Java 字段需要找不到类型为的bean_Java_Spring Boot

Java 字段需要找不到类型为的bean

java spring-boot

Java 字段需要找不到类型为的bean,java,spring-boot,Java,Spring Boot,我是一名SpringBoot学习者，所以我一直在尝试创建一些基本的SpringBoot应用程序。我试图运行开发的应用程序时出错我犯的错误是 [！[ StoreApiAPP.java: package io.ajithan.springbootstarter; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication

我是一名SpringBoot学习者，所以我一直在尝试创建一些基本的SpringBoot应用程序。我试图运行开发的应用程序时出错

我犯的错误是 [！[

StoreApiAPP.java:

package io.ajithan.springbootstarter;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;

@SpringBootApplication
@ComponentScan({"io.ajithan.springbootstarter"})
public class StoreApiAPP {

    public static void main(String[] args) {
        SpringApplication.run(StoreApiAPP.class, args);

    }

}

ItemDetails.java:[软件包名称：io.ajithan.springbootstarter.model]

package io.ajithan.springbootstarter.model;


public class ItemDetails {
    private Integer itemId;
    private String itemName;
    private Double itemPrice;
    private String itemCategory;

    public ItemDetails() {

    }

    public ItemDetails(Integer itemId, String itemName, Double itemPrice, String itemCategory) {
        this.itemId = itemId;
        this.itemName = itemName;
        this.itemPrice = itemPrice;
        this.itemCategory = itemCategory;
    }


    public Integer getItemId() {
        return itemId;
    }
    public void setItemId(Integer itemId) {
        this.itemId = itemId;
    }
    public String getItemName() {
        return itemName;
    }
    public void setItemName(String itemName) {
        this.itemName = itemName;
    }
    public Double getItemPrice() {
        return itemPrice;
    }
    public void setItemPrice(Double itemPrice) {
        this.itemPrice = itemPrice;
    }
    public String getItemCategory() {
        return itemCategory;
    }
    public void setItemCategory(String itemCategory) {
        this.itemCategory = itemCategory;
    }

}

package io.ajithan.springbootstarter.model;

public class ItemResponse {
public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

private String message;
}

package io.ajithan.springbootstarter.controller;


import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import io.ajithan.springbootstarter.model.ItemDetails;
import io.ajithan.springbootstarter.model.ItemResponse;
import io.ajithan.springbootstarter.service.StoreService;

@RestController
public class StoreController {
    @Autowired
    private StoreService storeService; 

    @RequestMapping("/getAllItems")
    public List<ItemDetails> getItemDetailsList(){
        return storeService.getItemDetails();
    }

    @RequestMapping("/getSingleItem/{idNumber}")
    public ItemDetails getSingleItem(@PathVariable("idNumber") Integer id) {
        return storeService.getSingleItem(id);
    }

    @RequestMapping(method=RequestMethod.POST,value="/addItem")
    public ItemResponse addSingleItem(@RequestBody ItemDetails itemDetails) {
        return storeService.addSingleItem(itemDetails);
    }


}

package io.ajithan.springbootstarter.service;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import io.ajithan.springbootstarter.model.ItemDetails;
import io.ajithan.springbootstarter.model.ItemResponse;

@Service
public class StoreService {

    @Autowired
    private ItemResponse itemResponse;

    private List<ItemDetails> itemDetailsList = new ArrayList<>(Arrays.asList(
            new ItemDetails(1,"5Rs GOODDAY Biscuit",5.00,"SWEET"),
            new ItemDetails(2,"10Rs GOODAY Biscuit,",10.00,"SALTY"),
            new ItemDetails(3,"25Rs GOODAY Biscuit",25.00,"CREAMY")
            ));
    public List<ItemDetails> getItemDetails()
    {
        return itemDetailsList;
    }
    public ItemDetails getSingleItem(Integer id) {
        return itemDetailsList.stream().filter(n->n.getItemId().equals(id)).findFirst().get();
    }

    public ItemResponse addSingleItem(ItemDetails itemDetails) {
        itemDetailsList.add(itemDetails);
        itemResponse.setMessage("Item added successfully");
        return itemResponse;
    }

}

ItemResponse.java:[包名：io.ajithan.springbootstarter.model]

package io.ajithan.springbootstarter.model;


public class ItemDetails {
    private Integer itemId;
    private String itemName;
    private Double itemPrice;
    private String itemCategory;

    public ItemDetails() {

    }

    public ItemDetails(Integer itemId, String itemName, Double itemPrice, String itemCategory) {
        this.itemId = itemId;
        this.itemName = itemName;
        this.itemPrice = itemPrice;
        this.itemCategory = itemCategory;
    }


    public Integer getItemId() {
        return itemId;
    }
    public void setItemId(Integer itemId) {
        this.itemId = itemId;
    }
    public String getItemName() {
        return itemName;
    }
    public void setItemName(String itemName) {
        this.itemName = itemName;
    }
    public Double getItemPrice() {
        return itemPrice;
    }
    public void setItemPrice(Double itemPrice) {
        this.itemPrice = itemPrice;
    }
    public String getItemCategory() {
        return itemCategory;
    }
    public void setItemCategory(String itemCategory) {
        this.itemCategory = itemCategory;
    }

}

package io.ajithan.springbootstarter.model;

public class ItemResponse {
public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

private String message;
}

package io.ajithan.springbootstarter.controller;


import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import io.ajithan.springbootstarter.model.ItemDetails;
import io.ajithan.springbootstarter.model.ItemResponse;
import io.ajithan.springbootstarter.service.StoreService;

@RestController
public class StoreController {
    @Autowired
    private StoreService storeService; 

    @RequestMapping("/getAllItems")
    public List<ItemDetails> getItemDetailsList(){
        return storeService.getItemDetails();
    }

    @RequestMapping("/getSingleItem/{idNumber}")
    public ItemDetails getSingleItem(@PathVariable("idNumber") Integer id) {
        return storeService.getSingleItem(id);
    }

    @RequestMapping(method=RequestMethod.POST,value="/addItem")
    public ItemResponse addSingleItem(@RequestBody ItemDetails itemDetails) {
        return storeService.addSingleItem(itemDetails);
    }


}

package io.ajithan.springbootstarter.service;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import io.ajithan.springbootstarter.model.ItemDetails;
import io.ajithan.springbootstarter.model.ItemResponse;

@Service
public class StoreService {

    @Autowired
    private ItemResponse itemResponse;

    private List<ItemDetails> itemDetailsList = new ArrayList<>(Arrays.asList(
            new ItemDetails(1,"5Rs GOODDAY Biscuit",5.00,"SWEET"),
            new ItemDetails(2,"10Rs GOODAY Biscuit,",10.00,"SALTY"),
            new ItemDetails(3,"25Rs GOODAY Biscuit",25.00,"CREAMY")
            ));
    public List<ItemDetails> getItemDetails()
    {
        return itemDetailsList;
    }
    public ItemDetails getSingleItem(Integer id) {
        return itemDetailsList.stream().filter(n->n.getItemId().equals(id)).findFirst().get();
    }

    public ItemResponse addSingleItem(ItemDetails itemDetails) {
        itemDetailsList.add(itemDetails);
        itemResponse.setMessage("Item added successfully");
        return itemResponse;
    }

}

StoreController.java:[包名：io.ajithan.springbootstarter.controller]

package io.ajithan.springbootstarter.model;


public class ItemDetails {
    private Integer itemId;
    private String itemName;
    private Double itemPrice;
    private String itemCategory;

    public ItemDetails() {

    }

    public ItemDetails(Integer itemId, String itemName, Double itemPrice, String itemCategory) {
        this.itemId = itemId;
        this.itemName = itemName;
        this.itemPrice = itemPrice;
        this.itemCategory = itemCategory;
    }


    public Integer getItemId() {
        return itemId;
    }
    public void setItemId(Integer itemId) {
        this.itemId = itemId;
    }
    public String getItemName() {
        return itemName;
    }
    public void setItemName(String itemName) {
        this.itemName = itemName;
    }
    public Double getItemPrice() {
        return itemPrice;
    }
    public void setItemPrice(Double itemPrice) {
        this.itemPrice = itemPrice;
    }
    public String getItemCategory() {
        return itemCategory;
    }
    public void setItemCategory(String itemCategory) {
        this.itemCategory = itemCategory;
    }

}

package io.ajithan.springbootstarter.model;

public class ItemResponse {
public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

private String message;
}

package io.ajithan.springbootstarter.controller;


import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import io.ajithan.springbootstarter.model.ItemDetails;
import io.ajithan.springbootstarter.model.ItemResponse;
import io.ajithan.springbootstarter.service.StoreService;

@RestController
public class StoreController {
    @Autowired
    private StoreService storeService; 

    @RequestMapping("/getAllItems")
    public List<ItemDetails> getItemDetailsList(){
        return storeService.getItemDetails();
    }

    @RequestMapping("/getSingleItem/{idNumber}")
    public ItemDetails getSingleItem(@PathVariable("idNumber") Integer id) {
        return storeService.getSingleItem(id);
    }

    @RequestMapping(method=RequestMethod.POST,value="/addItem")
    public ItemResponse addSingleItem(@RequestBody ItemDetails itemDetails) {
        return storeService.addSingleItem(itemDetails);
    }


}

package io.ajithan.springbootstarter.service;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import io.ajithan.springbootstarter.model.ItemDetails;
import io.ajithan.springbootstarter.model.ItemResponse;

@Service
public class StoreService {

    @Autowired
    private ItemResponse itemResponse;

    private List<ItemDetails> itemDetailsList = new ArrayList<>(Arrays.asList(
            new ItemDetails(1,"5Rs GOODDAY Biscuit",5.00,"SWEET"),
            new ItemDetails(2,"10Rs GOODAY Biscuit,",10.00,"SALTY"),
            new ItemDetails(3,"25Rs GOODAY Biscuit",25.00,"CREAMY")
            ));
    public List<ItemDetails> getItemDetails()
    {
        return itemDetailsList;
    }
    public ItemDetails getSingleItem(Integer id) {
        return itemDetailsList.stream().filter(n->n.getItemId().equals(id)).findFirst().get();
    }

    public ItemResponse addSingleItem(ItemDetails itemDetails) {
        itemDetailsList.add(itemDetails);
        itemResponse.setMessage("Item added successfully");
        return itemResponse;
    }

}

包io.ajithan.springbootstarter.controller；
导入java.util.List；
导入org.springframework.beans.factory.annotation.Autowired；
导入org.springframework.web.bind.annotation.PathVariable；
导入org.springframework.web.bind.annotation.RequestBody；
导入org.springframework.web.bind.annotation.RequestMapping；
导入org.springframework.web.bind.annotation.RequestMethod；
导入org.springframework.web.bind.annotation.RestController；
导入io.ajithan.springbootstarter.model.ItemDetails；
导入io.ajithan.springbootstarter.model.ItemResponse；
导入io.ajithan.springbootstarter.service.StoreService；
@RestController
公共类存储控制器{
@自动连线
私人商店服务；
@请求映射（“/getAllItems”）
公共列表getItemDetailsList（）{
return storeService.getItemDetails（）；
}
@RequestMapping（“/getSingleItem/{idNumber}”）
public ItemDetails getSingleItem（@PathVariable（“idNumber”）整数id）{
return storeService.getSingleItem（id）；
}
@RequestMapping（method=RequestMethod.POST，value=“/addItem”）
public ItemResponse addSingleItem（@RequestBody ItemDetails ItemDetails）{
return storeService.addSingleItem（itemDetails）；
}
}

StoreService.java:[包名：io.ajithan.springbootstarter.service]

package io.ajithan.springbootstarter.model;


public class ItemDetails {
    private Integer itemId;
    private String itemName;
    private Double itemPrice;
    private String itemCategory;

    public ItemDetails() {

    }

    public ItemDetails(Integer itemId, String itemName, Double itemPrice, String itemCategory) {
        this.itemId = itemId;
        this.itemName = itemName;
        this.itemPrice = itemPrice;
        this.itemCategory = itemCategory;
    }


    public Integer getItemId() {
        return itemId;
    }
    public void setItemId(Integer itemId) {
        this.itemId = itemId;
    }
    public String getItemName() {
        return itemName;
    }
    public void setItemName(String itemName) {
        this.itemName = itemName;
    }
    public Double getItemPrice() {
        return itemPrice;
    }
    public void setItemPrice(Double itemPrice) {
        this.itemPrice = itemPrice;
    }
    public String getItemCategory() {
        return itemCategory;
    }
    public void setItemCategory(String itemCategory) {
        this.itemCategory = itemCategory;
    }

}

package io.ajithan.springbootstarter.model;

public class ItemResponse {
public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

private String message;
}

package io.ajithan.springbootstarter.controller;


import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import io.ajithan.springbootstarter.model.ItemDetails;
import io.ajithan.springbootstarter.model.ItemResponse;
import io.ajithan.springbootstarter.service.StoreService;

@RestController
public class StoreController {
    @Autowired
    private StoreService storeService; 

    @RequestMapping("/getAllItems")
    public List<ItemDetails> getItemDetailsList(){
        return storeService.getItemDetails();
    }

    @RequestMapping("/getSingleItem/{idNumber}")
    public ItemDetails getSingleItem(@PathVariable("idNumber") Integer id) {
        return storeService.getSingleItem(id);
    }

    @RequestMapping(method=RequestMethod.POST,value="/addItem")
    public ItemResponse addSingleItem(@RequestBody ItemDetails itemDetails) {
        return storeService.addSingleItem(itemDetails);
    }


}

package io.ajithan.springbootstarter.service;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import io.ajithan.springbootstarter.model.ItemDetails;
import io.ajithan.springbootstarter.model.ItemResponse;

@Service
public class StoreService {

    @Autowired
    private ItemResponse itemResponse;

    private List<ItemDetails> itemDetailsList = new ArrayList<>(Arrays.asList(
            new ItemDetails(1,"5Rs GOODDAY Biscuit",5.00,"SWEET"),
            new ItemDetails(2,"10Rs GOODAY Biscuit,",10.00,"SALTY"),
            new ItemDetails(3,"25Rs GOODAY Biscuit",25.00,"CREAMY")
            ));
    public List<ItemDetails> getItemDetails()
    {
        return itemDetailsList;
    }
    public ItemDetails getSingleItem(Integer id) {
        return itemDetailsList.stream().filter(n->n.getItemId().equals(id)).findFirst().get();
    }

    public ItemResponse addSingleItem(ItemDetails itemDetails) {
        itemDetailsList.add(itemDetails);
        itemResponse.setMessage("Item added successfully");
        return itemResponse;
    }

}

包io.ajithan.springbootstarter.service；
导入java.util.ArrayList；
导入java.util.array；
导入java.util.List；
导入org.springframework.beans.factory.annotation.Autowired；
导入org.springframework.stereotype.Service；
导入io.ajithan.springbootstarter.model.ItemDetails；
导入io.ajithan.springbootstarter.model.ItemResponse；
@服务
公共类存储服务{
@自动连线
私有项响应项响应；
private List itemDetailsList=新建ArrayList（Arrays.asList(
新项目详情（1，“5Rs GOODDAY饼干”，5.00，“甜食”），
新项目详情（2，“10Rs GOODAY饼干”，10.00，“咸”），
新项目详情（3，“25卢比古德饼干”，25.00，“奶油”）
));
公共列表getItemDetails（）
{
返回itemDetailsList；
}
public ItemDetails getSingleItem（整数id）{
返回itemDetailsList.stream（）.filter（n->n.getItemId（）.equals（id））.findFirst（）.get（）；
}
public ItemResponse addSingleItem（ItemDetails ItemDetails）{
itemDetailsList.add（itemDetails）；
setMessage（“项目添加成功”）；
返回项目响应；
}
}

有人能给我这个问题的解决方案吗？

您必须在应用程序中定义ItemResponse bean：

首先在ItemResponse类中添加@Component符号，如下所示：

@Component
public class ItemResponse {
    private String message;

    //** Default Constructor 
    public ItemResponse() {
    }

    //** getter and setter
}

在类配置的某个地方，您必须告诉spring ItemResponse是一个需要注入的bean。如果您有一个带有@configuration符号的类，则声明您的bean，否则创建一个配置类，例如在名为“config”的包中：

别忘了在bean中放一个默认构造函数。祝你好运！

在这种情况下，自动连接

项响应是非常危险的
默认情况下，Spring中的bean是单实例，因此现在有一个ItemResponse
的单个实例。现在想象50个并发线程更改ItemResponse
的单个实例，您认为每个线程将有什么输出
在您的情况下，唯一正确的解决方案是删除autowired字段，并在addSingleItem
方法中构造一个新的ItemResponse
，然后返回它。这样就没有共享状态
@Service
public class StoreService {

    private List<ItemDetails> itemDetailsList = new ArrayList<>(Arrays.asList(
            new ItemDetails(1,"5Rs GOODDAY Biscuit",5.00,"SWEET"),
            new ItemDetails(2,"10Rs GOODAY Biscuit,",10.00,"SALTY"),
            new ItemDetails(3,"25Rs GOODAY Biscuit",25.00,"CREAMY")
            ));

    public List<ItemDetails> getItemDetails()
    {
        return itemDetailsList;
    }
    public ItemDetails getSingleItem(Integer id) {
        return itemDetailsList.stream().filter(n->n.getItemId().equals(id)).findFirst().get();
    }

    public ItemResponse addSingleItem(ItemDetails itemDetails) {
        itemDetailsList.add(itemDetails);
        ItemResponse itemResponse = new ItemResponse();
        itemResponse.setMessage("Item added successfully");
        return itemResponse;
    }
}

@服务
公共类存储服务{
private List itemDetailsList=新建ArrayList（Arrays.asList(
新项目详情（1，“5Rs GOODDAY饼干”，5.00，“甜食”），
新项目详情（2，“10Rs GOODAY饼干”，10.00，“咸”），
新项目详情（3，“25卢比古德饼干”，25.00，“奶油”）
));
公共列表getItemDetails（）
{
返回itemDetailsList；
}
public ItemDetails getSingleItem（整数id）{
返回itemDetailsList.stream（）.filter（n->n.getItemId（）.equals（id））.findFirst（）.get（）；
}
public ItemResponse addSingleItem（ItemDetails ItemDetails）{
itemDetailsList.add（itemDetails）；
ItemResponse ItemResponse=新的ItemResponse（）；
setMessage（“项目添加成功”）；
返回项目响应；
}
}
当然可以。您需要为每个API响应创建一个新的ItemResponse。因此，它不能自动连接，它应该是一个局部变量，而不是一个实例变量。请这样做。（如果您有理由这样做，它可以自动连接，并且它是有意义的。您没有理由这样做，也没有意义，所以不要这样做）是否有可能提供最简单、更精确的代码部分来重现他的问题？同意@kumesana，如果Autowired没有注释为组件/服务…，则不能使用Autowired，并且响应对象不应该是实例变量，除非它是缓存值，每个请求都会得到相同的值e、 那么，你能解释一下我什么时候可以使用@Component注释吗？不要。他应该删除autowired字段，然后在方法内部构造一个新实例。否则，一个实例将在