Servlet（六）：连接数据库，完整的CRUD
2024-10-17 21:22:33
Servlet的知识点大致讲完了，今天补充下与之相关的一些小知识，然后做一个完整的小例子。
一、MVC设计模式
1、MVC设计模式是什么？
在了解MVC之前，先聊聊Model1、Model2开发模式。
Model1开发模式中，使用jsp页面嵌套一些java代码、代码块，既处理请求，又处理数据，将java代码和html代码高度耦合在一起，对于后期的维护和拓展非常不便，这就是Model1开发模式。
Model2开发模式，引入了分层思想，即MVC模式，将代码进行了分层，降低了耦合度，方便后期的维护和扩展。
MVC模式，其中M是Model的缩写，表示模型，在应用中包含业务处理层和数据访问层。数据访问层主要是对数据库的一些操作的封装。业务处理层应用JavaBean构建， JavaBean主要是用作将从View层获取的数据和数据库的数据进行桥接。
V是View的缩写，表示视图，视图提供了可交互的用户界面，向用户显示模型数据，通常使用jsp和HTML搭建。
C是Controller的缩写，表示控制层，负责调度，是模型和视图的桥梁。
2、为什么要用MVC设计模式？
一是程序耦合度较低，方便修改和维护；二是可扩展性高，方便后期的业务扩展；三是可重用性高，可以重复使用已有的控制层，减少重复代码。
二、完整的CRUD
1、新建一个Maven项目，建好目录结构
项目结构使用了上面提到的MVC分层结构，如下图所示
2、配置web.xml和pom.xml文件
web.xml文件是配置servlet的，pom.xml是配置所需要的jar包。
<servlet>
<servlet-name>servlet</servlet-name>
<servlet-class>web.EmployeeServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>servlet</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.8</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
</dependencies>
3、连接数据库
先建库，再建表，然后插入原始数据。
CREATE TABLE employee(
id varchar(36) NOT NULL,
name varchar(50),
gender varchar(4),
birthday DATE,
email varchar(20),
salary varchar(20),
remark varchar(200),
PRIMARY KEY (`id`)
)ENGINE=InnoDB DEFAULT CHARSET=utf8;
insert into employee values ('5476cbc52c084d56a8d2492a372450a3','小川94','男','2000-05-25','1340059045@qq.com','','无');
编写DBUtil类，连接数据库
/**
* 管理数据库连接
* @author 小川94
* @date 2018年6月11日
*/
public class DBUtil { private static String user ="";
private static String password = "";
private static String url = "";
private static String driver = "";
private static Connection conn = null; /**
* 获取数据库连接
* @return Connection
*/
public static Connection getConnection(){
try{
// 读取配置文件
user = ConfigUtil.getConfigValue("jdbc.user");
password = ConfigUtil.getConfigValue("jdbc.password");
url = ConfigUtil.getConfigValue("jdbc.jdbcUrl");
driver = ConfigUtil.getConfigValue("jdbc.driverClass");
// 加载驱动
Class.forName(driver);
conn = DriverManager.getConnection(url, user, password);
}catch(Exception e){
System.out.println("数据库连接异常");
e.printStackTrace();
}
return conn;
} /**
* 关闭数据库连接
* @param conn
*/
public static void closeConnection(Connection conn){
if(conn != null){
try{
conn.close();
}catch(SQLException e){
System.out.println("数据库关闭异常");
e.printStackTrace();
}
}
} }
其中使用了读取配置文件的ConfigUtil类
/**
* 读取配置文件
* @author 小川94
* @date 2018年6月11日
*/
public class ConfigUtil { public static String getConfigValue(String tagName) {
String tagValue = null;
Properties prop = new Properties();
try {
ClassLoader classLoader = ConfigUtil.class.getClassLoader();
// 读取配置文件dbconfig.properties
InputStream in = classLoader.getResourceAsStream("dbconfig.properties");
prop.load(in); // 加载属性列表
Iterator<String> it = prop.stringPropertyNames().iterator();
while (it.hasNext()) {
if (it.next().equals(tagName)) {
tagValue = prop.getProperty(tagName);
}
}
in.close();
} catch (Exception e) {
e.printStackTrace();
}
return tagValue;
} }
4、编写实体类
/**
* 实体类
* @author 小川94
* @date 2018年6月11日
*/
public class Employee { private String id; // 主键
private String name; // 姓名
private String gender; // 性别
private String email; // 邮箱
private String salary; // 薪水
private String remark; // 备注
private Date birthday; // 出生日期 public Employee(){ } public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getSalary() {
return salary;
}
public void setSalary(String salary) {
this.salary = salary;
}
public String getRemark() {
return remark;
}
public void setRemark(String remark) {
this.remark = remark;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
} /**
* 重写toString方法，方便junit测试
*/
@Override
public String toString() {
return "Employee [id=" + id + ", name=" + name + ", gender=" + gender + ", birthday=" + birthday
+", salary=" + salary + ", email=" + email + ", remark=" + remark + "]";
} }
5、查询数据
查询数据功能，一是查询出所有数据，二是需要考虑页面的查询条件，需要两者结合考虑。
控制层使用了反射机制，使用一个Servlet处理多个请求，减少代码重复。
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 获取请求的URI地址信息
String url = request.getRequestURI();
// 截取其中的方法名
String methodName = url.substring(url.lastIndexOf("/")+1, url.lastIndexOf("."));
Method method = null;
try {
// 使用反射机制获取在本类中声明了的方法
method = getClass().getDeclaredMethod(methodName, HttpServletRequest.class, HttpServletResponse.class);
// 执行方法
method.invoke(this, request, response);
} catch (Exception e) {
throw new RuntimeException("调用方法出错！");
}
}
/**
* 查询employee表中的所有数据
* @return List<Employee> 包含所有员工信息的list
*/
public List<Employee> queryAllEmployee(String name, String salary, String salary2) {
Connection conn = null;
List<Employee> employees = new ArrayList<Employee>();
try{
// 连接数据库
conn = DBUtil.getConnection();
if (StringUtil.isEmpty(conn)) {
throw new Exception("数据库连接失败");
}
// 编写sql语句
String sql = "SELECT * FROM EMPLOYEE";
String str = "";
if(StringUtil.isNotEmpty(name) || StringUtil.isNotEmpty(salary) || StringUtil.isNotEmpty(salary2)){
if(StringUtil.isNotEmpty(name)){
str = " WHERE NAME LIKE '%"+name+"%'";
}
if(StringUtil.isNotEmpty(salary)){
if(str.length() == 0){
str = " WHERE SALARY > " + salary;
}else{
str = str + " AND SALARY > " + salary;
}
}
if(StringUtil.isNotEmpty(salary2)){
if(str.length() == 0){
str = " WHERE SALARY < " + salary2;
}else{
str = str + " AND SALARY < " + salary2;
}
}
}
// 创建一个 PreparedStatement 对象，初始化sql语句
PreparedStatement ps = conn.prepareStatement(sql+str);
// 获取执行sql语句后的结果集
ResultSet rs = ps.executeQuery();
Employee emp = null;
// 遍历结果集，添加到list中
while (rs.next()) {
emp = new Employee();
emp.setId(rs.getString("id"));
emp.setName(rs.getString("name"));
emp.setGender(rs.getString("gender"));
emp.setEmail(rs.getString("email"));
emp.setBirthday(rs.getDate("birthday"));
emp.setRemark(rs.getString("remark"));
emp.setSalary(rs.getString("salary"));
employees.add(emp);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
// 关闭数据库连接
if (StringUtil.isNotEmpty(conn)) {
DBUtil.closeConnection(conn);
}
}
return employees;
}
编写控制层代码
private void queryEmp(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
EmployeeDao dao = new EmployeeDao();
request.setCharacterEncoding("utf-8");
String name = request.getParameter("name");
String salary = request.getParameter("salary");
String salary2 = request.getParameter("salary2");
List<Employee> employees = dao.queryAllEmployee(name, salary, salary2);
request.setAttribute("employees", employees);
request.getRequestDispatcher("queryList.jsp").forward(request, response);
}
6、新增数据
本质是提交表单数据到后台，通过Model层处理数据。
/**
* 新增员工信息
* @param emp
*/
public int addEmployee(Employee emp){
if(StringUtil.isEmpty(emp)){
throw new RuntimeException("参数为空！");
}
Connection conn = null;
int result = 0;
try{
conn = DBUtil.getConnection();
if(StringUtil.isEmpty(conn)){
throw new Exception("数据库连接失败！");
}
String sql = "INSERT INTO EMPLOYEE VALUES (?,?,?,?,?,?,?) ";
PreparedStatement ps = conn.prepareStatement(sql);
ps.setString(1, StringUtil.getUUID());
ps.setString(2, emp.getName());
ps.setString(3, emp.getGender());
ps.setDate(4, emp.getBirthday());
ps.setString(5, emp.getEmail());
ps.setString(6, emp.getSalary());
ps.setString(7, emp.getRemark());
result = ps.executeUpdate();
}catch(Exception e){
e.printStackTrace();
} finally {
// 关闭数据库连接
if (StringUtil.isNotEmpty(conn)) {
DBUtil.closeConnection(conn);
}
}
return result;
}
/**
* 新增（修改）员工信息，根据id是否为空判断新增操作、修改操作
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
private void addEmp(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
EmployeeDao dao = new EmployeeDao();
request.setCharacterEncoding("utf-8");
Employee emp = new Employee();
String id = request.getParameter("id");
if (StringUtil.isEmpty(id) || "null".equals(id)) {
try {
emp.setId(StringUtil.getUUID());
emp.setName(request.getParameter("name"));
emp.setGender(request.getParameter("gender"));
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
java.util.Date date = sdf.parse(request.getParameter("birthday"));
java.sql.Date birthday = new java.sql.Date(date.getTime());
emp.setBirthday(birthday);
emp.setEmail(request.getParameter("email"));
emp.setSalary(request.getParameter("salary"));
emp.setRemark(request.getParameter("remark"));
} catch (Exception e) {
e.printStackTrace();
}
dao.addEmployee(emp);
response.sendRedirect("queryList.jsp");
} else {
modifyEmpInfo(request, response);
}
}
7、修改数据
修改数据，我们共用了新增数据的jsp页面，使用了js方法来控制页面的数据展示和可修改性，同时后台需要对新增和修改的数据处理逻辑拆分。
/**
* 根据员工信息id来修改相关内容
* @param id
* @return
*/
public boolean modifyEmployeeById(Employee emp){
if(StringUtil.isEmpty(emp)){
throw new RuntimeException("参数为空！");
}
Connection conn = null;
boolean flag = false;
try{
conn = DBUtil.getConnection();
if(StringUtil.isEmpty(conn)){
throw new Exception("数据库连接失败！");
}
String sql = "UPDATE EMPLOYEE SET EMAIL=? , SALARY=? , REMARK=? WHERE ID=? ";
PreparedStatement ps = conn.prepareStatement(sql);
ps.setString(1, emp.getEmail());
ps.setString(2, emp.getSalary());
ps.setString(3, emp.getRemark());
ps.setString(4, emp.getId());
int result = ps.executeUpdate();
if (result == 1) {
flag = true;
}
} catch(Exception e) {
e.printStackTrace();
} finally {
// 关闭数据库连接
if (StringUtil.isNotEmpty(conn)) {
DBUtil.closeConnection(conn);
}
}
return flag;
}
编写控制层代码
private void modifyEmpInfo(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
request.setCharacterEncoding("utf-8");
EmployeeDao dao = new EmployeeDao();
Employee emp = new Employee();
try{
emp.setId(request.getParameter("id"));
emp.setName(request.getParameter("name"));
emp.setGender(request.getParameter("gender"));
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
java.util.Date date = sdf.parse(request.getParameter("birthday"));
java.sql.Date birthday = new java.sql.Date(date.getTime());
emp.setBirthday(birthday);
emp.setEmail(request.getParameter("email"));
emp.setSalary(request.getParameter("salary"));
emp.setRemark(request.getParameter("remark"));
}catch(Exception e){
e.printStackTrace();
}
boolean flag = dao.modifyEmployeeById(emp);
if(!flag){
request.setAttribute("msg", "修改员工信息失败！");
request.getRequestDispatcher("error.jsp").forward(request, response);
}else{
response.sendRedirect("queryList.jsp");
}
}
8、删除数据
删除数据，我们需要拿到所要删除数据的id。
/**
* 根据员工信息的id删除数据
* @param id
* @return
*/
public boolean deleteEmployeeById(String id){
if(StringUtil.isEmpty(id)){
throw new RuntimeException("参数为空！");
}
Connection conn = null;
boolean flag = false;
try{
conn = DBUtil.getConnection();
if(StringUtil.isEmpty(conn)){
throw new Exception("连接数据库失败！");
}
String sql = "DELETE FROM EMPLOYEE WHERE ID = ?";
PreparedStatement ps = conn.prepareStatement(sql);
ps.setString(1, id);
int result = ps.executeUpdate();
if(result == 1){
flag = true;
}
} catch (Exception e) {
e.printStackTrace();
} finally {
// 关闭数据库连接
if (StringUtil.isNotEmpty(conn)) {
DBUtil.closeConnection(conn);
}
}
return flag;
}
编写控制层代码
private void deleteEmp(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
EmployeeDao dao = new EmployeeDao();
request.setCharacterEncoding("utf-8");
String id = request.getParameter("id");
boolean flag = dao.deleteEmployeeById(id);
if(!flag){
request.setAttribute("msg", "删除员工信息失败！");
request.getRequestDispatcher("error.jsp").forward(request, response);
}else{
request.getRequestDispatcher("queryList.jsp").forward(request, response);
}
}
9、查看数据
查看数据的本质是将数据查询出来，回显到页面。
/**
* 根据员工信息id查询完整员工信息
* @param id
* @return
*/
public Employee queryEmpById(String id) {
if (StringUtil.isEmpty(id)) {
throw new RuntimeException("参数为空！");
}
Connection conn = null;
Employee emp = new Employee();
try {
conn = DBUtil.getConnection();
if (StringUtil.isEmpty(conn)) {
throw new RuntimeException("数据库连接失败！");
}
String sql = "SELECT * FROM EMPLOYEE WHERE ID=?";
PreparedStatement ps = conn.prepareStatement(sql);
ps.setString(1, id);
ResultSet rs = ps.executeQuery();
if(StringUtil.isEmpty(rs)){
throw new RuntimeException("查询信息失败！");
}
while (rs.next()) {
emp.setId(rs.getString("id"));
emp.setName(rs.getString("name"));
emp.setGender(rs.getString("gender"));
emp.setEmail(rs.getString("email"));
emp.setBirthday(rs.getDate("birthday"));
emp.setRemark(rs.getString("remark"));
emp.setSalary(rs.getString("salary"));
}
} catch (Exception e) {
e.printStackTrace();
} finally {
// 关闭数据库连接
if (StringUtil.isNotEmpty(conn)) {
DBUtil.closeConnection(conn);
}
}
return emp;
}
编写控制层代码
private void queryEmpInfo(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
EmployeeDao dao = new EmployeeDao();
request.setCharacterEncoding("utf-8");
String id = request.getParameter("id");
Employee emp = dao.queryEmpById(id);
request.getSession().setAttribute("Emp", emp);
request.getRequestDispatcher("empInfo.jsp").forward(request, response);
}
10、单元测试
使用Junit包，来完成相应的功能方法测试。
public class TestSample extends TestCase {
private long startTime;
private long endTime;
@Before
public void setUp() throws Exception {
this.startTime= System.currentTimeMillis();
System.out.println("=========开始测试===========");
}
@After
public void tearDown() throws Exception {
this.endTime = System.currentTimeMillis();
System.out.println("测试用时："+(endTime-startTime));
System.out.println("=========测试结束===========");
}
/**
* 测试数据库连接
*/
@Test
public void testDBConnection(){
Connection conn = DBUtil.getConnection();
if(StringUtil.isEmpty(conn)){
System.out.println("数据库连接失败！");
}else{
System.out.println("数据库连接成功！");
DBUtil.closeConnection(conn);
}
}
/**
* 测试EmployeeDao中的 queryAllEmployee 方法
*/
@Test
public void testQueryAllEmployee(){
EmployeeDao dao = new EmployeeDao();
List<Employee> list = dao.queryAllEmployee("张","","");
if(StringUtil.isEmpty(list)){
System.out.println("查询员工信息失败");
}else{
for(Employee emp : list){
System.out.println(emp.toString());
}
}
}
/**
* 测试EmployeeDao中的 addEmployee 方法
*/
@Test
public void testAddEmployee(){
EmployeeDao dao = new EmployeeDao();
Employee emp = new Employee();
emp.setId(StringUtil.getUUID());
emp.setName("张三");
emp.setGender("男");
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
try {
java.util.Date d = sdf.parse("1987-09-23");
java.sql.Date birthday = new java.sql.Date(d.getTime());
emp.setBirthday(birthday);
} catch (ParseException e) {
e.printStackTrace();
}
emp.setEmail("152612@qq.com");
emp.setSalary("10500");
emp.setRemark("新入职员工");
int result = dao.addEmployee(emp);
if(result == 1){
System.out.println("新增成功");
}else{
System.out.println("新增失败");
}
}
/**
* 测试EmployeeDao中的 deleteEmployeeById 方法
*/
@Test
public void testDeleteEmployeeById(){
EmployeeDao dao = new EmployeeDao();
String id = "8926a2e7-4cf1-4370-abdd-1141f8f6412d";
boolean flag = dao.deleteEmployeeById(id);
if(!flag){
System.out.println("删除员工信息失败！");
}else{
System.out.println("删除成功！");
}
}
/**
* 测试EmployeeDao中的 queryEmpById 方法
*/
@Test
public void testQueryEmpById(){
String id = "0a100fb2-a619-40b5-a667-dba96fae8b49";
EmployeeDao dao = new EmployeeDao();
Employee emp = dao.queryEmpById(id);
System.out.println(emp.toString());
}
}
11、编写View层
查询页面jsp编写
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="java.util.*,entity.*,dao.*" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>员工信息查询列表</title>
<script type="text/javascript">
function searchList(){
var name = document.getElementById("name").value;
var salary = document.getElementById("salary").value;
var salary2 = document.getElementById("salary2").value;
var url = "queryEmp.do";
var str = "";
if (name || salary || salary2) {
if(name){
str = "?name=" + name + "";
}
if(salary){
if(str.length == 0){
str = "?salary=" + salary + "";
}else{
str = str + "&salary=" + salary + "";
}
}
if(salary2){
if(str.length == 0){
str = "?salary2=" + salary2 + "";
}else{
str = str + "&salary2=" + salary2 + "";
}
}
}
window.location.href = url+str;
} function addEmp(){
window.location.href = "addEmp.jsp";
} function myreset(){
document.getElementById("name").value = "";
document.getElementById("salary").value = "";
document.getElementById("salary2").value = "";
}
</script>
</head>
<body>
<div style="height:100px;">
<div style="">
<div style="float:left;">
<span style="margin-left:150px;">姓名</span>
<%
String name = request.getParameter("name");
if(name == null || name == ""){
name = "";
}
String salary = request.getParameter("salary");
if(salary == null || salary == ""){
salary = "";
}
String salary2 = request.getParameter("salary2");
if(salary2 == null || salary2 == ""){
salary2 = "";
}
%>
<input id="name" style="width:150px;height:20px;" type="text" name="name" value="<%=name %>">
</div>
<div style="float:left;">
<span style="margin-left:50px;">薪水</span>
<input id="salary" style="width:120px;height:20px;" type="text" value="<%=salary %>" name="salary"> 至
<input id="salary2" style="width:120px;height:20px;" type="text" value="<%=salary2 %>" name="salary2">
</div>
</div>
<div style="margin-top:40px;" align="center">
<input style="height:30px;font-size:16px;margin-right:20px;" type="button" onclick="searchList()" value="查询">
<input style="height:30px;font-size:16px;margin-right:20px;" type="button" onclick="myreset()" value="重置">
<input style="height:30px;font-size:16px;" type="button" onclick="addEmp()" value="新增">
</div>
</div>
<div align="center">
<table onload="searchList()" cellpadding="0" cellspacing="0" border="1px black solid">
<thead>
<tr style="height:40px;">
<th style="width:80px;text-align: center;">序号</th>
<th style="width:120px;text-align: center;">姓名</th>
<th style="width:100px;text-align: center;">性别</th>
<th style="width:150px;text-align: center;">出生日期</th>
<th style="width:120px;text-align: center;">薪水</th>
<th style="width:180px;text-align: center;">邮箱</th>
<th style="width:150px;text-align: center;">备注</th>
<th style="width:150px;text-align: center;">操作</th>
</tr>
</thead>
<tbody>
<%
List<Employee> employees = (List<Employee>)request.getAttribute("employees");
if(employees != null){
for(int i=0; i<employees.size(); i++){
Employee e = employees.get(i);
%>
<tr style="height:35px;">
<td style="text-align:center;"><%=i+1 %></td>
<td style="text-align:center;"><a href="queryEmpInfo.do?id=<%=e.getId() %>" style="text-decoration:none;color:blue"><%=e.getName() %></a></td>
<td style="text-align:center;"><%=e.getGender() %></td>
<td style="text-align:center;"><%=e.getBirthday() %></td>
<td style="text-align:center;"><%=e.getSalary() %></td>
<td style="text-align:center;"><%=e.getEmail() %></td>
<td style="text-align:center;"><%=e.getRemark() %></td>
<td style="text-align:center;">
<a href="openModifyEmpInfo.do?id=<%=e.getId() %>" style="text-decoration:none;color:blue">修改</a>
<a href="deleteEmp.do?id=<%=e.getId() %>" style="text-decoration:none;color:blue">删除</a>
</td>
</tr>
<%
}
}
%>
</tbody>
</table>
</div> </body>
</html>
新增（修改）jsp页面编写
<%@page import="jdk.nashorn.internal.runtime.Undefined"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="java.util.*,java.text.*,entity.Employee" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>新增员工信息</title>
</head>
<body onload="myload()"> <%
String id = request.getParameter("id");
Employee emp = (Employee)request.getSession().getAttribute("Emp");
String name = "";
String gender = "";
String birthday = "";
String email = "";
String salary = "";
String remark = "";
if (emp!= null) {
name = emp.getName();
gender = emp.getGender();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
if(emp.getBirthday() != null){
java.sql.Date d = emp.getBirthday();
java.util.Date date = new java.util.Date(d.getTime());
birthday = sdf.format(date);
}
email = emp.getEmail();
salary = emp.getSalary();
remark = emp.getRemark();
}
%> <div style="padding-top: 60px;" align="center">
<form action="addEmp.do?id=<%=id %>" method="post">
<table cellpadding="0" cellspacing="0" border="1px black solid">
<tr style="height:40px;">
<td style="font-size:18px;text-align: right;width:100px;">姓名 </td>
<td style="width:400px;">
<input id="name" style="width:350px;height:20px;margin-left:10px;" type="text" name="name">
</td>
</tr>
<tr style="height:40px;">
<td style="font-size:18px;text-align: right;width:100px;">性别 </td>
<td>
<input id="boy" style="width:30px;height:20px;margin-left:10px;" type="radio" name="gender" value="男">男
<input id="gril" style="width:30px;height:20px;margin-left:10px;" type="radio" name="gender" value="女">女
</td>
</tr>
<tr style="height:40px;">
<td style="font-size:18px;text-align: right;width:100px;">出生日期 </td>
<td>
<input id="birthday" style="height:20px;margin-left:10px;" type="date" name="birthday">
</td>
</tr>
<tr style="height:40px;">
<td style="font-size:18px;text-align: right;width:100px;">邮箱 </td>
<td>
<input id="email" style="width:350px;height:20px;margin-left:10px;" type="text" name="email">
</td>
</tr>
<tr style="height:40px;">
<td style="font-size:18px;text-align: right;width:100px;">薪水 </td>
<td>
<input id="salary" style="width:350px;height:20px;margin-left:10px;" type="text" name="salary">
</td>
</tr>
<tr style="height:40px;">
<td style="font-size:18px;text-align: right;width:100px;">备注 </td>
<td>
<textarea id="remark" style="margin:10px;" rows="6" cols="47" name="remark"></textarea>
</td>
</tr>
</table>
<div style="margin:20px;">
<input style="height:30px;font-size:16px;margin-right:20px;" type="submit" value="提交"/>
<input style="height:30px;font-size:16px;" type="reset" value="重置"/>
</div>
</form>
</div> <script type="text/javascript">
var idstr = "<%=id %>";
function myload() {
if (idstr != null && idstr != undefined && idstr != "null") {
document.getElementById("name").value = "<%=name %>";
var gender = "<%=gender %>";
if(gender == "男"){
document.getElementById("boy").checked = true;
document.getElementById("girl").disabled = "disabled";
} else {
document.getElementById("gril").checked = true;
document.getElementById("boy").disabled = "disabled";
}
document.getElementById("birthday").value = "<%=birthday %>";
document.getElementById("email").value = "<%=email %>";
document.getElementById("salary").value = "<%=salary %>";
document.getElementById("remark").value = "<%=remark %>";
// 设置只读
document.getElementById("name").readOnly = true;
document.getElementById("gril").readOnly = true;
document.getElementById("birthday").readOnly = true;
} else {
document.getElementById("name").readOnly = false;
document.getElementById("boy").readOnly = false;
document.getElementById("gril").readOnly = false;
document.getElementById("birthday").readOnly = false;
}
}
</script> </body>
</html>
查看信息jsp页面编写
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="entity.Employee" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>员工信息</title>
</head>
<body> <jsp:useBean id="Emp" class="entity.Employee" scope="session"></jsp:useBean>
<div style="padding-top: 60px;" align="center">
<form>
<h4>员工信息</h4>
<table cellpadding="0" cellspacing="0" border="1px black solid">
<tr style="height:40px;">
<td style="font-size:18px;text-align: right;width:100px;">姓名 </td>
<td style="width:300px;">
<jsp:getProperty property="name" name="Emp"/>
</td>
</tr>
<tr style="height:40px;">
<td style="font-size:18px;text-align: right;width:100px;">性别 </td>
<td style="width:300px;">
<jsp:getProperty property="gender" name="Emp"/>
</td>
</tr>
<tr style="height:40px;">
<td style="font-size:18px;text-align: right;width:100px;">出生日期 </td>
<td style="width:300px;">
<jsp:getProperty property="birthday" name="Emp"/>
</td>
</tr>
<tr style="height:40px;">
<td style="font-size:18px;text-align: right;width:100px;">邮箱 </td>
<td style="width:300px;">
<jsp:getProperty property="email" name="Emp"/>
</td>
</tr>
<tr style="height:40px;">
<td style="font-size:18px;text-align: right;width:100px;">薪水 </td>
<td style="width:300px;">
<jsp:getProperty property="salary" name="Emp"/>
</td>
</tr>
<tr style="height:40px;">
<td style="font-size:18px;text-align: right;width:100px;">备注 </td>
<td style="width:300px;">
<jsp:getProperty property="remark" name="Emp"/>
</td>
</tr>
</table>
<div style="margin:20px;">
<input style="height:30px;font-size:16px;margin-right:20px;" type="button" onclick="history.back()" value="返回"/>
</div>
</form>
</div>
</body>
</html>
错误信息jsp页面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>错误提示信息</title>
</head>
<body>
<h1 style="margin:200px;">:( 您的上一步操作发生了错误！
<br>
错误信息:<%=request.getParameter("msg") %>
</h1> </body>
</html>
三、测试
测试结果如下图所示，对于分页展示数据的问题，下次再单独处理。
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