本篇，我们介绍下springboot中如何引入properties配置文件，以及如何将properties配置文件中键/值如何注入到spring的bean中。

笔者总结了下，使用较多的大概有两种方式：

一、使用@PropertySource和@Value

     例如，配置jdbc连接池，需要使用到jdbc.properties配置文件 （druid数据库连接池）

DataSourceConfiguration.java

import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;

import com.alibaba.druid.pool.DruidDataSource;

@Configuration
@PropertySource(value = { "classpath:/jdbc.properties"})
public class DataSourceConfig {

	   @Value("${jdbc.driverClassName}")
	   private String driverClassName ;
	   
	   @Value("${jdbc.url}")
	   private String 	url ;
	   
	   @Value("${jdbc.username}")
	   private String username ;
	   
	   @Value("${jdbc.password}")
	   private String password ;
	   
	   @Value("${jdbc.initialSize}")
	   private int  initialSize ;
		 
	  @Value("${jdbc.maxActive}")
	  private int 	maxActive ;
	   
	  @Value("${jdbc.minIdle}")
	  private int 	minIdle ;
	  
	  @Value("${jdbc.maxWait}")
	  private long 	maxWait ;
	  
	   @Value("${jdbc.removeAbandoned}")
	  private boolean 	removeAbandoned ;
	   @Value("${jdbc.removeAbandonedTimeout}")
	  private int 	removeAbandonedTimeout ;
	   
	   @Value("${jdbc.timeBetweenEvictionRunsMillis}")
	  private long timeBetweenEvictionRunsMillis ;
	   @Value("${jdbc.minEvictableIdleTimeMillis}")
	  private long minEvictableIdleTimeMillis ;
	   @Value("${jdbc.validationQuery}")  
	  private String validationQuery ;
	   @Value("${jdbc.testWhileIdle}")
	  private boolean testWhileIdle ;
	   @Value("${jdbc.testOnBorrow}")
	  private boolean testOnBorrow ;
	   @Value("${jdbc.testOnReturn}")
	  private boolean testOnReturn ;
	   @Value("${jdbc.poolPreparedStatements}")
	  private boolean poolPreparedStatements ;
	   
	   @Value("${jdbc.maxPoolPreparedStatementPerConnectionSize}")
	  private int maxPoolPreparedStatementPerConnectionSize ;
	 

		 

	    @Bean(initMethod="init",destroyMethod="close")
	    public DataSource dataSource() {
	    	DruidDataSource  ds=new  DruidDataSource();
	    	ds.setDriverClassName(driverClassName);
	    	ds.setUrl(url);
	    	ds.setUsername(username);
	    	ds.setPassword(password);
	    	ds.setInitialSize(initialSize);
	    	ds.setMaxActive(maxActive);
	    	ds.setMinIdle(minIdle);
	    	ds.setMaxWait(maxWait);
	    	ds.setRemoveAbandoned(removeAbandoned);
	    	ds.setRemoveAbandonedTimeout(removeAbandonedTimeout);
	    	
	    	ds.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
	    	ds.setValidationQuery(validationQuery);
	    	ds.setTestWhileIdle(testWhileIdle);
	    	ds.setTestOnBorrow(testOnBorrow);
	    	ds.setTestOnReturn(testOnReturn);
	    	
	    	ds.setPoolPreparedStatements(poolPreparedStatements);
	    	
	    	ds.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
	    	return ds; 
	    }
	
}

#驱动全类名
jdbc.driverClassName = com.mysql.jdbc.Driver
#jdbc url
jdbc.url =jdbc:mysql://localhost:3306/sbdemo?useUnicode=true&characterEncoding=UTF8&useSSL=false
jdbc.username = root
jdbc.password = 123456
#初始化连接数
jdbc.initialSize = 3
#最大活跃连接数
jdbc.maxActive = 100
#最小空闲连接数
jdbc.minIdle = 2
#最大连接等待时间 毫秒
jdbc.maxWait = 60000
#超过时间限制是否回收
jdbc.removeAbandoned = true
#超时丢弃连接 1800秒    即30分钟
jdbc.removeAbandonedTimeout = 1800
#配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
jdbc.timeBetweenEvictionRunsMillis = 60000
#配置一个连接在池中最小生存的时间，单位是毫秒
jdbc.minEvictableIdleTimeMillis = 300000
#用来检测连接是否有效的sql，要求是一个查询语句	
jdbc.validationQuery = SELECT 1 FROM DUAL
#申请连接的时候检测
jdbc.testWhileIdle =true
#申请连接时执行validationQuery检测连接是否有效，配置为true会降低性能
jdbc.testOnBorrow = false
#归还连接时执行validationQuery检测连接是否有效，配置为true会降低性能 
jdbc.testOnReturn = false
#打开PSCache，并且指定每个连接上PSCache的大小
jdbc.poolPreparedStatements = true
jdbc.maxPoolPreparedStatementPerConnectionSize = 20
# 属性类型是字符串，通过别名的方式配置扩展插件，常用的插件有：  监控统计stat   日志用的log4j 防御SQL注入的wall
#filters =stat,config
# 解密密码必须要配置的项 config, stat启用监控过滤器
# connectionProperties=config.decrypt\=true

二、使用@PropertySource和@ConfigurationProperties

  @ConfigurationProperties 可以一次性注入properties中指定前缀的所有字段(不指定前缀则注入所有字段)，无须用@Value一个个字段的注入，例如项目中配置一个ftp连接。

FTPConfigBean.java

@Component
@PropertySource("classpath:/ftp.properties")
@ConfigurationProperties(prefix="ftp")
public class FTPConfigBean {
	
	private String host ;
	private int port ;
	private String username;
	private String password;
	private int connectTimeOut;
	private String controlEncoding;
	private  int bufferSize;
	private int fileType;
	private  int dataTimeout;
	private boolean useEPSVwithIPv4;
	private  boolean  passiveMode;
	public String getHost() {
		return host;
	}
	public void setHost(String host) {
		this.host = host;
	}
	public int getPort() {
		return port;
	}
	public void setPort(int port) {
		this.port = port;
	}
	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 int getConnectTimeOut() {
		return connectTimeOut;
	}
	public void setConnectTimeOut(int connectTimeOut) {
		this.connectTimeOut = connectTimeOut;
	}
	public String getControlEncoding() {
		return controlEncoding;
	}
	public void setControlEncoding(String controlEncoding) {
		this.controlEncoding = controlEncoding;
	}
	public int getBufferSize() {
		return bufferSize;
	}
	public void setBufferSize(int bufferSize) {
		this.bufferSize = bufferSize;
	}
	public int getFileType() {
		return fileType;
	}
	public void setFileType(int fileType) {
		this.fileType = fileType;
	}
	public int getDataTimeout() {
		return dataTimeout;
	}
	public void setDataTimeout(int dataTimeout) {
		this.dataTimeout = dataTimeout;
	}
	public boolean isUseEPSVwithIPv4() {
		return useEPSVwithIPv4;
	}
	public void setUseEPSVwithIPv4(boolean useEPSVwithIPv4) {
		this.useEPSVwithIPv4 = useEPSVwithIPv4;
	}
	public boolean isPassiveMode() {
		return passiveMode;
	}
	public void setPassiveMode(boolean passiveMode) {
		this.passiveMode = passiveMode;
	}
	@Override
	public String toString() {
		return "FTPConfigBean [host=" + host + ", port=" + port + ", username="
				+ username + ", password=" + password + ", connectTimeOut="
				+ connectTimeOut + ", controlEncoding=" + controlEncoding
				+ ", bufferSize=" + bufferSize + ", fileType=" + fileType
				+ ", dataTimeout=" + dataTimeout + ", useEPSVwithIPv4="
				+ useEPSVwithIPv4 + ", passiveMode=" + passiveMode + "]";
	}
	
	
}

ftp.host=192.168.9.130
ftp.port=21
ftp.username=myftp
ftp.password=123456


#ftp 连接超时时间 毫秒
ftp.connectTimeOut=5000
#控制连接  字符编码
ftp.controlEncoding=UTF-8
#缓冲区大小
ftp.bufferSize=1024
#传输文件类型   2表二进制
ftp.fileType=2
#数据传输超时 毫秒
ftp.dataTimeout=120000
#
ftp.useEPSVwithIPv4=false
#是否启用ftp被动模式
ftp.passiveMode=true