Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured

问题

I am working on a Spring Boot Batch example with MongoDB and I have already started the mongod server.

When I launch my application, I am getting the error below.

Any pointers for this issue?

***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.

Reason: Failed to determine a suitable driver class


Action:

Consider the following:
    If you want an embedded database (H2, HSQL or Derby), please put it on the classpath.
    If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active).

application.properties:

# Mongo database URI. Cannot be set with host, port and credentials.
spring.data.mongodb.uri=mongodb://localhost/test 

pom.xml

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

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

I have started mongod with the following output:

C:\Users\pc>mongod
2018-07-07T14:39:39.223+0530 I JOURNAL  [initandlisten] journal dir=C:\data\db\journal
2018-07-07T14:39:39.230+0530 I JOURNAL  [initandlisten] recover : no journal files present, no recovery needed
2018-07-07T14:39:39.478+0530 I JOURNAL  [durability] Durability thread started
2018-07-07T14:39:39.589+0530 I CONTROL  [initandlisten] MongoDB starting : pid=11992 port=27017 dbpath=C:\data\db\ 64-bit host=DESKTOP-NQ639DU
2018-07-07T14:39:39.589+0530 I CONTROL  [initandlisten] targetMinOS: Windows 7/Windows Server 2008 R2
2018-07-07T14:39:39.591+0530 I CONTROL  [initandlisten] db version v3.0.5
2018-07-07T14:39:39.592+0530 I CONTROL  [initandlisten] git version: 8bc4ae20708dbb493cb09338d9e7be6698e4a3a3
2018-07-07T14:39:39.592+0530 I CONTROL  [initandlisten] build info: windows sys.getwindowsversion(major=6, minor=1, build=7601, platform=2, service_pack='Service Pack 1') BOOST_LIB_VERSION=1_49
2018-07-07T14:39:39.592+0530 I CONTROL  [initandlisten] allocator: tcmalloc
2018-07-07T14:39:39.593+0530 I CONTROL  [initandlisten] options: {}
2018-07-07T14:39:39.595+0530 I JOURNAL  [journal writer] Journal writer thread started
2018-07-07T14:39:40.485+0530 I NETWORK  [initandlisten] waiting for connections on port 27017
2018-07-07T14:40:39.140+0530 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:51340 #1 (1 connection now open)
2018-07-07T14:40:41.663+0530 I NETWORK  [conn1] end connection 127.0.0.1:51340 (0 connections now open)
2018-07-07T14:45:12.421+0530 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:51578 #2 (1 connection now open)
2018-07-07T14:45:12.870+0530 I NETWORK  [conn2] end connection 127.0.0.1:51578 (0 connections now open)
2018-07-07T14:46:21.734+0530 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:51591 #3 (1 connection now open)
2018-07-07T14:46:22.041+0530 I NETWORK  [conn3] end connection 127.0.0.1:51591 (0 connections now open)
2018-07-07T14:57:47.523+0530 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:52534 #4 (1 connection now open)
2018-07-07T14:57:47.910+0530 I NETWORK  [conn4] end connection 127.0.0.1:52534 (0 connections now open)

回答1:

check your application.properties

changing

spring.datasource.driverClassName=com.mysql.jdbc.Driver

to

spring.datasource.driver-class-name=com.mysql.jdbc.Driver

worked for me. Full config:

spring.datasource.url=jdbc:mysql://localhost:3306/db
spring.datasource.username=
spring.datasource.password=   
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.database-platform = org.hibernate.dialect.MySQL5Dialect
spring.jpa.generate-ddl=true
spring.jpa.hibernate.ddl-auto = update

回答2:

Your problem is the dependency of spring batch spring-boot-starter-batch that has a spring-boot-starter-jdbc transitive maven dependency.

Spring Batch is a framework for building reliable and fault tolerance enterprise batch jobs. It supports many features like restarting a failed batch, recording the status of the batch execution and so on. In order to achieve that Spring Batch uses a database schema to store the status of the registered jobs, the auto-configuration already provides you the basic configuration of the required data source and it is this configuration that requires the relational database configuration.

To solve this you must include some database driver like mysql, h2, etc. to configure the url.

Update: Just for getting start you can configure your application.yml like below:

spring:
  datasource:
    driver-class-name: org.h2.Driver
    url: jdbc:h2:mem:localhost;DB_CLOSE_ON_EXIT=FALSE
    username: admin
    password:

and of course in your pom.xml include the h2 dirver like this:

<?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.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

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

    <dependencies>
       ....
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
        </dependency>

....
    </dependencies>
...

</project>

The motivation, because you can not use mongo for this purpose, is that the usage of mongo is provided only for item readers and writers and not for managing the internal database of Spring Batch that is an internal schema, not a business schema. The query is plain SQL query and the internal abstraction relies on a relational database. It is necessary to have a database with ACID capability because every batch reads and writes a chunk of work and saves that information in order to restart the job. A NoSql solution is not suitable for this.

At the end you have configured a relational database in order to prepare Spring Batch for internal capability, the internal abstraction does not rely on mongo only on jdbc. Then mongo can be used but for the business side of the batch via item reader/writer.

I hope that this can help you to clear your doubts.

回答3:

Not to the point of the question (can be related though), but, if you bootstrap a new project and wondering why do you get the same error, it may come from the artifactId of spring-boot-starter-data-jpa in the dependency section. I gave the dependency below. You will need to define the database to get rid of this.

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

回答4:

“Failed to configure a DataSource” error. First, we fixed the issue by defining the data source. Next, we discussed how to work around the issue without configuring the data source at all.

https://www.baeldung.com/spring-boot-failed-to-configure-data-source

回答5:

Just add : @SpringBootApplication(exclude = {DataSourceAutoConfiguration.class }) works for me.

I was getting same error I tried with @EnableAutoConfiguration(exclude=...) didn't work.

回答6:

For spring boot version 2.X.X below configuration worked for me.

spring.datasource.url=jdbc:mysql://localhost:3306/rest
spring.datasource.username=
spring.datasource.password=
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.jpa.database-platform = org.hibernate.dialect.MySQL5Dialect
spring.jpa.generate-ddl=true
spring.jpa.hibernate.ddl-auto = update 

Old jdbc driver is deprecated. The new one is mentioned on above configuration. Please use the same and restart the project.

回答7:

I had the same issue resolved by add <scope>provided</scope>

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

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

Source: https://github.com/spring-projects/spring-boot/issues/13796#issuecomment-413313346

回答8:

This link helped.

Spring Boot auto-configuration tries to configure beans automatically based on the dependencies added to the classpath. And because we have a JPA dependency (spring-data-starter-jpa) on our classpath, it tries to configure it.

The problem: Spring boot doesn't have the all the info needed to configure the JPA data source i.e. the JDBC connection properties. Solutions:

1. provide the JDBC connection properties (best)
2. postpone supplying connection properties by excluding some AutoConfig classes (temporary - should be removed eventually)

The above link excludes the DataSourceAutoConfiguration.class with

@SpringBootApplication(exclude={DataSourceAutoConfiguration.class})

But this didn't work for me. I instead, had to exclude 2 AutoConfig classes:

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class, XADataSourceAutoConfiguration.class})

回答9:

It simply means you have downloaded a spring starter code with database dependency without configuring your database. So it doesn't know how to connect. For Spring boot version 2.18 do the below steps to fix it.

1. Create a database for the driver you have downloaded ie mysql/mongo etc.

2. In your applications.properties file add the db connection info. Sample is given for mysql if your db is mongo change it for mongo.

   spring.datasource.url=jdbc:mysql://localhost:3306/db_name_that_you_created spring.datasource.username=your_db_username_here spring.datasource.password=your_db_pass_here spring.datasource.driver-class-name=com.mysql.jdbc.Driver spring.jpa.database-platform = org.hibernate.dialect.MySQL5Dialect spring.jpa.generate-ddl=true spring.jpa.hibernate.ddl-auto = update

3. Reboot the server it will be running.

回答10:

It's happening because the @valerio-vaudi said.

Your problem is the dependency of spring batch spring-boot-starter-batch that has a spring-boot-starter-jdbc transitive maven dependency.

But you can resolve it set the primary datasource with your configuration

 @Primary
 @Bean(name = "dataSource")
 @ConfigurationProperties(prefix = "spring.datasource")
 public DataSource getDataSource() {
      return DataSourceBuilder.create().build();
 }

 @Bean
 public JdbcTemplate jdbcTemplate(DataSource dataSource) {
      return new JdbcTemplate(dataSource);
 }

回答11:

If datasource is defined in application.resources, make sure it is locate right under src/main and add it to the build path.

回答12:

Adding h2 dependency to the pom file can resolve such issues. ...... com.h2database h2 ......

回答13:

In my case

spring.profiles = production // remove it to fix

in application.properties was the reason

来源：https://stackoverflow.com/questions/51221777/failed-to-configure-a-datasource-url-attribute-is-not-specified-and-no-embedd