项目场景：

远程调用时返回json格式错误

项目场景：从分页插件式改换为原生分页的时候 通过openFeign调用时发现了问题

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问题描述

不需要openFeign 调用的时候 返回的数据和格式是对 通过openFeign 调用后返回 出现 application/json 错误 ：

org.springframework.web.client.RestClientException: Error while extracting response for type [cn.cws.framework.core.datasource.util.CwsPage<cn.cws.fulimall.vo.bill.backstage.OrderEntryListVo>] and content type [application/json]

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原因分析：

远程调用后 转换为json格式传输时 错误：

1. JSON 结构与 Java 对象不匹配
2. RestTemplate 配置问题
3. 使用正确的类型引用进行 REST 调用
4. JSON 字段校验
   通过以上的步骤 发现问题出现在这个类 CwsPage 少了一个 setList() 方法

package cn.cws.framework.core.datasource.util;import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.fasterxml.jackson.annotation.JsonIgnore;
import io.swagger.annotations.ApiModel;
import lombok.ToString;import java.util.List;
import java.util.function.Function;import static java.util.stream.Collectors.toList;@ToString
@ApiModel(value = "CwsPage",description = "分页返回数据含分页相关数据")
public class CwsPage<T> extends Page<T> {public CwsPage() {super();}public CwsPage(long current, long size) {super(current, size);}public CwsPage(long current, long size, long total) {super(current, size, total);}public CwsPage(long current, long size, boolean searchCount) {super(current, size, searchCount);}public CwsPage(long current, long size, long total, boolean searchCount) {super(current, size, total, searchCount);}@Deprecated@JsonIgnorepublic long getCurrent() {return this.current;}@Deprecated@JsonIgnorepublic long getSize() {return this.size;}@Deprecated@JsonIgnorepublic List<T> getRecords() {return this.records;}/*** 兼容前端旧数据，现在使用getCurrent* @return*/public Long getPageNum() {return super.getCurrent();}/*** 兼容前端旧数据，现在使用getSize* @return*/public Long getPageSize() {return super.getSize();}/*** 兼容前端旧数据，现在使用getRecords* @return*/public List<T> getList() {return super.getRecords();}public Boolean getLastPage() {return super.getPages() == super.getCurrent();}public Boolean getHasNextPage() {return super.getPages() > super.getCurrent();}public CwsPage<T> setRecords(List<T> records) {this.records = records;return this;}public <R> CwsPage<R> convert(Function<? super T, ? extends R> mapper) {List<R> collect = this.getList().stream().map(mapper).collect(toList());return ((CwsPage<R>) this).setRecords(collect);}}

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解决方案：

通过上面原因分析4步骤 把json 进行解析 发现出问题：

package cn.cws.framework.core.datasource.util;import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.fasterxml.jackson.annotation.JsonIgnore;
import io.swagger.annotations.ApiModel;
import lombok.ToString;import java.util.List;
import java.util.function.Function;import static java.util.stream.Collectors.toList;@ToString
@ApiModel(value = "CwsPage",description = "分页返回数据含分页相关数据")
public class CwsPage<T> extends Page<T> {public CwsPage() {super();}public CwsPage(long current, long size) {super(current, size);}public CwsPage(long current, long size, long total) {super(current, size, total);}public CwsPage(long current, long size, boolean searchCount) {super(current, size, searchCount);}public CwsPage(long current, long size, long total, boolean searchCount) {super(current, size, total, searchCount);}@Deprecated@JsonIgnorepublic long getCurrent() {return this.current;}@Deprecated@JsonIgnorepublic long getSize() {return this.size;}@Deprecated@JsonIgnorepublic List<T> getRecords() {return this.records;}public void setList(List<T> list){this.records = list;}/*** 兼容前端旧数据，现在使用getCurrent* @return*/public Long getPageNum() {return super.getCurrent();}/*** 兼容前端旧数据，现在使用getSize* @return*/public Long getPageSize() {return super.getSize();}/*** 兼容前端旧数据，现在使用getRecords* @return*/public List<T> getList() {return super.getRecords();}public Boolean getLastPage() {return super.getPages() == super.getCurrent();}public Boolean getHasNextPage() {return super.getPages() > super.getCurrent();}public CwsPage<T> setRecords(List<T> records) {this.records = records;return this;}public <R> CwsPage<R> convert(Function<? super T, ? extends R> mapper) {List<R> collect = this.getList().stream().map(mapper).collect(toList());return ((CwsPage<R>) this).setRecords(collect);}}