採用簡單的MVC設計模式，M(模型層) -> Address.java 裏面包含id，name,street,city,state,zip 等相關屬性和set，get方法
V(視圖層) -> 主要指jsp頁面，包含list.jsp,add.jsp,edit.jsp
C(控制層) -> 這裏只用一個servlet實現其增刪改查(簡單明瞭，方便理解)，並沒有用業務層的那套 service+serviceImp
項目目錄：
相關的mysql數據庫代碼：
create database addr;
use addr;
create table address(
id int primary key auto_increment,
name varchar(20),
street varchar(20),
city varchar(20),
state varchar(20),
zip varchar(20)
);
insert into address(name,street,city,state,zip) values ('AAA','永寧街','西安','aa','1101');
insert into address(name,street,city,state,zip) values ('BBB','嘉定街','上海','bb','1102');
insert into address(name,street,city,state,zip) values ('CCC','福壽街','天津','cc','1103');
insert into address(name,street,city,state,zip) values ('DDD','回民街','北京','dd','1104');
insert into address(name,street,city,state,zip) values ('EEE','健康街','武漢','ee','1105');
根據數據庫表，我們首先創建一個實體(domain)類:Address.java, 。這裏我們就不貼圖展示了
然後創建JdbcUtil.java 主要用來連接mysql數據庫：
public class JdbcUtil {
static{
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (Exception e) {
e.printStackTrace();
}
}
public static Connection getConnection() throws SQLException{
String dbUrl="jdbc:mysql://localhost:3306/addr?useUnicode=true&characterEncoding=utf8";
String dbUser="root";
String dbPassword="1101";
return DriverManager.getConnection(dbUrl,dbUser,dbPassword);
}
public static void close(Statement stmt,Connection conn) throws SQLException{
stmt.close();
conn.close();
}
}
當然代碼JdbcUtil的代碼可進行適當優化
注意：要修改成你們mysql的用戶名和密碼，
Dao層（數據訪問層）代碼編寫
public class AddressDao {
//增加
public void add(Address address){
try {
Connection conn = JdbcUtil.getConnection();
PreparedStatement pstmt = conn.prepareStatement("insert into address(name,street,city,state,zip) values(?,?,?,?,?)");
pstmt.setString(1,address.getName());
pstmt.setString(2,address.getStreet());
pstmt.setString(3,address.getCity());
pstmt.setString(4,address.getState() );
pstmt.setString(5,address.getZip() );
pstmt.executeUpdate();
JdbcUtil.close(pstmt, conn);
} catch (SQLException e) {
e.printStackTrace();
}
}
//刪除
public void delete(int id){
try{
Connection conn = JdbcUtil.getConnection();
PreparedStatement pstmt = conn.prepareStatement("delete from address where id = ?");
pstmt.setInt(1, id);
pstmt.executeUpdate();
JdbcUtil.close(pstmt, conn);
}catch(SQLException e){
e.printStackTrace();
throw new RuntimeException();
}
}
//修改
public void update(Address address){
try {
Connection conn = JdbcUtil.getConnection();
PreparedStatement pstmt = conn.prepareStatement("update address set name = ?,street = ?,city =? ,state =?,zip= ? where id = ?");
pstmt.setInt(6, address.getId());
pstmt.setString(1,address.getName());
pstmt.setString(2,address.getStreet());
pstmt.setString(3,address.getCity());
pstmt.setString(4,address.getState());
pstmt.setString(5,address.getZip());
pstmt.executeUpdate();
JdbcUtil.close(pstmt, conn);
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException();
}
}
//查詢
public List<Address> findAll(){
List<Address> list = new ArrayList<Address>();
try{
Connection conn = JdbcUtil.getConnection();
PreparedStatement pstmt = conn.prepareStatement("select * from address");
ResultSet rs = pstmt.executeQuery();
while(rs.next()){
Address address = new Address();
address.setId(rs.getInt(1));
address.setCity(rs.getString(4));
address.setStreet(rs.getString(3));
address.setState(rs.getString(5));
address.setName(rs.getString(2));
address.setZip(rs.getString(6));
list.add(address);
}
JdbcUtil.close(pstmt, conn);
}catch(SQLException e){
e.printStackTrace();
throw new RuntimeException();
}
return list;
}
//根據id查詢
public Address findById(int id){
Address address = new Address();
try{
Connection conn = JdbcUtil.getConnection();
PreparedStatement pstmt = conn.prepareStatement("select * from address where id="+id);
ResultSet rs = pstmt.executeQuery();
if(rs.next()){
address.setId(rs.getInt(1));
address.setCity(rs.getString(4));
address.setStreet(rs.getString(3));
address.setState(rs.getString(5));
address.setName(rs.getString(2));
address.setZip(rs.getString(6));
}
JdbcUtil.close(pstmt, conn);
}catch(SQLException e){
e.printStackTrace();
throw new RuntimeException();
}
return address;
}
}
servlet代碼編寫
public class AddressServlet extends HttpServlet {
// 注入dao
private AddressDao addressDao = new AddressDao();
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//設置編碼，很重要，否則頁面提交，中文會出現亂碼
request.setCharacterEncoding("UTF-8");
response.setCharacterEncoding("utf-8");
//設置路徑
String path = "list.jsp";
String method = request.getParameter("method");
//若請求的url有list
if (("list").equals(method)) {
List<Address> list = addressDao.findAll();
request.setAttribute("list", list);
}
else if (method.equals("add")) {
//注入Address實體類
Address address = new Address();
//獲取參數
String name = request.getParameter("name");
String street = request.getParameter("street");
String city = request.getParameter("city");
String state = request.getParameter("state");
String zip = request.getParameter("zip");
//設置增加的屬性
address.setName(name);
address.setStreet(street);
address.setCity(city);
address.setState(state);
address.setZip(zip);
addressDao.add(address);
<!--把新加入的數據重新加載
這點特別重要，否則刷新頁面會報空指針異常
-->
path = "AddressServlet?method=list";
}
else if (method.equals("delete")) {
//根據id來刪除
int id = Integer.parseInt(request.getParameter("id"));
addressDao.delete(id);
//要重新查詢一遍，否則會報空指針
path = "AddressServlet?method=list";
}
//跳轉編輯頁面url請求如下：
else if (method.equals("toedit")) {
int id = Integer.parseInt(request.getParameter("id"));
Address address = addressDao.findById(id);
path = "edit.jsp";
request.setAttribute("address", address);
}
else if (method.equals("edit")) {
//根據id修改
int id = Integer.parseInt(request.getParameter("id"));
String name = request.getParameter("name");
String street = request.getParameter("street");
String city = request.getParameter("city");
String state = request.getParameter("state");
String zip = request.getParameter("zip");
Address address = new Address();
address.setId(id);
address.setName(name);
address.setStreet(street);
address.setCity(city);
address.setState(state);
address.setZip(zip);
addressDao.update(address);
//把新加入的數據重新加載
path = "AddressServlet?method=list";
}
request.getRequestDispatcher(path).forward(request, response);
}
add.jsp頁面
<form action="AddressServlet?method=add" method="post">
Name:<input type="text" name="name"/><br>
Street:<input type="text" name="street"/><br>
City:<input type="text" name="city"/><br>
State:<input type="text" name="state"/><br>
Zip:<input type="text" name="zip"/><br>
<input type="submit" name="add"/><br>
</form>
edit.jsp頁面
//獲取request中的address對象
<% Address address = (Address)request.getAttribute("address"); %>
<form action="AddressServlet?method=edit" method="post">
<input type="hidden" name="id"value="<%=address.getId()%>"><br>
Name:<input type="text" name="name" value="<%=address.getName()%>"><br>
Street:<input type="text" name="street" value="<%=address.getStreet()%>"><br>
City:<input type="text" name="city" value="<%=address.getCity()%>"><br>
State:<input type="text" name="state" value="<%=address.getState()%>"><br>
Zip:<input type="text" name="zip" value="<%=address.getZip()%>"><br>
<input type="submit" name="Edit" value="編輯"/><br>
</form>
list頁面
<body><br>
<table border="1">
<tr>
<td>Name</td>
<td>Street</td>
<td>City</td>
<td>State</td>
<td>Zip</td>
<td><center>Options</center></td>
<tr>
<%
List<Address> list = (List<Address>)request.getAttribute("list");
for(Address a :list){
%>
<tr>
<td><%=a.getName()%></td>
<td><%=a.getStreet() %></td>
<td> <%=a.getCity()%></td>
<td><%=a.getState()%></td>
<td><%=a.getZip() %></td>
<td>
<a href="AddressServlet?method=delete&id=<%=a.getId() %>">Delete</a>
<a href="AddressServlet?method=toedit&id=<%=a.getId() %>">Edit</a>
</td>
</tr>
<%}%>
</table>
<a href="add.jsp">Add</a>
最後若覺得請求url名字過長，可在index.jsp頁面設置默認跳轉<jsp:forward page="AddressServlet?method=list"></jsp:forward>
主要重點在於增刪改查的邏輯，方便對這些知識掌握不牢的同學進行理解，當然有興趣的同學代可以繼續優化代碼，使之更加符合項目要求的MVC設計思想，增加service以及serviceImp，daoImp等等，以後會出基於ssh三層架構的javaWeb，歡迎批評指正
源代碼下載