Rest风格CRUD-CFANZ编程社区

文章目录

系列文章目录
一、rest-query
二、rest-add
三、rest-update
四、rest-delete

一、准备工作

1.创建springmvc-crud.xml文件，配置好扫描包，引入连接数据库的config.properties文件，创建c3p0数据源对象，配置好连接信息以及JdbcTemplate对象以及视图解析器。

<context:component-scan base-package="edu.csust.crud"></context:component-scan>

    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/content/crud/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

    <context:property-placeholder location="classpath:META-INF/config.properties"></context:property-placeholder>

    <!--    创建c3p0数据源对象-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <!--jdbc连接信息-->
        <property name="jdbcUrl" value="${jdbcUrl}"/>
        <property name="driverClass" value="${driverClass}"/>
        <property name="user" value="${user}"/>
        <property name="password" value="${password}"/>

        <!--数据库连接池配置参数-->
        <property name="initialPoolSize" value="${initialPoolSize}"/>
        <property name="minPoolSize" value="${minPoolSize}"/>
        <property name="maxPoolSize" value="${maxPoolSize}"/>
        <property name="acquireIncrement" value="${acquireIncrement}"/>
        <property name="maxStatements" value="${maxStatements}"/>
        <property name="maxStatementsPerConnection" value="${maxStatementsPerConnection}"/>
    </bean>
    <!--    创建JDBCTemplate对象-->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

2.在web.xml文件中引入springmvc-crud.xml文件

<servlet>
     <servlet-name>springmvc</servlet-name>
     <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
     <init-param>
        <!--导入其他文件：指定加载的xml文件路径-->
        <!--classpath:/abc.xml 在当前项目中的classes目录下查找-->
        <!--classpath*:/abc.xml 在当前项目中以及依赖jar中的classes目录下查找-->
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:/META-INF/springmvc-crud.xml</param-value>
        <!--<param-value>classpath:/META-INF/springmvc.xml</param-value>-->

        </init-param>
        <load-on-startup>1</load-on-startup>
     </servlet>
     <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
     </servlet-mapping>

3.创建Employee和Department两个类

package edu.csust.crud.model;

public class Department {
    private Integer did;
    private String departmentName;

    public Department() {
    }

    public Department(Integer did, String departmentName) {
        this.did = did;
        this.departmentName = departmentName;
    }

    public Integer getDid() {
        return did;
    }

    public void setDid(Integer did) {
        this.did = did;
    }

    public String getDepartmentName() {
        return departmentName;
    }

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

    @Override
    public String toString() {
        return "Department{" +
                "did=" + did +
                ", departmentName='" + departmentName + '\'' +
                '}';
    }
}

package edu.csust.crud.model;
public class Employee {
    private Integer eid;
    private String lastName;
    private String email;
    private Integer gender;
    private Department department;

    public Employee() {
    }

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

    public Integer getEid() {
        return eid;
    }

    public void setEid(Integer eid) {
        this.eid = eid;
    }

    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{" +
                "eid=" + eid +
                ", lastName='" + lastName + '\'' +
                ", email='" + email + '\'' +
                ", gender=" + gender +
                ", department=" + department +
                '}';
    }
}

一、获取员工列表

1.添加表格入口<a href="emp" >员工管理</a>

2.书写前端table表格

<h3>员工管理</h3><br>
<a href="emp">添加</a>
<table>
  <tr>
    <th>ID</th>
    <th>名称</th>
    <th>邮箱</th>
    <th>性别</th>
    <th>部门</th>
    <th>操作</th>
  </tr>
  <c:forEach items="${emps}" var="emp">
    <tr>
      <td>${emp.eid}</td>
      <td>${emp.lastName}</td>
      <td>${emp.email}</td>
      <td>${emp.gender==1?"男":"女"}</td>
      <td>${emp.department.departmentName}</td>

      <td>
        <a href="emp/${emp.eid}">编辑</a>
        <a href="emp/${emp.eid}" class="delete">删除</a>
      </td>
    </tr>
  </c:forEach>

3.当点击入口时，获取到所有的员工列表跳转到员工管理页面，所以到层获取到所有员工信息，注意@Repository和注入JdbcTemplate，加上@Autowire

@Autowired
    private JdbcTemplate jdbcTemplate;
    /*
    查询所有员工列表
     */

    public List<Employee> getEmps(){
        String sql="select eid,lastName,email,gender,d.did did,departmentName " +
                "from employees e,department d where e.did=d.did";
        List<Employee> list=jdbcTemplate.query(sql, new RowMapper<Employee>(){
            @Override
            public Employee mapRow(ResultSet rs, int i) throws SQLException {
                Department department=new Department(rs.getInt("did"),rs.getString("departmentName"));
                Employee emp=new Employee(rs.getInt("eid"),rs.getString("lastName"),rs.getString("email"),rs.getInt("gender"),department);
                return emp;
            }
        });
        return list;
    }

5.走控制器跳转到员工列表页面

//获取所有员工列表
	@RequestMapping(value="emps",method= RequestMethod.GET)
	public String getEmps(Map<String,Object> map){
		List<Employee> list=employeeDao.getEmps();
		map.put("emps",list);
		return "index";

	}

二、添加员工

1.在跳转到添加员工页面之前，首先获取到所有部门信息回显在所要提交的表单中，然后在addemp.jsp页面写好form表单中要提交的信息。

DepartmentDao：

@Autowired
    private JdbcTemplate jdbcTemplate;
    /*
    查询所有部门
     */

    public List<Department> getDepts(){
        String sql="select did,departmentName from department";
        List<Department> list=jdbcTemplate.query(sql, new RowMapper<Department>(){
            @Override
            public Department mapRow(ResultSet rs, int i) throws SQLException {
                Department dep=new Department(rs.getInt("did"),rs.getString("departmentName"));
                return dep;
            }
        });
        return list;
    }

<h3>添加员工</h3>
    <%--modelAttribute是需要从request中获取指定key--%>
    <%--path属性会从modelAttribute中对应提交和显示--%>
    <form:form action="${pageContext.request.contextPath}/emp" method="post" modelAttribute="employee">
        <c:if test="${employee.eid!=null}">
            <form:hidden path="eid"/>
        <%--rest隐藏域--%>
            <input type="hidden" name="_method" value="PUT">
        </c:if>
    LastName:<form:input path="lastName" /><br>
    Email:<form:input path="email" /><br>
        <%
            Map<String,String> gender=new HashMap<>();
			gender.put("0","女");
			gender.put("1","男");
			request.setAttribute("gender",gender);
        %>
    性别:<form:radiobuttons path="gender" items="${gender}"/><br>
        部门:<form:select path="department.did" items="${depts }" itemValue="did" itemLabel="departmentName"></form:select><br>
        <input type="submit" value="提交">
    </form:form>

2.经过控制器跳转到添加员工页面

/**
	 * 获取所有部门列表
	 * @param map 需要将部门信息返回到前端
	 * @return
	 */
	@RequestMapping(value="emp",method= RequestMethod.GET)
	public String getdepts(Map<String,Object> map){
		List<Department> list=departmentDao.getDepts();
		map.put("depts",list);
		//前端form标签中指定的modelAttribute属性需要在request存在
		map.put("employee",new Employee());
		return "addemp";
	}

Rest风格CRUD_bc

3.输入信息点击提交后经过控制器method="POST"，调用dao将数据插入数据库

//添加员工
	@RequestMapping(value="emp",method= RequestMethod.POST)
	public String addEmps(Employee emp){
		employeeDao.saveEmps(emp);
		return "redirect:/emps";

	}

EmployeeDao

/*
        添加员工
     */

    public int saveEmps(Employee emp){
        String sql="insert into employees(lastName,email,gender,did) values(?,?,?,?)";
        int i=jdbcTemplate.update(sql, emp.getLastName(),emp.getEmail(),emp.getGender(),emp.getDepartment().getDid());
        return i;

    }

三、修改员工

1.点击编辑后将员工eid传到控制器，获取到eid为该对象的员工对象，传回到addemp.jsp前端页面进行显示

<a href="emp/${emp.eid}">编辑</a>

EmployeeControl

//修改员工：进入修改页面
	@RequestMapping(value="emp/{eid}",method= RequestMethod.GET)
	public String editempin(@PathVariable Integer eid,Map<String,Object> map){
		List<Department> list=departmentDao.getDepts();
		map.put("depts",list);
		Employee employee=employeeDao.getEmpById(eid);
		map.put("employee",employee);
		return "addemp";

	}

EmployeeDao

//根据员工id获取员工对象
    public Employee getEmpById(Integer eid){
        String sql="select eid,lastName,email,gender,d.did did,departmentName " +
                "from employees e,department d where e.did=d.did and eid=?";
        Employee employee=jdbcTemplate.queryForObject(sql, new Object[]{eid}, new RowMapper<Employee>() {
            @Override
            public Employee mapRow(ResultSet rs, int i) throws SQLException {
                Department department=new Department(rs.getInt("did"),rs.getString("departmentName"));
                Employee emp=new Employee(rs.getInt("eid"),rs.getString("lastName"),
                        rs.getString("email"),rs.getInt("gender"),department);
                return emp;
            }
        });
            return employee;
    }

2.此处修改页面和添加页面整合为一个页面，但是添加员工的时候没有eid传过去，但是修改信息的时候，要传eid过去，所以可以使用c:if来区分是添加还是修改。之前笔记有提到使用哪种请求方式。

<c:if test="${employee.eid!=null}">
    <form:hidden path="eid"/>
    <%--rest隐藏域--%>
    <input type="hidden" name="_method" value="PUT">
</c:if>

3.将eid作为隐藏域提交过去之后，根据eid修改员工信息。

EmployeeControl

//修改员工
	@RequestMapping(value="emp",method= RequestMethod.PUT)
	public String editemp(Employee employee){
		employeeDao.editEmp(employee);
		return "redirect:/emps";
	}

EmployeeDao

//修改员工
    public int editEmp(Employee emp){
        String sql="update employees set lastName=?,email=?,gender=?,did=? where eid=?";
        int i=jdbcTemplate.update(sql,emp.getLastName(),emp.getEmail(),emp.getGender(),emp.getDepartment().getDid(),emp.getEid());
        return i;
    }

四、删除员工

1.点击删除之后，把eid传过去，根据eid删除员工对象。

<a href="emp/${emp.eid}" class="delete">删除</a>

EmployeeControl

@RequestMapping(value = "emp/{eid}",method=RequestMethod.DELETE)
	public String deleteemp(@PathVariable Integer eid){
		employeeDao.deleteEmp(eid);
		return "redirect:/emps";
	}

EmoloyeeDao

public int deleteEmp(Integer eid){
        String sql="delete from employees where eid=?";
        int i=jdbcTemplate.update(sql,eid);
        return i;
    }

注意：点击删除之后由于表单action为添加页面路径，所以需要书写js，让默认事件不要触发。

<script>
      $(function(){
        $(".delete").click(function(){
          var href=$(this).attr("href");
          $("form").attr("action",href).submit();
          return false;//不会再执行默认事件
        });
      })
</script>

且需要表单再添加一个隐藏域，使得method=request.DELETE

<form action="" method="post">
  <input type="hidden" name="_method" value="DELETE">
</form>

由于静态资源会被springmvc拦截所以要配置静态资源,有以下两种方式

<!--静态资源处理方式一:非银蛇url交给default servlet处理-->
    <mvc:default-servlet-handler/>
    <mvc:annotation-driven></mvc:annotation-driven>

    <!--静态资源处理方式二：指定路径查找对应的的静态资源-->
    <!--<mvc:resources mapping="/css/**" location="/css/"></mvc:resources>-->
    <!--<mvc:resources mapping="/js/**" location="/js/"></mvc:resources>-->
    <!--<mvc:resources mapping="/image/**" location="/image/**"></mvc:resources>-->
    <!--<mvc:annotation-driven></mvc:annotation-driven>-->