SpringMVC--03--前端传数组给后台-编程知识

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文章目录

案例1
- 乘客个人信息
- 方法1：表单提交，以字段数组接收
- 方法2：表单提交，以BeanListModel接收
- 方法3：==将Json对象==序列化成Json字符串提交，以List接收
- - 3.1 List<Map<String,Object>
  - 3.2 List< User>
案例 2：后台接受数组和集合的案例
- 基本user配置
- 场景1： POST提交 -前端传==数组==后台如何接受
- - - ["2021","2022"]
    - 数组 String [ ] 接
    - List< String>接
- 场景2： get提交：前端在URL里面传id1，id2后台如何接受？
- 场景3：前端传==对象集合==后台如何接受？
- 场景4 ：综合情况

案例1

我要在一个表单里同时一次性提交多名乘客的个人信息到SpringMVC，前端HTML和SpringMVC Controller里该如何处理？

乘客个人信息

public class User {private Integer id;private String name;private String pwd;@Overridepublic String toString() {return "User{" +"id=" + id +", name='" + name + '\'' +", pwd='" + pwd + '\'' +'}';}// .......后面还有getter、setter方法，省略了}

方法1：表单提交，以字段数组接收

HTML代码如下：

    <form action="/user/submitUserList_1" method="post">ID:<input type="text" name="id"><br/>Username:<input type="text" name="name"><br/>Password:<input type="text" name="pwd"><br/><br/>ID:<input type="text" name="id"><br/>Username:<input type="text" name="name"><br/>Password:<input type="text" name="pwd"><br/><br/><input type="submit" value="submit"></form>

Java代码如下：

    @RequestMapping(value = "/submitUserList_1", method ={RequestMethod.POST})@ResponseBodypublic String submitUserList_1(HttpServletResponse response,Integer[] id, String[] name, String[] pwd)throws Exception{String result = "";if(id == null || id.length <= 0){ return "No any ID.中文"; }List<User> userList = new ArrayList<User>();for (int i = 0; i < id.length; i++ ) {User user = new User();user.setId(id[i]);user.setName(name[i]);user.setPwd(pwd[i]);userList.add(user);}result = this.showUserList(userList);return result;}

方法2：表单提交，以BeanListModel接收

HTML代码如下：

    <form action="/user/submitUserList_2" method="post">ID:<input type="text" name="users[0].id"><br/>Username:<input type="text" name="users[0].name"><br/>Password:<input type="text" name="users[0].pwd"><br/><br/>ID:<input type="text" name="users[2].id"><br/>Username:<input type="text" name="users[2].name"><br/>Password:<input type="text" name="users[2].pwd"><br/><br/><input type="submit" value="Submit"></form>

除了刚才公用的User类，还要封装一个User的容器类UserModel：

public class UserModel {private List<User> users;public List<User> getUsers() {return users;}public void setUsers(List<User> users) {this.users = users;}public UserModel(List<User> users) {super();this.users = users;}public UserModel() {super();}}

SpringMVC Controller方法：

    @RequestMapping(value = "/submitUserList_2", method ={RequestMethod.POST})@ResponseBodypublic String submitUserList_2(UserModel users)throws Exception{String result = "";List<User> userList = users.getUsers();if(userList == null || userList.size() <= 0){ return "No any ID.中文"; }result = this.showUserList(userList);return result;}

方法3：将Json对象序列化成Json字符串提交，以List接收

HTML代码：

<head><title>submitUserList_3</title><meta http-equiv="content-type" content="text/html; charset=utf-8"><script language="JavaScript" src="/js/jquery.min.js" ></script><script language="JavaScript" src="/js/jquery.json.min.js" ></script><script type="text/javascript" language="JavaScript">function submitUserList_3() {alert("ok");var customerArray = new Array();customerArray.push({id: "1", name: "李四", pwd: "123"});customerArray.push({id: "2", name: "张三", pwd: "332"});$.ajax({url: "/user/submitUserList_3",type: "POST",contentType : 'application/json;charset=utf-8', //设置请求头信息dataType:"json",//data: JSON.stringify(customerArray),    //将Json对象序列化成Json字符串，JSON.stringify()原生态方法data: $.toJSON(customerArray),            //将Json对象序列化成Json字符串，toJSON()需要引用jquery.json.min.jssuccess: function(data){alert(data);},error: function(res){alert(res.responseText);}});}</script>
</head><body><h1>submitUserList_3</h1><input id="submit" type="button" value="Submit" onclick="submitUserList_3();">
</body>

3.1 List<Map<String,Object>

 @RequestMapping("/createOrder")@ResponseBodypublic int createOrder(@RequestBody List<Map<String,Object>> list ){if (list != null && list.size() > 0){result = this.showList(users);return result;}return 0;}

3.2 List< User>

Java代码：

    @RequestMapping(value = "/submitUserList_3", method ={RequestMethod.POST})@ResponseBodypublic String submitUserList_3(@RequestBody List<User> users)throws Exception{String result = "";if(users == null || users.size() <= 0){ return "No any ID.中文"; }result = this.showUserList(users);return result;}

案例 2：后台接受数组和集合的案例

基本user配置

首先我们模拟创建一个user的实例

@Data
public class User {private String id;private String name;private Integer age;}

创建一个公共的返回值的Result类

import lombok.Data;@Data
public class Result<T> {private static final long serialVersionUID = 1L;private Integer code;private String msg;private T data;public static Result fail() {Result Result = new Result();Result.setCode(1);Result.setMsg("服务器错误！！！");return Result;}public static Result fail(String msg) {Result Result = new Result();Result.setCode(1);Result.setMsg(msg);return Result;}public static <T> Result success(T data) {Result Result = new Result();Result.setCode(0);Result.setData(data);return Result;}public static Result success() {Result Result = new Result();Result.setCode(0);Result.setMsg("操作成功！");Result.setData("success");return Result;}}

场景1： POST提交 -前端传数组后台如何接受

[“2021”,“2022”]

var ids = ['2021','2022'];
$.ajax({type : 'POST',url: 'course/delete',contentType : "application/json" ,data: JSON.stringify(ids),success : function(data) {}
});

数组 String [ ] 接

@RequestMapping(value = "/delete", method = {RequestMethod.POST})
@ResponseBody
public void delete(@RequestBody String[] id) {for (String string : id) {System.out.println(string);}
}

List< String>接

 @PostMapping("/saveUserIds")public Result saveStrings(@RequestBody List<String> list) {logger.info("传入的参数是{}",list);//模拟逻辑层做一个入参校验if (CollectionUtils.isEmpty(list)){return Result.fail();}return Result.success();}

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场景2： get提交：前端在URL里面传id1，id2后台如何接受？

@RequestParam或@PathVariable
前台可以直接URL中通过id1，id2的方式入参，后台直接通过数组或List的的方式来接收，作为动态sql的入参，使用动态sql的foreach语法：

    @ApiOperation("通过alarmId删除报警记录")@DeleteMapping("/delete/{alarmIds}")public Result delete(@ApiParam("报警记录id") @PathVariable Long[] alarmIds){return alarmRecordService.deleteAlarmRecordByIds(alarmIds);}

场景3：前端传对象集合后台如何接受？

[{"id":"1","name":"辰兮","age":"22"},{"id":"2","name":"辰兮要努力","age":"23"}
]

   /*** 前端传对象集合 后端用集合接* @param userList* @return*/@PostMapping("/saveList")public Result saveUserList(@RequestBody List<User> userList) {logger.info("传入的参数是{}",userList);//模拟逻辑层做一个入参校验if (CollectionUtils.isEmpty(userList)){return Result.fail();}return Result.success();

在这里插入图片描述

场景4 ：综合情况

就是前端除了传一个集合外，还要传一个字符串或者数字等属性

入参案例如下

{"userList":[{"id ":"1","name":"辰兮","age":"22"},{"id":"2","name":"辰兮要努力","age":"23"}],"open":1
}

再创建一个对象接受

/*** @program: demo* @description: 用户对象接受类*/
@Data
public class UserVo {private List<User> userList;private Integer open;
}

/*** @program: demo* @description: 前后端传值交互案例*/
@RestController
@RequestMapping("/user")
public class UserController {//打印日志private static final Logger logger = LoggerFactory.getLogger(UserController.class);/*** 业务场景：前端传一个数组➕一个字符串或者数字等* @param userVo* @return*/@PostMapping("/saveUserVo")public Result saveUserVoList(@RequestBody UserVo userVo) {logger.info("传入的参数是{}",userVo);return Result.success();}
}