问题描述:
Spring+Vue+ElementUI的前后端分离开发项目中,前端向后端发送请求,后端返回错误:Cannot deserialize instance of `java.util.LinkedHashMap` out of START_ARRAY token。
前端代码:
// 获取分页数据
findPage: function (data) {
if(data !== null) {
this.pageRequest = data.pageRequest
}
this.pageRequest.params = [{name:'name', value:this.filters.name}];
this.$api.user.findPage(this.pageRequest).then((res) => {
this.pageResult = res.data
this.findUserRoles()
}).then(data!=null?data.callback:'')
}
后端代码:
分页请求参数Java类:
package com.XXXXX.XXXXX.core.page;//包名
import java.util.HashMap;
import java.util.Map;
/**
* 分页请求*/
public class PageRequest//当前页码
private int pageNum = 1;
//每页数量
private int pageSize = 10;
//其它查询参数
private Map<String, Object> params = new HashMap<>();
public int getPageNum() {
return pageNum;
}
public void setPageNum(int pageNum) {
this.pageNum = pageNum;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
public Map<String, Object> getParams() {
return params;
}
public void setParams(Map<String, Object> params) {
this.params = params;
}
public Object getParam(String key) {
return getParams().get(key);
}
}
后端请求控制器类:
package com.XXXXX.XXXXX.admin.controller;//包名
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.access.prepost.PreAuthorize;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.XXXXX.XXXXX.admin.model.SysLoginLog;//导入的包名
import com.XXXXX.XXXXX.admin.service.SysLoginLogService;
import com.XXXXX.XXXXX.core.http.HttpResult;
import com.XXXXX.XXXXX.core.page.PageRequest;
//登录日志控制器
@RestController
@RequestMapping("loginlog")
public class SysLoginLogController {
@Autowired
private SysLoginLogService sysLoginLogService;
@PreAuthorize("hasAuthority('sys:loginlog:view')")
@PostMapping(value="/findPage")
publicfindPage(@RequestBody PageRequest pageRequest) {
return HttpResult.ok(sysLoginLogService.findPage(pageRequest));
}
@PreAuthorize("hasAuthority('sys:loginlog:delete')")
@PostMapping(value="/delete")
public HttpResult delete(@RequestBody List<SysLoginLog> records) {
return HttpResult.ok(sysLoginLogService.delete(records));
}
}
解决办法:
经过分析发现,后端java类PageRequest的代码中已经声明params为Map<String, Object>类型,但是前端传入的JSON字符串却是数组类型的,后台无法完成转化,因此将前端的数组删除,改为对象类型。否则,辉抛出Cannot deserialize instance of `java.util.LinkedHashMap` out of START_ARRAY token异常。
经过修改后的前端代码如下所示:
// 获取分页数据
findPage: function (data) {
if(data !== null) {
this.pageRequest = data.pageRequest
}
this.pageRequest.params = {name:'name', value:this.filters.name};
this.$api.user.findPage(this.pageRequest).then((res) => {
this.pageResult = res.data
this.findUserRoles()
}).then(data!=null?data.callback:'')
}
参考链接:Can not deserialize instance of java.util.LinkedHashMap out of START_ARRAY token