Maven Spring-Boot：运行REST API时出现问题

Question

I'm using both Spring Boot and Maven for the first time, and have been following This tutorial , with some modifications for what I need to do. I've finished the "Building a REST API" Section, and I want to run the application to make sure what I have so far actually works. When I try the command

mvn spring-boot:run -e >> output.txt

The build fails, and I get the following output , which for me is about five hundred lines of gibberish. Reading through this, I have no idea what's going wrong.

Pet.Java

package com.Me;

import com.fasterxml.jackson.annotation.JsonIgnore;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import java.util.HashSet;
import java.util.Set;

@Entity

public class Pet {

@Id
@GeneratedValue
private Long id;

public Long getId() {
    return id;
}

public String getName() {
    return name;
}

public String getPhoto() {
    return photo;
}

public String getStatus() {
    return status;
}

@JsonIgnore
public String name;
public String photo;
public String status;

public Pet(String name, String photo, String status) {
    this.name = name;
    this.photo = photo;
    this.status = status;
}

Pet() {

}
}

PetRepo.Java

package com.Me;

import org.springframework.data.jpa.repository.JpaRepository;

import java.util.Optional;

public interface PetRepo extends JpaRepository<Pet, Long> {
    Optional<Pet> findByName(String name);
    Optional<Pet> findByStatus (String status);
}

PetstoreApplication.Java

package com.Me;

import java.util.Arrays;
import java.util.Collection;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
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.ResponseStatus;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.support.ServletUriComponentsBuilder;

import org.springframework.boot.autoconfigure.SpringBootApplication;

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class PetstoreApplication {

    @Bean
    CommandLineRunner init(PetRepo petRepo) {
        return (evt) -> Arrays.asList(
                "jhoeller,dsyer,pwebb,ogierke,rwinch,mfisher,mpollack,jlong".split(","))
                .forEach(
                        a -> {
                            Pet pet = petRepo.save(new Pet(a, "meh", "Meh"));
                        });
    }

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

@RestController
@RequestMapping("/{userId}/bookmarks")
class PetRestController {

    private final PetRepo petRepo;

    @RequestMapping(value="/{petId}", method = RequestMethod.GET)
    Pet getPet(@PathVariable Long petId) {
        return this.petRepo.findOne(petId);
    }

    @Autowired
    PetRestController(PetRepo petRepo){
        this.petRepo = petRepo;
    }
}

Pom.xml

<?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>

<groupId>com.Me</groupId>
<artifactId>petstore</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>

<name>petstore</name>
<description>Petstore Project</description>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.3.5.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java.version>1.8</java.version>
</properties>

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

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

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

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

I'm really not sure what's going on and would appreciate a hand with this issue.

Answer 1

I think the clue is at line 112. You haven't provided a database config so spring-boot-starter-data-jpa is trying to find an embedded one automatically and I don't see one being loaded in the listed dependencies. You haven't provided your pom.xml which would be useful but try adding the following dependency to it if you do not have something similar:

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <version>1.2.132</version>
</dependency>

See http://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-sql.html section 29.1.1.

BTW In general when diagnosing issues such as this you want to look for the first exception reported and then for that exception look at the last (nearest the bottom) "Caused by" exception.

HTH