facing issue while starting spring boot using hikaricp

问题

I have done the same, as some blogs have suggested. But still I couldn't able to solve the issue.

Environment:

spring - 4.2.5.RELEASE
spring boot - 1.3.3.RELEASE
hikariCP - 2.4.7

@Bean(name="HikariDataSource",destroyMethod = "shutdown")
    public DataSource dataSource2() {
        HikariConfig config = new HikariConfig();
        config.setDriverClassName("oracle.jdbc.OracleDriver");
        config.setJdbcUrl("");
        config.setUsername("");
        config.setPassword("");
        config.addDataSourceProperty("cachePrepStmts", "true");
        config.addDataSourceProperty("prepStmtCacheSize", "250");
        config.addDataSourceProperty("prepStmtCacheSqlLimit", "2048");
        config.setPoolName("Hikaripool-1");

        HikariDataSource ds = new HikariDataSource(config);
        return ds;
    }
        @Bean
    public JdbcTemplate getJdbcTemplate() {

        return new JdbcTemplate(dataSource2());
    }

Exception:

java.lang.IllegalStateException: Failed to load ApplicationContext
Caused by: org.springframework.jmx.export.UnableToRegisterMBeanException: Unable to register MBean [HikariDataSource (null)] with key 'dataSource'; nested exception is javax.management.InstanceAlreadyExistsException: com.zaxxer.hikari:name=dataSource,type=HikariDataSource
Caused by: javax.management.InstanceAlreadyExistsException: com.zaxxer.hikari:name=dataSource,type=HikariDataSource

Can anyone help me in resolving this issue.

回答1:

The error "InstanceAlreadyExistsException: com.zaxxer.hikari:name=dataSource" means there is one more instance present for datasource. Please check your configuration. Here is the sample code for jdbcTemplate using HikariCP, Spring Boot 1.4.0 and hsqldb. Please check the HikariCPConnTest.java below. Hope this helps.

pom.xml

<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>Spring-HikariCP</groupId>
<artifactId>com.my</artifactId>
<version>0.0.1-SNAPSHOT</version>
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.4.0.RELEASE</version>
    <relativePath />
</parent>
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <dependency>
        <groupId>org.hsqldb</groupId>
        <artifactId>hsqldb</artifactId>
    </dependency>
    <dependency>
        <groupId>com.zaxxer</groupId>
        <artifactId>HikariCP</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
  </dependencies>
</project>

application.properties

spring.datasource.driverClassName=org.hsqldb.jdbc.JDBCDriver
spring.datasource.url=jdbc:hsqldb:mem:testdb
spring.datasource.username=sa
spring.datasource.password=

HikariCPConn.java

import javax.sql.DataSource;
import org.springframework.context.annotation.Bean;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Component;
import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariDataSource;

@Component
@ConfigurationProperties
public class HikariCPConn {

@Value("${spring.datasource.driverClassName}")
private String driverClassName;

@Value("${spring.datasource.url}")
private String url;

@Value("${spring.datasource.username}")
private String user;

@Value("${spring.datasource.password}")
private String password;

@Bean
public DataSource getDataSource() {
    HikariConfig hikariConfig = new HikariConfig();
    hikariConfig.setUsername(user);
    hikariConfig.setPassword(password);
    hikariConfig.setDriverClassName(driverClassName);
    hikariConfig.setJdbcUrl(url);
    return new HikariDataSource(hikariConfig);
}

@Bean
public JdbcTemplate getJdbcTemplate() {
    return new JdbcTemplate(getDataSource());
   }
}

MySpringBootApp.java

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

@SpringBootApplication
public class MySpringBootApp {
    public static void main(String[] args) {
    SpringApplication.run(new Object[] { MySpringBootApp.class }, args);

   }
}

HikariCPConnTest.java

import java.util.List;
import java.util.Map;
import static org.junit.Assert.assertEquals;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest(classes = MySpringBootApp.class)
public class HikariCPConnTest {

@Autowired
HikariCPConn hkConn;

@Test
public void testInsert() {
    JdbcTemplate jt = hkConn.getJdbcTemplate();
    jt.execute("create table employee (id int, name varchar(20))");
    jt.execute("insert into employee (id, name) values (1, 'Emp1')");
    jt.execute("insert into employee (id, name) values (2, 'Emp2')");
    List<Map<String, Object>> data = jt.queryForList("select * from employee");
    assertEquals(2,data.size());
    for (Map map : data) {
        System.out.println(map);
       }
   }
}

来源：https://stackoverflow.com/questions/39187860/facing-issue-while-starting-spring-boot-using-hikaricp