用百度搜索一下，就用“JAVA源代码“做为搜索条件。一般能找到很多网站。
新洲网站制作公司哪家好，找成都创新互联！从网页设计、网站建设、微信开发、APP开发、成都响应式网站建设等网站项目制作，到程序开发，运营维护。成都创新互联自2013年创立以来到现在10年的时间，我们拥有了丰富的建站经验和运维经验，来保证我们的工作的顺利进行。专注于网站建设就选成都创新互联。
要学JAVA最好还是找本书看一看。JAVA能做的东西很多，你要决定你的主攻方向然后就去找相应的资料。
你要学哪方面：
JAVA应用程序开发，
JAVA网络开发：JSP，APPLET。
JAVA手持设备软件开发，像手机软件等。
如果对程序还不是很懂，最好找本JAVA入门级的书看看，然后再决定。
电子商务（ElectronicCommerce）是互联网上出现的新概念。它是利用计算机技术、网络技术和远程通信技术，实现整个商务过程中的电子化、数字化和网络化。近年来它已经被广泛使用，给人们带来了便利，并逐渐改变了人们的生活方式。根据电子商务专业教学计划、电子商务基本理论知识和操作技能等要求，开发一套模拟的“电子商务实验系统”软件，既能满足教学需求，也能使学生在一个逼真的环境中进行电子商务全过程的操作实验。
国内的C2C交易系统多数是用ASP，PHP技术实现的，而基于JSP的系统较少。Sun Microsystems所开发的JSP以Java为平台，利用Java纯面向对象编程语言的巨大优势（跨平台性即一次编译处处运行的特点），给我们的动态网页设计带来了很大的方便。
本系统利用JSP + JavaBeans + Mysql实现了“网上家电销售系统”，C2C实现电子商务中消费者对消费者的个人交易模式。本文对系统的需求分析、总体设计及详细设计进行了详细地阐述，主要实现了以下功能：用户注册、用户登录、商品销售、购买与销售信息发布、购物车、订单生成与查询、后台管理。最终实现完成了该系统。
package test;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java点虐 .HttpURLConnection;
import java点虐 .URL;
public class HttpTest {
private String u;
private String encoding;
public static void main(String[] args) throws Exception {
HttpTest client = new HttpTest("", "UTF-8");
client.run();
}
public HttpTest(String u, String encoding) {
this.u = u;
this.encoding = encoding;
}
public void run() throws Exception {
URL url = new URL(u);// 根据链接（字符串格式），生成一个URL对象
HttpURLConnection urlConnection = (HttpURLConnection) url
.openConnection();// 打开URL
BufferedReader reader = new BufferedReader(new InputStreamReader(
urlConnection.getInputStream(), encoding));// 得到输入流，即获得了网页的内容
String line; // 读取输入流的数据，并显示
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
}
}
根据具体问题类型，进行步骤拆解／原因原理分析／内容拓展等。
具体步骤如下：／导致这种情况的原因主要是……
java swing 登陆界面code
/*
* Login.java
*
* Created on __DATE__, __TIME__
*/
package com.agen.library.window;
import java.awt.Image;
import java.awt.Toolkit;
import javax.swing.JOptionPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import com.agen.library.factory.DAOFactory;
import com.agen.library.util.GlobalUser;
import com.agen.library.vo.User;
/**
*
* @author __USER__
*/
public class Login extends javax.swing.JFrame {
/**
*
*/
private static final long serialVersionUID = -2176093732040600809L;
/** Creates new form Login */
public Login() {
super("易云图书管理软件V1.0");
Image ime = Toolkit.getDefaultToolkit().getImage(
getClass().getResource("/images/ico.png"));
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnsupportedLookAndFeelException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
setIconImage(ime);
initComponents();
setLocationRelativeTo(null);
this.setResizable(false);
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
// GEN-BEGIN:initComponents
// editor-fold defaultstate="collapsed" desc="Generated Code"
private void initComponents() {
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
jTextField1 = new javax.swing.JTextField();
jPasswordField1 = new javax.swing.JPasswordField();
jButton1 = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
jLabel1 = new javax.swing.JLabel();
jMenuBar1 = new javax.swing.JMenuBar();
jMenu1 = new javax.swing.JMenu();
jMenuItem1 = new javax.swing.JMenuItem();
jMenu2 = new javax.swing.JMenu();
jMenuItem2 = new javax.swing.JMenuItem();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
addKeyListener(new java.awt.event.KeyAdapter() {
public void keyPressed(java.awt.event.KeyEvent evt) {
formKeyPressed(evt);
}
public void keyTyped(java.awt.event.KeyEvent evt) {
formKeyTyped(evt);
}
});
jLabel2.setFont(new java.awt.Font("微软雅黑", 0, 14));
jLabel2.setText("\u7528\u6237\u540d\uff1a");
jLabel3.setFont(new java.awt.Font("微软雅黑", 0, 14));
jLabel3.setText("\u5bc6 \u7801\uff1a");
jTextField1.setFont(new java.awt.Font("微软雅黑", 0, 14));
jTextField1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jTextField1ActionPerformed(evt);
}
});
jPasswordField1.setFont(new java.awt.Font("微软雅黑", 0, 12));
jPasswordField1.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyTyped(java.awt.event.KeyEvent evt) {
jPasswordField1KeyTyped(evt);
}
});
jButton1.setBackground(new java.awt.Color(223, 216, 216));
jButton1.setFont(new java.awt.Font("微软雅黑", 0, 14));
jButton1.setText("\u767b\u9646");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jButton2.setBackground(new java.awt.Color(223, 216, 216));
jButton2.setFont(new java.awt.Font("微软雅黑", 0, 14));
jButton2.setText("\u53d6\u6d88");
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
jLabel1.setIcon(new javax.swing.ImageIcon(
getClass().getResource("/images/login_main.jpg"))); // NOI18N
jMenu1.setText("File");
jMenu1.setFont(new java.awt.Font("微软雅黑", 0, 14));
jMenuItem1.setAccelerator(javax.swing.KeyStroke.getKeyStroke(
java.awt.event.KeyEvent.VK_Q,
java.awt.event.InputEvent.CTRL_MASK));
jMenuItem1.setText("Exit");
jMenuItem1.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
jMenuItem1MouseClicked(evt);
}
});
jMenuItem1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jMenuItem1ActionPerformed(evt);
}
});
jMenu1.add(jMenuItem1);
jMenuBar1.add(jMenu1);
jMenu2.setText("Help");
jMenu2.setFont(new java.awt.Font("微软雅黑", 0, 14));
jMenuItem2.setText("About");
jMenuItem2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jMenuItem2ActionPerformed(evt);
}
});
jMenu2.add(jMenuItem2);
jMenuBar1.add(jMenu2);
setJMenuBar(jMenuBar1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(
getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(layout
.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel1)
.addGroup(
layout.createSequentialGroup()
.addContainerGap()
.addGroup(
layout.createParallelGroup(
javax.swing.GroupLayout.Alignment.TRAILING,
false)
.addComponent(
jLabel2,
javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(
javax.swing.GroupLayout.Alignment.LEADING,
layout.createSequentialGroup()
.addComponent(
jLabel3)
.addPreferredGap(
javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(
layout.createParallelGroup(
javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(
layout.createSequentialGroup()
.addGap(10,
10,
10)
.addComponent(
jButton1)
.addGap(47,
47,
47)
.addComponent(
jButton2))
.addComponent(
jPasswordField1)
.addComponent(
jTextField1,
javax.swing.GroupLayout.DEFAULT_SIZE,
197,
Short.MAX_VALUE))
.addContainerGap()))));
layout.setVerticalGroup(layout
.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(
layout.createSequentialGroup()
.addComponent(jLabel1)
.addPreferredGap(
javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(
layout.createParallelGroup(
javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(
jTextField1,
javax.swing.GroupLayout.PREFERRED_SIZE,
24,
javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(
javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(
layout.createParallelGroup(
javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(
jPasswordField1,
javax.swing.GroupLayout.PREFERRED_SIZE,
23,
javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(
javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(
layout.createParallelGroup(
javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton1)
.addComponent(jButton2))
.addContainerGap(
javax.swing.GroupLayout.DEFAULT_SIZE,
Short.MAX_VALUE)));
pack();
}// /editor-fold
// GEN-END:initComponents
private void jMenuItem2ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
About.start();
}
private void jPasswordField1KeyTyped(java.awt.event.KeyEvent evt) {
if (evt.getKeyChar() == '\n') {
String name = jTextField1.getText(); // 获取用户名
String pass = String.valueOf(jPasswordField1.getPassword());// 获取密码
User user = null;
// 未输入用户名
if (name.equals("") || name == null) {
JOptionPane.showMessageDialog(this, "用户名不允许为空！", "cuowu", 0);
return;
}
try {
user = DAOFactory.getIUserDAOInstance().findById(name);
if (user != null) {
if (user.getPass() != null user.getPass().equals(pass)) {
GlobalUser.LOGIN_USER = user; // 记录当前用户
// 进入主界面
Main.start();
this.dispose();
} else {
JOptionPane.showMessageDialog(this, "用户名或密码错误!");
return;
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (user == null) {
JOptionPane.showMessageDialog(this, "用户名或密码错误!", "消息", 0);
return;
}
}
}
private void formKeyTyped(java.awt.event.KeyEvent evt) {
}
private void formKeyPressed(java.awt.event.KeyEvent evt) {
}
private void jTextField1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
jTextField1.setText("");
jPasswordField1.setText("");
jTextField1.requestFocus();
}
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
String name = jTextField1.getText(); // 获取用户名
String pass = String.valueOf(jPasswordField1.getPassword());// 获取密码
User user = null;
// 未输入用户名
if (name.equals("")) {
JOptionPane.showMessageDialog(this, "用户名不允许为空！");
return;
}
try {
user = DAOFactory.getIUserDAOInstance().findById(name);
if (user != null) {
if (user.getPass() != null user.getPass().equals(pass)) {
GlobalUser.LOGIN_USER = user; // 记录当前用户
// 进入主界面
Main.start();
this.dispose();
} else {
JOptionPane.showMessageDialog(this, "用户名或密码错误!", "消息", 0);
return;
}
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (user == null) {
JOptionPane.showMessageDialog(this, "用户名或密码错误!", "消息", 0);
return;
}
}
private void jMenuItem1ActionPerformed(java.awt.event.ActionEvent evt) {
if (JOptionPane.showConfirmDialog(this, "你确定要退出吗？", "提示",
JOptionPane.YES_NO_OPTION) == JOptionPane.YES_OPTION) {
System.exit(0);
}
}
private void jMenuItem1MouseClicked(java.awt.event.MouseEvent evt) {
System.exit(1);
}
/**
* @param args
* the command line arguments
*/
public static void main(String args[]) {
// System.out.println(Login.class.getResource("src/images/images/login_main.jpg"));
// new javax.swing.ImageIcon(
// Login.class.getResource("../../../../images/login_main.jpg"));
// new Login().setVisible(true);
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Login().setVisible(true);
}
});
}
// GEN-BEGIN:variables
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JMenu jMenu1;
private javax.swing.JMenu jMenu2;
private javax.swing.JMenuBar jMenuBar1;
private javax.swing.JMenuItem jMenuItem1;
private javax.swing.JMenuItem jMenuItem2;
private javax.swing.JPasswordField jPasswordField1;
private javax.swing.JTextField jTextField1;
// End of variables declaration//GEN-END:variables
}
