使用Spring Boot快速构建基于SQLite数据源的应用

为了提供一个单包易部署的服务器应用，考虑使用spring boot，因为其集成了apache tomcat，易于运行，免去绝大部分了服务器配置的步骤。

项目初始化

首先从mvn archetype:generate中选择 com.github.mkspcd:simple-webapp(或其他webapp模版) 模版生成项目结构。

更多关于maven请移步maven - users centre

在pom.xml中添加parent来获取spring boot所需的最小依赖。

<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/maven-v4_0_0.xsd">
  <modelversion>4.0.0</modelversion>
  <groupid>com.github.hwding.example</groupid>
  <artifactid>example</artifactid>
  <packaging>jar</packaging>
  <version>0.0.1</version>
  <name>an example</name>
  <url>https://github.com/hwding</url>
  <!-- 添加spring的repository以便于添加相关组件 -->
  <repositories>
    <repository>
      <url>http://repo.spring.io/milestone/</url>
      <id>repo-spring</id>
    </repository>
  </repositories>
  <parent>
    <groupid>org.springframework.boot</groupid>
    <artifactid>spring-boot-starter-parent</artifactid>
    <version>1.5.6.release</version>
  </parent>
  <build>
    <finalname>example</finalname>
    <plugins>
      <plugin>
        <groupid>org.springframework.boot</groupid>
        <artifactid>spring-boot-maven-plugin</artifactid>
      </plugin>
      <!-- 编译级别，可选 -->
      <plugin>
        <groupid>org.apache.maven.plugins</groupid>
        <artifactid>maven-compiler-plugin</artifactid>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
      </plugin>
    </plugins>
  </build>
  <dependencies>
    <dependency>
      <groupid>org.springframework.boot</groupid>
      <artifactid>spring-boot-starter-web</artifactid>
    </dependency>
    <dependency>
      <groupid>org.springframework.boot</groupid>
      <artifactid>spring-boot-starter-data-jpa</artifactid>
    </dependency>
    <!-- 用于hibernate4的sqlite3 dialect -->
    <dependency>
      <groupid>com.enigmabridge</groupid>
      <artifactid>hibernate4-sqlite-dialect</artifactid>
      <version>0.1.2</version>
    </dependency>
    <!-- 用于配置数据源 -->
    <dependency>
      <groupid>org.apache.commons</groupid>
      <artifactid>commons-dbcp2</artifactid>
      <version>2.1.1</version>
    </dependency>
    <dependency>
      <groupid>org.eclipse.persistence</groupid>
      <artifactid>javax.persistence</artifactid>
      <version>2.2.0-rc1</version>
    </dependency>
    <!-- sqlite3 驱动 -->
    <dependency>
      <groupid>org.xerial</groupid>
      <artifactid>sqlite-jdbc</artifactid>
      <version>3.20.0</version>
    </dependency>
  </dependencies>
</project>

pom中同时添加了hibernate以及spring jpa等相关组件。

配置数据源

@configuration
public class datasourceconfiguration {
  @bean(destroymethod = "", name = "embeddeddatasource")
  public datasource datasource() {
    datasourcebuilder datasourcebuilder = datasourcebuilder.create();
    datasourcebuilder.driverclassname("org.sqlite.jdbc");
    datasourcebuilder.url("jdbc:sqlite:" + "example.db");
    datasourcebuilder.type(sqlitedatasource.class);
    return datasourcebuilder.build();
  }
}

这里设置了该bean的destroymethod = ""是为了防止停止服务器时容器管理器两次销毁导致的异常，name = "embeddeddatasource"用于在自动装配bean时与其他datasource加以区分。

为了使该独立服务易部署易分发，使用sqlite3作为数据存取的源，值得注意的是，该场景非常少见。

配置spring data jpa

@configuration
@enablejparepositories(
    basepackages = "com.github.hwding.example.data.repository",
    transactionmanagerref = "jpatransactionmanager",
    entitymanagerfactoryref = "localcontainerentitymanagerfactorybean"
)
@enabletransactionmanagement
public class jpaconfiguration {
  @autowired
  @bean
  public jpatransactionmanager jpatransactionmanager(@qualifier(value = "embeddeddatasource") datasource datasource, entitymanagerfactory entitymanagerfactory) {
    jpatransactionmanager jpatransactionmanager
        = new jpatransactionmanager();
    jpatransactionmanager.setentitymanagerfactory(entitymanagerfactory);
    jpatransactionmanager.setdatasource(datasource);
    return jpatransactionmanager;
  }
  @autowired
  @bean
  localcontainerentitymanagerfactorybean localcontainerentitymanagerfactorybean(@qualifier(value = "embeddeddatasource") datasource datasource, jpavendoradapter jpavendoradapter) {
    localcontainerentitymanagerfactorybean localcontainerentitymanagerfactorybean
        = new localcontainerentitymanagerfactorybean();
    localcontainerentitymanagerfactorybean.setdatasource(datasource);
    localcontainerentitymanagerfactorybean.setpackagestoscan("com.github.hwding.example.data.model.local");
    localcontainerentitymanagerfactorybean.setjpavendoradapter(jpavendoradapter);
    return localcontainerentitymanagerfactorybean;
  }
  @bean
  public jpavendoradapter jpavendoradapter() {
    hibernatejpavendoradapter hibernatejpavendoradapter = new hibernatejpavendoradapter();
    hibernatejpavendoradapter.setgenerateddl(true);
    hibernatejpavendoradapter.setshowsql(true);
    hibernatejpavendoradapter.setdatabaseplatform("com.enigmabridge.hibernate.dialect.sqlitedialect");
    return hibernatejpavendoradapter;
  }
}

注意repository和entity扫描的包路径需要根据实际进行调整。

hibernatejpavendoradapter.setgenerateddl(true);能够在初次运行时自动根据entity的定义生成ddl并自动创建sqlite3的 .db 数据文件，在本例中是 example.db ，ddl会最小程度的满足entity的定义；如果该文件已经存在，则并不会对其进行覆盖。

由于hibernate并不对sqlite3提供支持，所以需要提供第三方dialect给它：hibernatejpavendoradapter.setdatabaseplatform("com.enigmabridge.hibernate.dialect.sqlitedialect");，这个类我们已经在pom中引入了。

配置入口

@springbootapplication
public class application {
  public static void main(string[] args) {
    springapplication.run(application.class);
  }
}

spring boot能够从jar包的入口直接启动整个应用程序。

总结

以上所述是小编给大家介绍的使用spring boot快速构建基于sqlite数据源的应用，希望对大家有所帮助