JAVA简单实现用户登录注册

2019-07-03 19:52:32

第一篇初次写不太熟练，将一些基础的实现，记录下来。

本片代码主要有Java的桌面图形界面，Java I/O流，JDBC等等内容实现用户登录，在此地基础上添加了用户注册。代码相当的简陋，但是简单，容易理解。

数据库使用Start SampServer实现

源码：

加载数据库驱动，获取数据库连接

package 包位置

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 JdbcRe {

static {

String driverName="com.mysql.jdbc.Driver";

String url="jdbc:mysql://localhost:3306/abc";

String name="root";

String passwd="";

}

public static void locadClass() throws ClassNotFoundException {

//加载驱动

String driverName="com.mysql.jdbc.Driver";

Class.forName(driverName);

}

public static Connection getConnection() throws Exception {

String url="jdbc:mysql://localhost:3306/abc";

String name="root";

String passwd="";

//获得连接

Connection conn = DriverManager.getConnection(url, name, passwd);

return conn;

}

public static void result(Connection conn, Statement stam) {

if (conn != null) {

try {

conn.close();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

conn = null;

}

if (stam != null) {

try {

stam.close();

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

stam = null;

}

注册代码

package 包位置

import java.awt.Component;

import java.awt.FlowLayout;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.Statement;

import javax.swing.JButton;

import javax.swing.JCheckBox;

import javax.swing.JComboBox;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

import javax.swing.JPasswordField;

import javax.swing.JRadioButton;

import javax.swing.JTextArea;

import javax.swing.JTextField;

import javax.swing.SwingConstants;

public class Register extends JFrame implements ActionListener{

JPanel p1,p2,p3,p4,p5,p6,p7,p8;

JLabel l1,l2,l3,l4,l5,l6,l7,l8;

JTextField j1,j4,j5,j6,j7;

JPasswordField j2,j3;

JRadioButton r1,r2;

JCheckBox ck1,ck2,ck3,ck4;

JTextArea adddr;

JComboBox degree;

JButton bu1,bu2;

Connection conn;

Statement stam;

public Register() {

super("用户注册");

this.setLayout(new GridLayout(8,1));

p1 =new JPanel(new FlowLayout(FlowLayout.LEFT));

l1 =new JLabel("用户名：");

j1=new JTextField(18);

p1.add(l1);

p1.add(j1);

this.add(p1);

p2 =new JPanel(new FlowLayout(FlowLayout.LEFT));

l2 =new JLabel("密码：");

j2=new JPasswordField(19);

p2.add(l2);

p2.add(j2);

this.add(p2);

p3 =new JPanel(new FlowLayout(FlowLayout.LEFT));

l3 =new JLabel("确认密码：");

j3=new JPasswordField(16);

p3.add(l3);

p3.add(j3);

this.add(p3);

p4 =new JPanel(new FlowLayout(FlowLayout.LEFT));

l4 =new JLabel("确性别：");

r1=new JRadioButton("男");

r2=new JRadioButton("女");

this.r1.setSelected(true);

p4.add(l4);

p4.add(r1);

p4.add(r2);

this.add(p4);

p5 =new JPanel(new FlowLayout(FlowLayout.LEFT));

l5 =new JLabel("爱好：");

ck1=new JCheckBox("阅读");

ck2=new JCheckBox("上网");

ck3=new JCheckBox("游泳");

ck4=new JCheckBox("旅游");

p5.add(l5);

p5.add(ck1);

p5.add(ck2);

p5.add(ck3);

p5.add(ck4);

this.add(p5);

p6 =new JPanel(new FlowLayout(FlowLayout.LEFT));

l6 =new JLabel("地址：");

adddr =new JTextArea(2,19);

p6.add(l6);

p6.add(adddr);

this.add(p6);

p7 =new JPanel(new FlowLayout(FlowLayout.LEFT));

l7 =new JLabel("学历：");

String str[]= {"小学","初中","高中","大学"};

degree=new JComboBox(str);

p7.add(l7);

p7.add(degree);

this.add(p7);

p8 =new JPanel(new FlowLayout(FlowLayout.CENTER));

bu1=new JButton("注册");

bu2=new JButton("取消");

p8.add(bu1);

p8.add(bu2);

this.add(p8);

//创建监听

awtEvent();

}

public static void main(String[] args) {

r.setVisible(true);

r.setSize(300, 400);

r.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

//监听

private void awtEvent() {

//单选框互斥

r1.addActionListener(new ActionListener() {

@Override

public void actionPerformed(ActionEvent e) {

// TODO Auto-generated method stub

if(r1.isSelected()){

r2.setSelected(false);

}

});

r2.addActionListener(new ActionListener() {

@Override

public void actionPerformed(ActionEvent e) {

// TODO Auto-generated method stub

if(r2.isSelected()){

r1.setSelected(false);

}

});

//注册按钮监听

bu1.addActionListener(this);

//取消按钮监听代码

bu2.addActionListener(new ActionListener() {

@Override

public void actionPerformed(ActionEvent e) {

dispose();

}

});

}

@Override

public void actionPerformed(ActionEvent e) {

//获取选取的性别

String s1=null;

if(r1.isSelected()) {

s1="男";

}else {

s1="女";

}

//获取复选框中的值

String info ="";

//通过面板属性名获取到该面板上的所有组件

for(Component c:p5.getComponents()){

//通过 instanceof方法筛选复选框组件

if(c instanceof JCheckBox){

//判断复选框组件是否被选中

if(((JCheckBox) c).isSelected()){

//获取该复选框组件信息

info += ((JCheckBox)c).getText();

}

//下拉列表框中的值

String x = degree.getSelectedItem().toString();

//判断用户名和密码是否为空

judge();

//判断用户名是否重复

userName();

//两次密码是否一致

pwdName();

if(e.getSource()==bu1) {

try {

//加载数据库驱动

conn=JdbcRe.getConnection();

//创建执行sql语句的对象

stam=conn.createStatement();

//编写sql语句

String sql="insert into user values('"+j1.getText()+"','"+j2.getText()+"','"+j3.getText()+"','"+s1+"','"+info+"','"+adddr.getText()+"','"+x+"')";

//执行sql语句

stam.execute(sql);

//提示框

JOptionPane.showMessageDialog(null, "注册成功!!!!!");

//关闭注册界面窗体

this.dispose();

//打开登录窗体

User user=new User();

user.setVisible(true);

user.setSize(600,500);

user.setLocation(600,200);

}catch (Exception e1) {

e1.printStackTrace();

}finally {

JdbcRe.result(conn, stam);

}

//判断用户名密码是否为空

private void judge() {

if (j1.getText().isEmpty()) {// 判断用户名是否为空

this.dispose();

JOptionPane.showMessageDialog(this, "用户名不能为空！", "警告信息", JOptionPane.WARNING_MESSAGE);

r.setVisible(true);

r.setSize(300, 400);

r.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

return;

}

if (new String(j2.getText()).isEmpty()) {// 判断密码是否为空

this.dispose();

JOptionPane.showMessageDialog(this, "密码不能为空！", "警告信息", JOptionPane.WARNING_MESSAGE);

r.setVisible(true);

r.setSize(300, 400);

r.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

return;

}

if (new String(j3.getText()).isEmpty()) {// 判断确认密码是否为空

this.dispose();

JOptionPane.showMessageDialog(this, "确认密码不能为空！", "警告信息", JOptionPane.WARNING_MESSAGE);

r.setVisible(true);

r.setSize(300, 400);

r.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

return;

}

//判断新的用户是否和原用户名有重复

private void userName() {

try {

conn=JdbcRe.getConnection();

stam=(Statement)conn.createStatement();

//编写SQL语句

String sql="select id num from User where id='"+j1.getText()+"'";

ResultSet rs=stam.executeQuery(sql);

int num=0;

if(rs!=null&&rs.next()) {

num=rs.getInt("num");

System.out.println(num);

}

//判断用户名是否有相同

if (num>0) {

JOptionPane.showMessageDialog(this, "用户名已使用，请重新选取","警告消息",JOptionPane.WARNING_MESSAGE);

this.dispose();

r.setVisible(true);

r.setSize(300, 400);

r.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

return;

}

} catch (Exception e) {

e.printStackTrace();

}

//判断相关用户的密码和确认密码相同

private void pwdName() {

if (j2.equals(j3)) {

JOptionPane.showMessageDialog(this, "两次密码不相同","警告消息",JOptionPane.WARNING_MESSAGE);

r.setVisible(true);

r.setSize(300, 400);

r.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

return;

}

用户登录界面代码

package 包位置

import java.awt.FlowLayout;

import java.awt.Font;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.KeyAdapter;

import java.awt.event.KeyEvent;

import java.awt.event.MouseEvent;

import java.awt.event.MouseListener;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

import java.sql.Connection;

import java.sql.ResultSet;

import java.sql.Statement;

import java.util.Random;

import javax.swing.BorderFactory;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

import javax.swing.JPasswordField;

import javax.swing.JRadioButton;

import javax.swing.JTextField;

import chat.ChatRoomClient;

import chat.ChatRoomServer;

import cn.jhc.util.ComStr;

import cn.jhc.util.RandomYzm;

import cn.jhc.view.MainWinow;

public class User extends JFrame implements ActionListener,MouseListener{

String rYzm;

JPanel p1,p2,p3,p4;

JLabel j1,j2,j3,lyzm;

JTextField t1,inYzm;

JPasswordField t2;

JButton b,b1,yzm,b2;

JRadioButton jr1;

Connection conn;

Statement stam;

public User() {

super("用户登录界面");

this.setLayout(new GridLayout(4,1));

p1=new JPanel(null);

p2=new JPanel(null);

p3=new JPanel(null);

p4=new JPanel(null);

JLabel jl1=new JLabel("大傻逼登录系统");

jl1.setFont(new Font("宋体",Font.BOLD,20));

jl1.setBounds(180,0, 170, 80);

j1=new JLabel("用户名：");

j1.setFont(new Font("宋体",Font.BOLD,20));

j1.setBounds(90,0,110,30);

j2=new JLabel("密码：");

j2.setFont(new Font("宋体",Font.BOLD,20));

j2.setBounds(90,80,110,30);

lyzm =new JLabel("验证码:");

lyzm.setFont(new Font("宋体",Font.BOLD,20));

lyzm.setBounds(90,45,110,30);

//用于输入验证码的文本框

inYzm =new JTextField();

inYzm.setFont(new Font("宋体",Font.BOLD,20));

inYzm.setBounds(190,45,190,30);

//显示验证码的按钮

yzm=new JButton();

rYzm = RandomYzm.getYzm();

yzm.setFont(new Font("宋体",Font.BOLD,20));

yzm.setBounds(400,45,130,30);

yzm.setOpaque(false);

yzm.setBorder(BorderFactory.createCompoundBorder(null,null));

yzm.addActionListener(new ActionListener() {

@Override

public void actionPerformed(ActionEvent evt) {

yzmAction(evt);

}

});

//用户名输入框

t1=new JTextField(9);

t1.setFont(new Font("宋体",Font.BOLD,20));

t1.setBounds(190,0,190,30);

//用户密码框

t2=new JPasswordField(9);

t2.setFont(new Font("宋体",Font.BOLD,20));

t2.setBounds(190,80,190,30);

b=new JButton("登录");

b.setFont(new Font("宋体",Font.BOLD,20));

b.setBounds(90, 20,290, 30);

b1=new JButton("注册");

b1.setFont(new Font("宋体",Font.BOLD,20));

b1.setBounds(400, 0, 130, 30);

b2=new JButton("修改密码");

b2.setFont(new Font("宋体",Font.BOLD,20));

b2.setBounds(400, 80, 130, 30);

jr1=new JRadioButton("记住密码");

jr1.setFont(new Font("宋体",Font.BOLD,20));

jr1.setBounds(400,20, 160, 30);

jr1.setSelected(false);

p1.add(jl1);

p2.add(j1);

p2.add(j2);

p2.add(b1);

p2.add(t1);

p2.add(t2);

p2.add(b2);

p3.add(lyzm);

p3.add(inYzm);

p3.add(yzm);

p4.add(b);

p4.add(jr1);

this.add(p1);

this.add(p2);

this.add(p3);

this.add(p4);

//创建监听

awtEvent();

//获取相应的用户名和密码

addPassword();

}

private void awtEvent() {

//登录按键监听

b.addActionListener(this);

//注册按键监听

b1.addMouseListener(this);

//修改密码监听

b2.addActionListener(this);

}

//用于刷新验证码

private void yzmAction(ActionEvent evt) {

//重新获取验证码

rYzm=RandomYzm.getYzm();

//设置显示的验证码

yzm.setText(rYzm);

}

private void addPassword() {

try {

BufferedReader buf=new BufferedReader(new FileReader("user.txt"));

String lien = buf.readLine();

if(lien!= null) {

String[] users=lien.split(" ");

t1.setText(users[0]);

t2.setText(users[1]);

}

buf.close();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

public static void main(String[] args) {

User user=new User();

user.setVisible(true);

user.setSize(600,500);

user.setLocation(600,200);

user.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

@Override

public void actionPerformed(ActionEvent e) {

if(e.getSource()==b) {

try {

conn=JdbcRe.getConnection();

stam=(Statement)conn.createStatement();

//编写SQL语句

String sql="select id,pwd from User where id='"+t1.getText()+"'and pwd='"+t2.getText()+"'";

//执行SQL语句

ResultSet rs=stam.executeQuery(sql);

if(rs.next()) {

String get_InYzm=inYzm.getText();

System.out.println("获取到相应账号");

if(ComStr.compar2Str(get_InYzm, rYzm)){

System.out.println("验证码正确");

if(jr1.isSelected()){

FileWriter fWriter=new FileWriter("user.txt");

fWriter.write(t1.getText());

fWriter.write(" ");

fWriter.write(t2.getText());

fWriter.close();

}

this.dispose();//关闭窗口

String name=JOptionPane.showInputDialog(this,"请输入你的昵称：");

String num="ww";

//记住密码功能中用流将数据传到username.txt中

FileWriter f=new FileWriter("username.txt");

f.write(num);

f.write(" ");

f.write(name);

f.flush();

JOptionPane.showMessageDialog(null, "登录成功!");

}else {

JOptionPane.showMessageDialog(this, "验证码错误");

inYzm.setText("");

}

}else {

JOptionPane.showMessageDialog(null, "密码或账号错误,登录失败!","标题",JOptionPane.ERROR_MESSAGE);

t1.setText("");

t2.setText("");

}

} catch (Exception e1) {

e1.printStackTrace();

}

if(e.getSource()==b2) {

this.dispose();

UserTrue userTrue=new UserTrue();

userTrue.setVisible(true);

userTrue.setSize(370,300);

userTrue.setLocation(300,300);

}

@Override

public void mouseClicked(MouseEvent e) {

this.dispose();

}

@Override

public void mousePressed(MouseEvent e) {

// TODO Auto-generated method stub

}

@Override

public void mouseReleased(MouseEvent e) {

// TODO Auto-generated method stub

}

@Override

public void mouseEntered(MouseEvent e) {

// TODO Auto-generated method stub

}

@Override

public void mouseExited(MouseEvent e) {

// TODO Auto-generated method stub

}

用户是否存在验证

package 包位置;

import java.awt.FlowLayout;

import java.awt.Font;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.io.FileWriter;

import java.io.IOException;

import java.sql.Connection;

import java.sql.ResultSet;

import java.sql.Statement;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

import javax.swing.JPasswordField;

import javax.swing.JTextField;

public class UserTrue extends JFrame implements ActionListener{

JPanel p1;

JLabel l1;

JTextField j1;

JPanel p2;

JLabel l2;

JPasswordField j2;

JPanel p3;

JLabel l3;

JPasswordField j3;

JPanel p4;

JButton bu1;

Connection conn;

Statement stam;

public UserTrue() {

super("用户验证");

this.setLayout(new GridLayout(4,1));

p1 =new JPanel(null);

l1 =new JLabel("用户名：");

l1.setFont(new Font("宋体",Font.BOLD,20));

l1.setBounds(50, 20, 120, 30);

j1=new JTextField(10);

j1.setFont(new Font("宋体",Font.BOLD,20));

j1.setBounds(160, 20, 130, 30);

p1.add(l1);

p1.add(j1);

this.add(p1);

p2 =new JPanel(null);

l2 =new JLabel("密码：");

l2.setFont(new Font("宋体",Font.BOLD,20));

l2.setBounds(50, 20, 120, 30);

j2=new JPasswordField(10);

j2.setFont(new Font("宋体",Font.BOLD,20));

j2.setBounds(160, 20, 130, 30);

p2.add(l2);

p2.add(j2);

this.add(p2);

p3 =new JPanel(null);

l3 =new JLabel("确认密码：");

l3.setFont(new Font("宋体",Font.BOLD,20));

l3.setBounds(50, 20, 120, 30);

j3=new JPasswordField(10);

j3.setFont(new Font("宋体",Font.BOLD,20));

j3.setBounds(160, 20, 130, 30);

p3.add(l3);

p3.add(j3);

this.add(p3);

p4 =new JPanel(null);

bu1=new JButton("确认");

bu1.addActionListener(this);

bu1.setBounds(100, 20, 120,30);

p4.add(bu1);

this.add(p4);

}

public static void main(String[] args) {

UserTrue userTrue=new UserTrue();

userTrue.setVisible(true);

userTrue.setSize(370,300);

userTrue.setLocation(300,300);

userTrue.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

@Override

public void actionPerformed(ActionEvent e) {

if(e.getSource()==bu1) {

try {

//加载驱动

conn=JdbcRe.getConnection();

//创建sql语句对象

stam=conn.createStatement();

//创建sql语句

String sql="select id,pwd,loginName from user where id='"+j1.getText()+"' and pwd='"+j2.getText()+"' and loginName='"+j3.getText()+"'";

//执行sql语句

ResultSet rs=stam.executeQuery(sql);

if(rs.next()) {

this.dispose();

UserModi userTrue=new UserModi();

userTrue.setVisible(true);

userTrue.setSize(370,300);

userTrue.setLocation(300,300);

userTrue.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}else {

j1.setText("");

j2.setText("");

j3.setText("");

JOptionPane.showMessageDialog(this, "用户名或密码不存在");

}

} catch (Exception e1) {

// TODO Auto-generated catch block

e1.printStackTrace();

}

try {

FileWriter fileWriter=new FileWriter("nameExit.txt");

fileWriter.write(j1.getText());

fileWriter.flush();

fileWriter.close();

} catch (IOException e1) {

// TODO Auto-generated catch block

e1.printStackTrace();

}

用户修改密码代码

Package包位置

import java.awt.Font;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.io.BufferedReader;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.sql.Connection;

import java.sql.ResultSet;

import java.sql.Statement;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JOptionPane;

import javax.swing.JPanel;

import javax.swing.JPasswordField;

import javax.swing.JTextField;

public class UserModi extends JFrame implements ActionListener{

JPanel p1,p2,p3,p4,p5;

JLabel l1,l2,l3;

JTextField j1;

JPasswordField j2,j3;

JButton bu1,bu2;

Connection conn;

Statement stam;

public UserModi() {

super("用户修改");

this.setLayout(new GridLayout(4,1));

p1 =new JPanel(null);

l1 =new JLabel("用户名：");

l1.setFont(new Font("宋体",Font.BOLD,20));

l1.setBounds(50, 20, 120, 30);

j1=new JTextField();

//j1=new JLabel("12");

j1.setFont(new Font("宋体",Font.BOLD,20));

j1.setBounds(160, 20, 130, 30);

//j1.setEditable(false);

p1.add(l1);

p1.add(j1);

this.add(p1);

try {

BufferedReader bufferedReader=new BufferedReader(new FileReader("nameExit.txt"));

String lenString=bufferedReader.readLine();

if (lenString!=null) {

String[] aaStrings=lenString.split(" ");

j1.setText(aaStrings[0]);

}

// bufferedReader.close();

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

p2 =new JPanel(null);

l2 =new JLabel("密码：");

l2.setFont(new Font("宋体",Font.BOLD,20));

l2.setBounds(50, 20, 120, 30);

j2=new JPasswordField(10);

j2.setFont(new Font("宋体",Font.BOLD,20));

j2.setBounds(160, 20, 130, 30);

p2.add(l2);

p2.add(j2);

this.add(p2);

p3 =new JPanel(null);

l3 =new JLabel("确认密码：");

l3.setFont(new Font("宋体",Font.BOLD,20));

l3.setBounds(50, 20, 120, 30);

j3=new JPasswordField(10);

j3.setFont(new Font("宋体",Font.BOLD,20));

j3.setBounds(160, 20, 130, 30);

p3.add(l3);

p3.add(j3);

this.add(p3);

p4 =new JPanel(null);

bu1=new JButton("确认");

bu1.addActionListener(this);

bu1.setBounds(50, 20, 120,30);

p4.add(bu1);

bu2=new JButton("退出");

bu2.setBounds(170, 20, 120,30);

bu2.addActionListener(this);

p4.add(bu2);

this.add(p4);

}

public static void main(String[] args) {

UserModi userTrue=new UserModi();

userTrue.setVisible(true);

userTrue.setSize(370,300);

userTrue.setLocation(300,300);

userTrue.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

@Override

public void actionPerformed(ActionEvent e) {

if(e.getSource()==bu1) {

try {

//加载驱动

conn=JdbcRe.getConnection();

//创建sql语句对象

stam=conn.createStatement();

//创建sql语句

String sql="update user set pwd=('"+j2.getText()+"') , loginName=('"+j3.getText()+"') where id=('"+j1.getText()+"')";

//执行sql语句

stam.execute(sql);

JOptionPane.showMessageDialog(null, "修改成功!!!!!");

//关闭修改窗体

this.dispose();

//打开登录窗体

User user=new User();

user.setVisible(true);

user.setSize(600,500);

user.setLocation(600,200);

} catch (Exception e1) {

// TODO Auto-generated catch block

e1.printStackTrace();

}

if (e.getSource()==bu2) {

j1.setText("");

this.dispose();

}

验证码判断

Package 包位置

/**

* 实现不区分大小写比较两字符串是否相等

* 输出为true false

* @author Lenovo

public class ComStr {

public static boolean compar2Str(String str1,String str2) {

char[] ch1=str1.toCharArray();//将字符串str1转换为字符数组

char[] ch2=str2.toCharArray();//将字符串str2转换为字符数组

String newStr1="";//声明转换为小写的字符串str1

String newStr2="";//声明转换为小写的字符串str1

for (int i = 0; i < ch1.length; i++) {

if(ch1[i]>=65&&ch1[i]<=90) {//如果字符串为大写就将其转换为小写

ch1[i]+=32;

}

newStr1 +=ch1[i];

}

for (int i = 0; i < ch2.length; i++) {

if(ch2[i]>=65&&ch2[i]<=90) {

ch2[i]+=32;

}

newStr2 +=ch2[i];

}

//如果两相等将输出true

if(newStr2.equals(newStr1)) {

return true;

}

return false;

}

验证码随机

Package 包位置

/**

* 用于随机产生长度为4的可变字符串

import java.util.Random;

public class RandomYzm {

public static String getYzm() {

//定义长度为4

int lenght=4;

//35个随机数

String untes="1,2,3,4,5,6,7,8,9,q,w,e,r,t,y,u,i,o,p,a,s,d,f,g,h,j,k,l,z,x,c,v,b,n,m";

//使用字符串将随机数分割开

String unte[]=untes.split(",");

//对随机数的对象进行实例化

Random rd=new Random();

//设置用于存储产生的字符串

StringBuffer buf=new StringBuffer();

for (int i = 0; i < lenght; i++) {

buf.append(unte[rd.nextInt(35)]);

}

return buf.toString();

}

JAVA简单实现用户登录注册

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