springmvc运算-基础练手项目(1)-查询操作

1、编辑web.xml ，常规配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://java.sun.com/xml/ns/javaee"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
	id="WebApp_ID" version="2.5">
	<filter>
		<filter-name>HiddenHttpMethodFilter</filter-name>
		<filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>HiddenHttpMethodFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
	<servlet>
		<servlet-name>dispatcherServlet</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
			<!-- 配置 DispatcherServlet 的一个初始化参数: 配置 SpringMVC 配置文件的位置和名称 -->
		<!-- 
			实际上也可以不通过 contextConfigLocation 来配置 SpringMVC 的配置文件, 而使用默认的.
			默认的配置文件为: /WEB-INF/<servlet-name>-servlet.xml
		-->

		<init-param>
			<param-name>contextConfigLocation</param-name>
			<param-value>classpath:springmvc.xml</param-value>
		</init-param>
	
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>dispatcherServlet</servlet-name>
		<!-- 
               第一种：*.action 或者 *.do，访问以.action或*.do结尾 由DispatcherServlet进行解析
               第二种：/，所以访问的地址都由DispatcherServlet进行解析，对于静态文件的解析需要配置不让DispatcherServlet进行解析
               使用此种方式可以实现 RESTful风格的url
               第三种：/*，这样配置不对，使用这种配置，最终要转发到一个jsp页面时，
               仍然会由DispatcherServlet解析jsp地址，不能根据jsp页面找到handler，会报错。
        -->
		<url-pattern>/</url-pattern>
	</servlet-mapping>
</web-app>

2、编辑转发配置文件（springmvc.xml）

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
		http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">

	<!-- 配置自动扫描的包 -->
	<context:component-scan base-package="com.test.springmvc"></context:component-scan>

	<!-- 配置视图解析器 -->
	<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="prefix" value="/WEB-INF/views/"></property>
		<property name="suffix" value=".jsp"></property>
	</bean>

</beans>

3、测试页面

第一步：请求控制器返回查询页面：
浏览器访问链接: http://localhost:8080/springmvc-2/doGetEmps
或者在页面中配置超链接

<body>
<a href="doGetEmps">请求所有雇员信息页面</a>
</body>

第二步：在查询页面中配置了超链接，请求控制器返回查询后的结果
查询页：getEmps.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/fmt" %>

<!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>Insert title here</title>
</head>
<body>

<a href="emps">请求所有雇员信息（超链接属于get请求）</a>

</body>
</html>

本质上，只要一步直接请求好了，但是为了后续增删改的统一，所以拆成2步。

4、结果响应页面

showGetEmps.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!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>Get All</title>
</head>
<body>

	<c:if test="${empty requestScope.employees}">
没有任何员工信息
</c:if>
	<c:if test="${ !empty requestScope.employees }">
		<table border="1" cellpadding="10" cellspacing="0">
			<tr>
				<th>ID</th>
				<th>LastName</th>
				<th>Email</th>
				<th>Gender</th>
				<th>Department</th>
				<th>Edit</th>
				<th>Delete</th>
			</tr>

			<c:forEach items="${requestScope.employees }" var="emp">
			<tr>
			<td>${emp.id}</td>
            <td>${emp.lastName}</td>
            <td>${emp.email}</td>	            
			<td>${emp.gender==0? "Female":"Male"}</td>					
			<td>${emp.department.departmentName}</td>			
			<td><a href="">Edit</a></td>
			<td><a href="">Delete</a></td>			
			</tr>
			</c:forEach>
		</table>
	</c:if>

</body>
</html>

5、编辑控制器

package com.test.springmvc.crud.handlers;

import java.util.Map;

import javax.validation.Valid;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.validation.Errors;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

import com.test.springmvc.crud.dao.DepartmentDao;
import com.test.springmvc.crud.dao.EmployeeDao;
import com.test.springmvc.crud.entities.Employee;



@Controller
public class EmployeeHandler {

	@Autowired
	private EmployeeDao employeeDao;
	
	@Autowired
	private DepartmentDao departmentDao;

	
	//跳转到查看所有雇员信息页
        @RequestMapping("/doGetEmps")
	public String doGetEmps(){
    	return "getEmps";
    }
    
	//查看所有雇员信息,采用默认的get方法，属于crud操作
	@RequestMapping("/emps")
	public String getEmps(Map<String, Object> map){
		map.put("employees", employeeDao.getAll());
		return "showGetEmps";
	}

	
}

6、数据源配置

（1）entity

Employee.java

package com.test.springmvc.crud.entities;

import java.util.Date;

import javax.validation.constraints.Past;

import org.hibernate.validator.constraints.Email;
import org.hibernate.validator.constraints.NotEmpty;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.format.annotation.NumberFormat;

public class Employee {

	private Integer id;
	
	private String lastName;

	private String email;
	//1 male, 0 female
	private Integer gender;
	
	private Department department;
	

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getLastName() {
		return lastName;
	}

	public void setLastName(String lastName) {
		this.lastName = lastName;
	}

	public String getEmail() {
		return email;
	}

	public void setEmail(String email) {
		this.email = email;
	}

	public Integer getGender() {
		return gender;
	}

	public void setGender(Integer gender) {
		this.gender = gender;
	}

	public Department getDepartment() {
		return department;
	}

	public void setDepartment(Department department) {
		this.department = department;
	}

	
	@Override
	public String toString() {
		return "Employee [id=" + id + ", lastName=" + lastName + ", email="
				+ email + ", gender=" + gender + ", department=" + department
				+ "]";
	}

	public Employee(Integer id, String lastName, String email, Integer gender,
			Department department) {
		super();
		this.id = id;
		this.lastName = lastName;
		this.email = email;
		this.gender = gender;
		this.department = department;
	}

	public Employee() {
		// TODO Auto-generated constructor stub
	}
}

Department.java

package com.test.springmvc.crud.entities;

public class Department {

	private Integer id;
	private String departmentName;

	public Department() {
		// TODO Auto-generated constructor stub
	}
	
	public Department(int i, String string) {
		this.id = i;
		this.departmentName = string;
	}

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getDepartmentName() {
		return departmentName;
	}

	public void setDepartmentName(String departmentName) {
		this.departmentName = departmentName;
	}

	@Override
	public String toString() {
		return "Department [id=" + id + ", departmentName=" + departmentName
				+ "]";
	}
	
}

（2）Dao

package com.test.springmvc.crud.dao;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import com.test.springmvc.crud.entities.Department;
import com.test.springmvc.crud.entities.Employee;


@Repository
public class EmployeeDao {

	private static Map<Integer, Employee> employees = null;
	
	@Autowired
	private DepartmentDao departmentDao;
	
	static{
		employees = new HashMap<Integer, Employee>();

		employees.put(1001, new Employee(1001, "E-AA", "[email protected]", 1, new Department(101, "D-AA")));
		employees.put(1002, new Employee(1002, "E-BB", "[email protected]", 1, new Department(102, "D-BB")));
		employees.put(1003, new Employee(1003, "E-CC", "[email protected]", 0, new Department(103, "D-CC")));
		employees.put(1004, new Employee(1004, "E-DD", "[email protected]", 0, new Department(104, "D-DD")));
		employees.put(1005, new Employee(1005, "E-EE", "[email protected]", 1, new Department(105, "D-EE")));
	}
	
	private static Integer initId = 1006;
	
	public void save(Employee employee){
		if(employee.getId() == null){
			employee.setId(initId++);
		}
		
		employee.setDepartment(departmentDao.getDepartment(employee.getDepartment().getId()));
		employees.put(employee.getId(), employee);
	}
	
	public Collection<Employee> getAll(){
		return employees.values();
	}
	
	public Employee get(Integer id){
		return employees.get(id);
	}
	
	public void delete(Integer id){
		employees.remove(id);
	}
}

package com.test.springmvc.crud.dao;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import org.springframework.stereotype.Repository;

import com.test.springmvc.crud.entities.Department;


@Repository
public class DepartmentDao {

	private static Map<Integer, Department> departments = null;
	
	static{
		departments = new HashMap<Integer, Department>();
		
		departments.put(101, new Department(101, "D-AA"));
		departments.put(102, new Department(102, "D-BB"));
		departments.put(103, new Department(103, "D-CC"));
		departments.put(104, new Department(104, "D-DD"));
		departments.put(105, new Department(105, "D-EE"));
	}
	
	public Collection<Department> getDepartments(){
		return departments.values();
	}
	
	public Department getDepartment(Integer id){
		return departments.get(id);
	}
	
}

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