bean属性注入的4种方式
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2022-07-10 17:55:12
以数据库连接为例,测试bean注入的几种方式JdbcProperties文件:jdbc.driverClassName=com.mysql.jdbc.Driverjdbc.url=jdbc:mysql://127.0.0.1:3306/xxxjdbc.username=rootjdbc.password=xxx@Configuration//声明一个类是一个java配置类, 相当于xml配置文件@EnableConfigurationProperties(JdbcProperties.clas...
以数据库连接为例,测试bean属性注入的几种方式
1.@Autowired注入
2.构造方法注入
3.@Bean方法形参注入
4.直接在@Bean方法上使用@ConfigurationProperties(prefix=“jdbc”)
JdbcProperties文件:
jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/xxx
jdbc.username=root
jdbc.password=xxx
@Configuration//声明一个类是一个java配置类, 相当于xml配置文件
@EnableConfigurationProperties(JdbcProperties.class)
public class JdbcConfiguration {
@Autowired
private JdbcProperties jdbcProperties;
@Value("${jdbc.driverClassName}")
private String driverClassName;
@Value("${jdbc.url}")
private String url;
@Value("${jdbc.username}")
private String username;
@Value("${jdbc.password}")
private String password;
@Bean//把方法的返回值注入到spring 容器
public DataSource dataSource() {
DruidDataSource dataSource = new DruidDataSource();
dataSource.setDriverClassName(this.driverClassName);
dataSource.setUrl(this.url);
dataSource.setUsername(this.username);
dataSource.setPassword(this.password);
return dataSource;
}
application.properties:
jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/leyou
jdbc.username=root
jdbc.password=123
构造方法注入
@Configuration//声明一个类是一个java配置类, 相当于一个xml配置文件
@EnableConfigurationProperties(JdbcProperties.class)
public class JdbcConfiguration {
// @Autowired
private JdbcProperties jdbcProperties;
public JdbcConfiguration(JdbcProperties jdbcProperties) {
this.jdbcProperties = jdbcProperties;
}
@Bean//把方法的返回值注入到spring 容器
public DataSource dataSource() {
DruidDataSource dataSource = new DruidDataSource();
dataSource.setDriverClassName(this.jdbcProperties.getDriverClassName());
dataSource.setUrl(this.jdbcProperties.getUrl());
dataSource.setUsername(this.jdbcProperties.getUsername());
dataSource.setPassword(this.jdbcProperties.getPassword());
return dataSource;
}
}
set方式注入
@ConfigurationProperties(prefix = "jdbc" )
public class JdbcProperties {
private String driverClassName;
private String url;
private String username;
private String password;
public String getDriverClassName() {
return driverClassName;
}
public void setDriverClassName(String driverClassName) {
this.driverClassName = driverClassName;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
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;
}
}
@Configuration//声明一个类是一个java配置类, 相当于一个xml配置文件
@EnableConfigurationProperties(JdbcProperties.class)
public class JdbcConfiguration {
@Autowired
private JdbcProperties jdbcProperties;
@Bean//把方法的返回值注入到spring 容器
public DataSource dataSource() {
DruidDataSource dataSource = new DruidDataSource();
dataSource.setDriverClassName(this.jdbcProperties.getDriverClassName());
dataSource.setUrl(this.jdbcProperties.getUrl());
dataSource.setUsername(this.jdbcProperties.getUsername());
dataSource.setPassword(this.jdbcProperties.getPassword());
return dataSource;
}
}
传参注入
@Configuration//声明一个类是一个java配置类, 相当于一个xml配置文件
@EnableConfigurationProperties(JdbcProperties.class)
public class JdbcConfiguration {
// @Autowired
// private JdbcProperties jdbcProperties;
//
// public JdbcConfiguration(JdbcProperties jdbcProperties) {
// this.jdbcProperties = jdbcProperties;
// }
@Bean//把方法的返回值注入到spring 容器
public DataSource dataSource(JdbcProperties jdbcProperties) {
DruidDataSource dataSource = new DruidDataSource();
dataSource.setDriverClassName( jdbcProperties.getDriverClassName());
dataSource.setUrl( jdbcProperties.getUrl());
dataSource.setUsername( jdbcProperties.getUsername());
dataSource.setPassword( jdbcProperties.getPassword());
return dataSource;
}
}
最简介的方式:要保证返回值有相应的set和get方法,并且配置文件的名称要和返回值属性名称相同
@Configuration//声明一个类是一个java配置类, 相当于一个xml配置文件
@EnableConfigurationProperties(JdbcProperties.class)
public class JdbcConfiguration {
// @Autowired
// private JdbcProperties jdbcProperties;
//
// public JdbcConfiguration(JdbcProperties jdbcProperties) {
// this.jdbcProperties = jdbcProperties;
// }
@Bean//把方法的返回值注入到spring 容器
@ConfigurationProperties(prefix = "jdbc")
public DataSource dataSource(JdbcProperties jdbcProperties) {
DruidDataSource dataSource = new DruidDataSource();
return dataSource;
}
}
本文地址:https://blog.csdn.net/qq_40971668/article/details/110260733
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