spring 16-Spring框架Spring MVC方法参数深入

使用int类型进行接收

在Spring MVC里面对于参数的接收也都是按照字符串接收
而后在帮助用户自动进行转型控制

测试方法：

public class EmpAction extends AbstractAction{
	private Logger log = Logger.getLogger(EmpAction.class) ;
    @RequestMapping("remove")
    public ModelAndView remove(int eid){
    	System.out.println("输出的eid结果："+ eid * 2);
    	return null;
    }
}

测试url-1：

http://localhost:8080/springdemo/pages/emp/remove.action?eid=123

输出结果：
输出的eid结果：246

测试url-2：

http://localhost:8080/springdemo/pages/emp/remove.action?eid=liang

如果输入的类型不同，则出现报错，输出结果：
2018-12-07 14:14:36,648 WARN [org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver] - Resolved [org.springframework.web.method.annotation.MethodArgumentTypeMismatchException: Failed to convert value of type 'java.lang.String' to required type 'int'; nested exception is java.lang.NumberFormatException: For input string: "liang"]

设置参数名称

@RequestParam的作用：

可以指定参数名称
如果没有设置参数内容，可自动使用一个默认值来替换

测试方法：

import org.springframework.web.bind.annotation.RequestParam;
public class EmpAction extends AbstractAction{
	private Logger log = Logger.getLogger(EmpAction.class) ;
    @RequestMapping("remove")
    public ModelAndView remove(@RequestParam(value="empno",defaultValue="10") int eid){
    	System.out.println("输出的eid结果："+ eid * 2);
    	return null;
    }
}

测试url-1：

http://localhost:8080/springdemo/pages/emp/remove.action?empno=1121

输出结果：
输出的eid结果：2242

测试url-2：

http://localhost:8080/springdemo/pages/emp/remove.action

输出结果：
输出的eid结果：20

分页处理

测试方法：

public class EmpAction extends AbstractAction{
	private Logger log = Logger.getLogger(EmpAction.class) ;
    @RequestMapping("list") 
    public ModelAndView list(
    		@RequestParam(value = "cp", defaultValue = "1") int currentPage,
    		@RequestParam(value = "ls", defaultValue = "5") int lineSize , 
    		@RequestParam(value = "col", defaultValue = "ename") String column, 
    		@RequestParam(value = "kw", defaultValue = "")  String keyWord) {
    	log.info("*** currentPage = " + currentPage);
    	log.info("*** lineSize = " + lineSize);
    	log.info("*** column = " + column);
    	log.info("*** keyWord = " + keyWord);
    	return null ;
    }
}

测试url-1：

http://localhost:8080/springdemo/pages/emp/list.action

输出结果：
2018-12-07 14:30:02,393 INFO [cn.liang.action.EmpAction] - *** currentPage = 1
2018-12-07 14:30:02,393 INFO [cn.liang.action.EmpAction] - *** lineSize = 5
2018-12-07 14:30:02,393 INFO [cn.liang.action.EmpAction] - *** column = ename
2018-12-07 14:30:02,393 INFO [cn.liang.action.EmpAction] - *** keyWord =

测试url-2：

http://localhost:8080/springdemo/pages/emp/list.action?cp=3&ls=10&col=ename&kw=liang

输出结果：
2018-12-07 14:31:09,188 INFO [cn.liang.action.EmpAction] - *** currentPage = 3
2018-12-07 14:31:09,193 INFO [cn.liang.action.EmpAction] - *** lineSize = 10
2018-12-07 14:31:09,193 INFO [cn.liang.action.EmpAction] - *** column = ename
2018-12-07 14:31:09,193 INFO [cn.liang.action.EmpAction] - *** keyWord = liang

内置对象配置

测试方法：

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class EmpAction extends AbstractAction{
	private Logger log = Logger.getLogger(EmpAction.class) ;
    @RequestMapping("get")
    public ModelAndView get(HttpServletRequest request,int eid,HttpServletResponse response) {
    	HttpSession session = request.getSession();	// 取得Session对象
    	ServletContext application = request.getServletContext() ;
    	log.info("*** contextPath = " + request.getContextPath());
    	log.info("*** sessionId = " + session.getId());
    	log.info("*** realPath = " + application.getRealPath("/")); 
    	try {
    		response.getWriter().println("Hello World !") ;
    	} catch (IOException e) {
    		e.printStackTrace();
    	}
    	return null ; 
    }
}

测试url：

http://localhost:8080/springdemo/pages/emp/get.action?eid=123

输出结果：
2018-12-07 14:34:41,106 INFO [cn.liang.action.EmpAction] - *** contextPath = /springdemo
2018-12-07 14:34:41,106 INFO [cn.liang.action.EmpAction] - *** sessionId = D94C3830438FE3F8D28DD4B28FB0276B
2018-12-07 14:34:41,106 INFO [cn.liang.action.EmpAction] - *** realPath = /Users/liang/Workspaces/MyEclipse 2017 CI/.metadata/.me_tcat85/webapps/springdemo/

参数与VO转换

编写Emp的VO类：

package cn.liang.vo;
import java.io.Serializable;
import java.util.Date;
@SuppressWarnings("serial")
public class Emp implements Serializable{
	private Integer empno ;
	private String ename ;
	private Double sal ;
	private Date hiredate;
	private Dept dept ;
	public Date getHiredate() {
		return hiredate;
	}
	public void setHiredate(Date hiredate) {
		this.hiredate = hiredate;
	}
	public Integer getEmpno() {
		return empno;
	}
	public void setEmpno(Integer empno) {
		this.empno = empno;
	}
	public String getEname() {
		return ename;
	}
	public void setEname(String ename) {
		this.ename = ename;
	}
	public Double getSal() {
		return sal;
	}
	public void setSal(Double sal) {
		this.sal = sal;
	}
	public Dept getDept() {
		return dept;
	}
	public void setDept(Dept dept) {
		this.dept = dept;
	}
	@Override
	public String toString() {
		return "Emp [empno=" + empno + ", ename=" + ename + ", sal=" + sal + ", hiredate=" + hiredate + ", dept=" + dept
				+ "]";
	}
}

编写Dept的VO类：

package cn.liang.vo;
import java.io.Serializable;

@SuppressWarnings("serial")
public class Dept implements Serializable {
	private Integer deptno ;
	private String dname ; 
	public Integer getDeptno() {
		return deptno;
	}

	public void setDeptno(Integer deptno) {
		this.deptno = deptno;
	}

	public String getDname() {
		return dname;
	}

	public void setDname(String dname) {
		this.dname = dname;
	}

	@Override
	public String toString() {
		return "Dept [deptno=" + deptno + ", dname=" + dname + "]";
	}
	
}

由于日期的参数传递需要有一个转换器来控制
转换器是一个公共的配置，所以需要Action去继承一个父类的Action

编写AbstractAction类：

package cn.liang.util.action;
import java.text.SimpleDateFormat;
import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.InitBinder;

public abstract class AbstractAction { 
	@InitBinder	
	public void initBinder(WebDataBinder binder) {	// 方法名称自己随便写
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss") ;
		// 本方法的处理指的是追加有一个自定义的转换编辑器，如果遇见的操作目标类型为java.util.Date类
		// 则使用定义好的SimpleDateFormat类来进行格式化处理，并且允许此参数的内容为空
		binder.registerCustomEditor(java.util.Date.class, new CustomDateEditor(sdf, true));
	} 
}

编写测试程序：

package cn.liang.action;
import org.apache.log4j.Logger;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import cn.liang.util.action.AbstractAction;
import cn.liang.vo.Emp;
@Controller
@RequestMapping("/pages/emp/*") 
public class EmpAction extends AbstractAction{
	private Logger log = Logger.getLogger(EmpAction.class) ;
	@RequestMapping("add")
	public ModelAndView add(Emp emp) {	// 此时作为一个参数，并且没有实例化
		log.info(emp); 
		return null ; 
	}
}

测试url：

http://localhost:8080/springdemo/pages/emp/add.action?empno=100&ename=liang&sal=100.12&hiredate=1999-12-12%2012:23:12&dept.deptno=30&dept.dname=dv

输出结果：
2018-12-07 14:48:37,706 INFO [cn.liang.action.EmpAction] - Emp [empno=100, ename=liang, sal=100.12, hiredate=Sun Dec 12 12:23:12 CST 1999, dept=Dept [deptno=30, dname=dv]]

配置资源文件

Spring MVC针对资源文件可以通过配置的模式实现

编辑三个资源文件

Message.properties：

vo.edit.msg = {0} u4fe1u606fu7f16u8bd1u5b8cu6210uff01

Pages.properties：

emp.add.page=/pages/back/emp/emp_add.jsp

Validations.properties：

emp.add.rules=empno:int|ename:string|sal:double|hiredate:date

配置applicationContext-mvc.xml文件

<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
	<property name="basenames">
		<array>
			<value>Messages</value>
			<value>Pages</value>
			<value>Validations</value>
		</array>
	</property> 
</bean>

在公共类AbstractAction类进行自动注入的配置模式

package cn.liang.util.action;
import java.util.Locale;
import javax.annotation.Resource;
import org.springframework.context.MessageSource;
public abstract class AbstractAction {
	@Resource
	private MessageSource msgSource ;	// 表示此对象直接引用配置好的类对象（根据类型匹配）
	/**
	 * 根据指定的key的信息进行资源数据的读取控制
	 * @param msgKey 表示要读取的资源文件的key的内容
	 * @return 表示资源对应的内容
	 */
	public String getValue(String msgKey,Object ...args) {
		return this.msgSource.getMessage(msgKey, args, Locale.getDefault()) ;
	} 
}

编写测试方法：

package cn.liang.action;
import org.apache.log4j.Logger;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import cn.liang.util.action.AbstractAction;
@Controller
@RequestMapping("/pages/emp/*") 
public class EmpAction extends AbstractAction{
	private Logger log = Logger.getLogger(EmpAction.class) ;
	
	@RequestMapping("info")
	public ModelAndView info() {
		log.info(super.getValue("vo.edit.msg", "雇员"));
		log.info(super.getValue("emp.add.page"));
		log.info(super.getValue("emp.add.rules"));
		return null ;
	}
}

测试url：

http://localhost:8080/springdemo/pages/emp/info.action

输出结果：
2018-12-07 15:20:22,107 INFO [cn.liang.action.EmpAction] - 雇员 信息编译完成！
2018-12-07 15:20:22,110 INFO [cn.liang.action.EmpAction] - /pages/back/emp/emp_add.jsp
2018-12-07 15:20:22,113 INFO [cn.liang.action.EmpAction] - empno:int|ename:string|sal:double|hiredate:date