白标错误页此应用程序没有显式映射

Question

猜猜我哪里错了。。？

package com.yyy.subject.model;

import javax.persistence.Entity;
import javax.persistence.Id;


@Entity
public class Subject {

    @Id
    private int id;
    private String code;
    private String name;
    private String medium;


    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getCode() {
        return code;
    }
    public void setCode(String code) {
        this.code = code;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getMedium() {
        return medium;
    }
    public void setMedium(String medium) {
        this.medium = medium;
    }   
}

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package com.yyy.subject.repository;

import java.util.List;

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.stereotype.Repository;

import com.yyy.subject.model.Subject;

@Repository
public interface SubjectRepository extends JpaRepository<Subject, Integer> {


@Query("select medium,count(medium) from subject group by medium")
public List<Object[]> findTypeAndTypeCount();   
}
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package com.yyy.subject.service;

import java.util.List;

import org.springframework.stereotype.Service;

import com.yyy.subject.model.Subject;

@Service
public interface SubjectService {

    public Subject create(Subject subject);
    public Subject update(Subject subject);

    public void delete(int id);

    public Subject readOne(int id);

    public List<Subject> readAll();


}
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package com.yyy.subject.service;

import java.util.List;

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

import com.yyy.subject.model.Subject;
import com.yyy.subject.repository.SubjectRepository;

@Service
public class SubjectServiceImpl implements SubjectService {

@Autowired
private SubjectRepository subjectRepository;


    @Override
    public Subject create(Subject subject) {

        return subjectRepository.save(subject);

    }

    @Override
    public Subject update(Subject subject) {
        return subjectRepository.save(subject);
    }

    @Override
    public void delete(int id) {

        subjectRepository.deleteById(id);
    }

    @Override
    public Subject readOne(int id) {
        return subjectRepository.findById(id).get();
    }

    @Override
    public List<Subject> readAll() {



        return (List<Subject>) subjectRepository.findAll();
    }

}
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package com.yyy.subject.util;

import java.util.List;

import org.springframework.stereotype.Component;

@Component
public interface ReportUtil {

    public void generatePieChart(String path,List<Object[]> data);

}
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package com.yyy.subject.util;

import java.io.File;
import java.io.IOException;
import java.util.List;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.data.general.DefaultPieDataset;
import org.springframework.stereotype.Component;

@Component
public class ReportUtilImpl implements ReportUtil {

    @Override
    public void generatePieChart(String path,List<Object[]> data) {


        DefaultPieDataset dataset=new DefaultPieDataset();
        for (Object[] objects : data) {

            dataset.setValue(objects[0].toString(), new Double(objects[1].toString()));
        }

        JFreeChart chart = ChartFactory.createPieChart3D("Report", dataset);
        try {
            ChartUtilities.saveChartAsJPEG(new File(path+"pieChart.jpeg"), chart, 300, 300);
        } catch (IOException e) {
            e.printStackTrace();
        }


    }

}
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package com.yyy.subject.controller;

import java.util.List;

import javax.servlet.ServletContext;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;

import com.yyy.subject.model.Subject;
import com.yyy.subject.repository.SubjectRepository;
import com.yyy.subject.service.SubjectService;
import com.yyy.subject.util.ReportUtil;

@Controller
public class SubjectController {

    @Autowired
    private SubjectService subjectService;

    @Autowired
    private SubjectRepository subjectRepository;

    @Autowired
    private ReportUtil report;

    @Autowired
    private ServletContext sc;


    @RequestMapping("/form33")
    public String create(ModelMap model)
    {
        model.addAttribute("subject", new Subject());
        return "page1";
    }


    @RequestMapping("/form34")
    public String create2(ModelMap model,@ModelAttribute("subject") Subject subject)
    {
        subjectService.create(subject);
        model.addAttribute("msz", "Database created with id:"+subject.getId());
        return "page1"; 
    }

    @RequestMapping("/display")
    public String read(ModelMap model)
    {
        List<Subject> subject = subjectService.readAll();
        model.addAttribute("subject", subject);
        return "page2";

    }

    @RequestMapping("/deleteSubject")
    public String delete(@RequestParam("id") int id,ModelMap model)
    {
        subjectService.delete(id);
        List<Subject> subject = subjectService.readAll();
        model.addAttribute("subject", subject);
        return "page2";
    }
    @RequestMapping("/updateSubject")
    public String edit(@RequestParam("id") int id,ModelMap model)
    {
        Subject subject = subjectService.readOne(id);
        model.addAttribute("subject", subject);
        return "editpage";


    }

    @RequestMapping("/updated")
    public String update(@ModelAttribute("subject") Subject subject1,ModelMap model)
    {
        subjectService.update(subject1);
        List<Subject> subject = subjectService.readAll();

        model.addAttribute("subject", subject);
        return "page2";
    }


    @RequestMapping("/generateReport")
    public String generateReport()
    {
        String path=sc.getRealPath("/");

        List<Object[]> data= subjectRepository.findTypeAndTypeCount();
        report.generatePieChart(path,data);
        return "report";


    }   
}
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package com.yyy.subject;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;


@SpringBootApplication
public class YyySubjectApplication {

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

}
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spring.mvc.view.prefix=/WEB-INF/view/
spring.mvc.view.suffix=.jsp

server.port=9090

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<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.yyy.subject</groupId>
    <artifactId>YYYSubject</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>YYYSubject</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>


<dependency>
    <groupId>org.apache.tomcat.embed</groupId>
    <artifactId>tomcat-embed-jasper</artifactId>
    <scope>provided</scope>
</dependency>




<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jstl</artifactId>
    <scope>provided</scope>
</dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web-services</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
    <groupId>org.hibernate.hql</groupId>
    <artifactId>hibernate-hql-parser</artifactId>
    <version>1.5.0.Final</version>
</dependency>



<dependency>
    <groupId>org.jfree</groupId>
    <artifactId>jfreechart</artifactId>
    <version>1.0.19</version>
</dependency>



        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>


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<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<%@ taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
    <%@ page isELIgnored="false" %>

  <%@ taglib prefix = "c" uri = "http://java.sun.com/jsp/jstl/core" %>  


<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h2><i>Enter Details</i></h2>
<form:form action="form34" modelAttribute="subject" method="post">
Id:<input type="text" name="id"/><br><br>
Code:<form:input path="code"/><br><br>
Name:<form:input path="name"/><br><br>
Medium:<br>
English<form:radiobutton path="medium" value="ENGLISH"/><br>
Hindi<form:radiobutton path="medium" value="HINDI"/><br>
Punjabi<form:radiobutton path="medium" value="PUNJABI"/>
<br><br>
<input type="submit" value="Submit"/>
<br><br>
${msz}
<br><br>
<a href="display">View All</a>
</form:form>
</body>
</html>


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错误：

Error

正在创建名为“subjectController”的bean：通过字段“subjectService”表示未满足的依赖关系；嵌套的异常是org。springframework。豆。工厂未满足的依赖项异常：创建名为“subjectServiceImpl”的bean时出错：通过字段“subjectRepository”表示未满足的依赖项；嵌套的异常是org。springframework。豆。工厂BeanCreationException:创建名为“subjectRepository”的bean时出错：调用init方法失败；嵌套的异常是java。lang.IllegalArgumentException:方法公共抽象java的查询验证失败。util。列表com。yyy。主题存储库。主题库。findTypeAndTypeCount（）！

Caused by: org.hibernate.hql.internal.ast.QuerySyntaxException: subject is not mapped [select medium,count(medium) from subject group by medium]

Answer 1

1） JPQL区分大小写，2）必须使用别名：

@Query("select s.medium, count(s.medium) from Subject s group by s.medium")