(FocusEvente){
Objectsource=e.getSource();
if(source==tfName){
Stringusername=tfName.getText();
try{
service.matchUsername(username);
}catch(LoginExceptione1){
warn("验证错误",e1.getMessage());
}
}elseif(source==tfPsd){
Stringpassword=tfPsd.getText();
try{
service.matchPassword(password);
}catch(LoginExceptione1){
warn("验证错误",e1.getMessage());
}
}
}
privatevoidwarn(Stringtitle,Stringmsg){
JOptionPane.showMessageDialog(null,msg,title,JOptionPane.INFORMATION_MESSAGE);
}
publicstaticvoidmain(String[]args){
newLoinWindow().launch();
}
}然后是模型层：LoginDao
publicclassLoginDao{
publicbooleanlogin(Stringusername,Stringpassword){
if(username.equals("admin")&&password.equals("12345")){
returntrue;
}
returnfalse;
}
}LoginService
importjava.util.regex.Pattern;
publicclassLoginService{
privatestaticfinalPatternLOGIN_PATTERN=Pattern.compile("[a-zA-Z]+");
privatestaticfinalPatternPASSWORD_PATTERN=Pattern.compile("[1-9]+");
privateLoginDaodao=newLoginDao();
publicbooleanmatchUsername(Stringusername)throwsLoginException{
if(null==username||username.isEmpty()){
returnfalse;
}
if(!LOGIN_PATTERN.matcher(username).matches()){
thrownewLoginException("您输入的用户名不合法，请输入英文！");
}
returntrue;
}
publicbooleanmatchPassword(Stringpassword)throwsLoginException{
if(null==password||password.isEmpty()){
returnfalse;
}
if(!PASSWORD_PATTERN.matcher(password).matches()){
thrownewLoginException("您输入的密码不合法，请输入数字！");
}
returntrue;
}
publicbooleanlogin(Stringusername,Stringpassword){
if(null==username||username.isEmpty()){
returnfalse;
}
if(null==password||password.isEmpty()){
returnfalse;
}
if(!dao.login(username,password)){
returnfalse;
}
returntrue;
}
}LoginException
publicclassLoginExceptionextendsException{
publicLoginException(Stringarg0){
super(arg0);
}
}不知道分层设计思想是不是我想的这样
关于java代码到此分享完毕，希望能帮助到您。