Spring的Java配置方式简单示例

1. 建立maven工程导入依赖

<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/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.wgm</groupId>
	<artifactId>springjava</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>war</packaging>


	<dependencies>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-webmvc</artifactId>
			<version>4.3.7.RELEASE</version>
		</dependency>
		<!-- 链接池 -->
		<dependency>
			<groupId>com.jolbox</groupId>
			<artifactId>bonecp-spring</artifactId>
			<version>0.8.0.RELEASE</version>
		</dependency>
	</dependencies>
	<build>
		<finalName>${project.artifactId}</finalName>
		<plugins>
			<!-- 资源文件拷贝插件 -->
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-resources-plugin</artifactId>
				<configuration>
					<encoding>UTF-8</encoding>
				</configuration>
			</plugin>
			<!-- java编译插件 -->
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<configuration>
					<source>1.7</source>
					<target>1.7</target>
					<encoding>UTF-8</encoding>
				</configuration>
			</plugin>
		</plugins>
		<pluginManagement>
			<plugins>
				<!-- 配置Tomcat插件 -->
				<plugin>
					<groupId>org.apache.tomcat.maven</groupId>
					<artifactId>tomcat7-maven-plugin</artifactId>
					<version>2.2</version>
				</plugin>
			</plugins>
		</pluginManagement>
	</build>
</project>

2，编写User对象

public class User {

    private String username;

    private String password;

    private Integer age;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

}

3,编写UserDao

public class UserDAO {
    
    public List<User> queryUserList(){
        List<User> result = new ArrayList<User>();
        // 模拟数据库的查询
        for (int i = 0; i < 10; i++) {
            User user = new User();
            user.setUsername("username_" + i);
            user.setPassword("password_" + i);
            user.setAge(i + 1);
            result.add(user);
        }
        return result;
    }

}

4,编写UserService 

@Service
public class UserService {

    @Autowired // 注入Spring容器中的bean对象
    private UserDAO userDAO;

    public List<User> queryUserList() {
        // 调用userDAO中的方法进行查询
        return this.userDAO.queryUserList();
    }

}

5,编写SpringConfig 用于实例化Spring容器

@Configuration // 经过该注解来代表该类是一个Spring的配置，至关于一个xml文件
@ComponentScan(basePackages = "com.wgm") // 配置扫描包
@PropertySource(value = { "classpath:db.properties" })
public class SpringConfig {

	@Bean // 经过该注解来代表是一个Bean对象，至关于xml中的<bean>
	public UserDAO getUserDAO() {
		return new UserDAO(); // 直接new对象作演示
	}

	@Value("${jdbc.url}")
	private String jdbcUrl;

	@Value("${jdbc.driverClassName}")
	private String jdbcDriverClassName;

	@Value("${jdbc.username}")
	private String jdbcUsername;

	@Value("${jdbc.password}")
	private String jdbcPassword;

	@Bean(destroyMethod = "close")
	public DataSource dataSource() {
		BoneCPDataSource boneCPDataSource = new BoneCPDataSource();
		// 数据库驱动
		boneCPDataSource.setDriverClass(jdbcDriverClassName);
		// 相应驱动的jdbcUrl
		boneCPDataSource.setJdbcUrl(jdbcUrl);
		// 数据库的用户名
		boneCPDataSource.setUsername(jdbcUsername);
		// 数据库的密码
		boneCPDataSource.setPassword(jdbcUsername);
		// 检查数据库链接池中空闲链接的间隔时间，单位是分，默认值：240，若是要取消则设置为0
		boneCPDataSource.setIdleConnectionTestPeriodInMinutes(60);
		// 链接池中未使用的连接最大存活时间，单位是分，默认值：60，若是要永远存活设置为0
		boneCPDataSource.setIdleMaxAgeInMinutes(30);
		// 每一个分区最大的链接数
		boneCPDataSource.setMaxConnectionsPerPartition(100);
		// 每一个分区最小的链接数
		boneCPDataSource.setMinConnectionsPerPartition(5);
		return boneCPDataSource;
	}

}

6,编写测试方法

public class Main {
    
    public static void main(String[] args) {
        // 经过Java配置来实例化Spring容器
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(SpringConfig.class);
        
        // 在Spring容器中获取Bean对象
        UserService userService = context.getBean(UserService.class);
        
        // 调用对象中的方法
        List<User> list = userService.queryUserList();
        for (User user : list) {
            System.out.println(user.getUsername() + ", " + user.getPassword() + ", " + user.getPassword());
        }
        
        // 销毁该容器
        context.destroy();
    }

}