Spring的Java配置方式简单示例

1. 创建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>
<!-- 连接池 -->
<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 // 通过该注解来表明该类是一个Spring的配置，相当于一个xml文件
@ComponentScan(basePackages = "com.wgm") // 配置扫描包
@PropertySource(value = { "classpath:db.properties" })
public class SpringConfig {

@Bean // 通过该注解来表明是一个Bean对象，相当于xml中的<bean>
public UserDAO getUserDAO() {
return new UserDAO(); // 直接new对象做演示
}

@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);
// 检查数据库连接池中空闲连接的间隔时间，单位是分，默认值：240，如果要取消则设置为0
boneCPDataSource.setIdleConnectionTestPeriodInMinutes(60);
// 连接池中未使用的链接最大存活时间，单位是分，默认值：60，如果要永远存活设置为0
boneCPDataSource.setIdleMaxAgeInMinutes(30);
// 每个分区最大的连接数
boneCPDataSource.setMaxConnectionsPerPartition(100);
// 每个分区最小的连接数
boneCPDataSource.setMinConnectionsPerPartition(5);
return boneCPDataSource;
}

}

6,编写测试方法

public class Main {

public static void main(String[] args) {
// 通过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();
}

}