springmvc后台接前台数组，集合，复杂对象

return "redirect:/icProject/index"; 重定向到请求

model.addAttribute("page", page);
return "icProject/index";跳转到页面

1.ajax提交，将数组封装成json,后台用List<Integer>接

2.form提交

方法一：

前台form

<form action="/sysUser/create" method="post">
<input name="roleId" >
<input name="roleId" >
<input name="roleId" >
</form>

后台

public String create(Model model,@Valid SysUserPojo sysUserPojo, BindingResult bindingResult, final RedirectAttributes
            redirectAttributes,@RequestParam(value="roleId", required = false) List<Long> roleIds) {

}

方法二：

前台form

<form action="/sysUser/create" method="post">
<input name="menuIds[0]" >
<input name="menuIds[1]" >
<input name="menuIds[2]" >
</form>

后台

@RequestMapping(value = "/create", method = RequestMethod.POST)
    
    public String create(
            @Valid SysRoleDto sysRoleDto, BindingResult bindingResult, final RedirectAttributes redirectAttributes) {

}

public class SysRoleDto extends SysRolePojo {
    @NotNull
    private List<Long> menuIds;

    public SysRoleDto() {
    }
    public List<Long> getMenuIds() {
        return menuIds;
    }

    public void setMenuIds(List<Long> menuIds) {
        this.menuIds = menuIds;
    }
}

方法三

@ResponseBody
    @RequestMapping(value = "/ajaxsortPriority")
    public ResultDo ajaxsortPriority(@RequestParam("ids[]") Long[] ids) {
        ResultDo resultDo=new ResultDo();
        int size=cmsBannerService.sortPriority(ids);
        if(size==ids.length){
            resultDo.setSuccess(true);
        }else{
            resultDo.setSuccess(false);
        }
        return resultDo;
    }

var param=[];
                    $("#tb_order").find("td[name='id']").each(function(){
                        param.push($(this).text());
                    })
                    var ids={ids:param};
                    $.ajax({
                        cache: true,
                        type: "GET",
                        url: "/cmsBanner/ajaxsortPriority",
                        dataType:"json",
                        data:ids,
                        async: false,
                        success: function (data) {

方法4

@RequestMapping(value = "/cfgRepayRemind", method = RequestMethod.POST)
    @ResponseBody
    public ResultDo<?> cfgRepayRemind(
            @RequestBody List<SysDictPojo> sysDictPojos  //@RequestBody 前台请求的数据格式必须为json

    ) {
        ResultDo<?> resultDo = ResultDo.build();
        try {
            icProjectRepayService.cfgRepayRemind(sysDictPojos);
        } catch (Exception e) {
            resultDo.setSuccess(false);
        }

        return resultDo;
    }

function cfgRepayRemind(ele) {
            var url = $(ele).attr("value");
            var params = [];
            $("#repayRemindMobile").find("ul").each(function () {
                var id = $(this).find("input[name='id']").eq(0).val();
                var value = $(this).find("input[name='value']").eq(0).val();

                params.push({id: id, value: value});//id,value 为java bean里的属性，名字一致
            })

            $.ajax({
                cache: true,
                type: "POST",
                url: url,
                data: JSON.stringify(params),// 指定请求的数据格式为json，实际上传的是json字符串
                contentType: 'application/json;charset=utf-8',//指定请求的数据格式为json,这样后台才能用@RequestBody 接受java bean
                dataType: "json",
                async: false,
                success: function (data) {
                    if (data.success) {
                        toastr.success("操作成功");
                        setTimeout(function () {
                            location.reload();
                        }, 1000)
                    }
                }
            });
        }

public class SysDictPojo extends AbstractBasePojo {
    private Long          id;
    private String        key;
    private String        value;
    private String        description;
   
}

场景一

$.ajax({
            type:"post",
	    data:{total:'100'},
            dataType:'json',
        
            url:"http://127.0.0.1:8089/icProject/test",
            success:function () {

            }
        })

@RequestMapping(value = "/test", method = RequestMethod.POST)
    @ResponseBody
    public String test(@RequestParam("total") String total

    ) {
        return null;
    }

后台可以取到total=100，发现默认是以 application/x-www-form-urlencoded 格式提交请求数据的

场景二

function testpost1() {
        $.ajax({
            type:"post",
            data:{total:'100',icProjectPojo:{totalAmount:10000}},

            dataType:'json',
            url:"http://127.0.0.1:8089/icProject/test",
            success:function () {

            }
        })
    }

icProjectPojo[totalAmount]:

10000 是以这样的key-value 形式提交数据的 ，而不是json对象的方式

@RequestMapping(value = "/test", method = RequestMethod.POST)
    @ResponseBody
    public String test(HttpServletRequest request, @RequestParam("total") String total, IcProjectPojo icProjectPojo

    ) {
        return null;
    }

后台接收时，IcProjectPojo这个bean里的totalAmount明显是就收不到数据的，如果有一个属性叫 icProjectPojo[totalAmount] ,那他会接受到数据

所以传对象要用@RequestBody （方法里只有一个，即必须是一整个对象）和

data:JSON.stringify(params),//此处也不用给对象取key,因为后台的方法里@RequestBody 只允许注解一个对象
contentType: "application/json",

不使用contentType: “application/json”则data可以是对象

使用contentType: “application/json”则data只能是json字符串

方法五：表单数据序列化，ajax提交

var params = $("#sysUserFrm").serialize();
            var url = "/sysUser/settingSave"
            $.ajax({
                cache: true,
                type: "POST",
                url: url,
                data: params,
                dataType: "json",
                async: false,
                success: function (data) {}
            })

@RequestMapping(value = "/settingSave", method = RequestMethod.POST)
    @ResponseBody
    public ResultDo<?> settingSave(SysUserPojo sysUserPojo) {}

这样sysUserPojo也能接收到Bean,其实这里的$("#sysUserFrm").serialize() 就相当于组装的 json对象 { }

ps:

var formData = new Object();
            $("input").each(function () {
                if ($(this).val() == "") {
                    return;
                }
                formData[$(this).attr("name")] = $(this).val();
            });

总结:
get请求
一、url？key1=value1&key2=value2
二、form表单（浏览器network里可看到实际上可是参数加url后面）

java:

@GetMapping("/logined")
    public String logined(@RequestParam(value="userName",required = false) String userName,
                          EpSystemUserPo po,
                          MyUeerPo userPo) {//不采用@RequestBody入参可有多个，可与@RequestParam混用
                            //前台传来userName参数，后台的userName,po中的userName属性，userPo中的userName属性都会接收到值
        return "index";
    }

<form   action="/backend/logined" method="GET" enctype="">
                <div class="form-group">
                    <input  name="userName" placeholder="用户名" >
                </div>
                <div class="form-group">
                    <input type="password" class="form-control" name="password" placeholder="密码" required="">
                </div>
                <button type="submit" >登 录</button>     
 </form>

发起请求后，后台未响应时（比如下了断点）,因为get请求实际就是url后加参数故没有content-type这个参数

后台响应后，响应了会有status code

post请求
一、form表单（同get的区别在于content-type）

后台controller入参同样可以 @RequestParam(value="userName",required = false) String userName,
EpSystemUserPo po, 这样混用

后台未响应时

二、ajax的post方式提交请求

1.不用@RequestBody

后台java

@PostMapping("/logined")
    public String logined(
            @RequestParam(value="userName",required = false) String userName,
                            EpSystemUserPo po,
                          MyUeerPo userPo
    ) {//不采用@RequestBody入参可有多个，可与@RequestParam混用
                            //前台传来userName参数，后台的userName,po中的userName属性，userPo中的userName属性都会接收到值
        return "login";
    }

前台js

function logined() {
                $.ajax({
                    type: "POST",
                    url: "/backend/logined",
                    data: $("#userFrm").serialize(),
                    success: function (data) {}
                })
            }

2.使用@RequestBody(实际上接受的是json的字符串)

@PostMapping("/logined")
    public String logined(
//            @RequestParam(value="userName",required = false) String userName,
                            @RequestBody EpSystemUserPo epSystemUserPo
//                          MyUeerPo userPo
    ) {//采用@RequestBody入参只有一个
        return "login";
    }

function logined() {
                $.ajax({
                    type: "POST",
                    url: "/backend/logined",
                    data:JSON.stringify({userName:"cater",password:"123456"}) ,//转成字符串
                    contentType: "application/json;charset=utf-8",//不使用contentType: “application/json”则data可以是对象,使用contentType: “application/json”则data只能是json字符串
                    success: function (data) {}
                })
            }

这里使用时必须先组装json对象{username:"carter" },我的习惯是用 @RequestBody接受带List对象的对象或者 List对象，因为js中有个push方法组list比较简单，二在页面上通过name="id[0]",这种方式很繁琐，而且动态化[]的索引很难搞

ps:

@PostMapping("createComment")
   @PreAuthorize("hasAnyAuthority('merchant:childComment:index')")
    @ResponseBody
   public ResultDo createComment(
            @RequestParam(value = "childId") Long childId,
            @RequestParam(value = "courseId") Long courseId,
            @RequestParam(value = "classId") Long classId,
            @RequestParam(value = "classScheduleId") Long classScheduleId,
            @RequestParam(value = "content") String content,
            @RequestParam(value = "tagId[]", required = false) List<Long> tagIds
    ) {

var tagIds = []
$.ajax({
                type: "POST",
                url: "/auth/childComment/createComment",
                data: {
                    id: $("#sourceId").val(),
                    courseId: $("#courseId").val(),
                    classId: $("#commentClassId").val(),
                    content: $("#updateContent").val(),
                    childId: $("#childId").val(),
                    classCatalogId: $("#classCatalogId").val(),
                    tagId: tagIds
                },

原文链接：https://blog.csdn.net/feicongcong/article/details/54705933