spring boot前传(二):读取外部资源文件
通过@PropertySource可以指定读取的配置文件，通过@Value注解获取值，具体用法见案例代码中的注释！这里我们以初始化数据源dataSource为例来演示工程目录阿里巴巴开源的Durid数据源配置文件=========================druidConfig.properties================================d
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通过@PropertySource可以指定读取的配置文件，通过@Value注解获取值，具体用法见案例代码中的注释！
这里我们以初始化数据源dataSource为例来演示
工程目录
阿里巴巴开源的Durid数据源配置文件
=========================druidConfig.properties================================
driverClassName=com.mysql.jdbc.Driver
url=jdbc\:mysql\://localhost\:3306/schooldb
duridUserName=root
password=123456
#配置监控统计拦截的filters，去掉后监控界面sql无法统计
filters=stat
#配置初始化大小
initialSize=6
#配置初始化最大连接数
maxActive=20
#配置最小空闲连接数
minIdle=3
#配置获取连接等待超时的时间,1分钟
maxWait=60000
#检测连接是否有效的SQL
validationQuery=SELECT 'x'
#申请连接的时候检测，如果空闲时间大于timeBetweenEvictionRunsMillis，执行validationQuery检测连接是否有效
testWhileIdle=true
#申请连接时执行validationQuery检测连接是否有效，做了这个配置会降低性能
testOnBorrow=false
#归还连接时执行validationQuery检测连接是否有效，做了这个配置会降低性能
testOnReturn=false
#启用PSCache，必须配置大于0，当大于0时，poolPreparedStatements自动触发修改为true
maxPoolPreparedStatementPerConnectionSize=20
#对于长时间不使用的连接强制关闭
removeAbandoned=true
#超过30秒的空闲连接就可以被关闭了,单位是秒
removeAbandonedTimeout=30
#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
timeBetweenEvictionRunsMillis=10000
#配置一个连接在池中最小生存的时间，单位是毫秒
minEvictableIdleTimeMillis=30000===============================SpringConfig.java=========================
package com.wx.config;
import java.sql.SQLException;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import com.alibaba.druid.pool.DruidDataSource;
import com.wx.dao.IUserDao;
import com.wx.dao.UserDaoImpl;
//通过该注解来表明该类是一个Spring的配置，相当于一个传统的ApplicationContext.xml
@Configuration
// 相当于配置文件里面的<context:component-scan/>标签
@ComponentScan(basePackages = "com.wx.dao,com.wx.biz")
//@PropertySource用来读取外部资源文件
//ignoreResourceNotFound表示忽略没读到的资源文件
@PropertySource(value = { "classpath:druidConfig.properties",
"classpath:jdbc.properties" }, ignoreResourceNotFound = true)
public class SpringConfig {
//Value注解用来获取属性的值
@Value("${driverClassName}")
private String driverClassName;
@Value("${url}")
private String url;
@Value("${duridUserName}")
private String username;
@Value("${password}")
private String password;
@Value("${filters}")
private String filters;
@Value("${initialSize}")
private int initialSize;
@Value("${maxActive}")
private int maxActive;
@Value("${minIdle}")
private int minIdle;
@Value("${maxWait}")
private int maxWait;
@Value("${validationQuery}")
private String validationQuery;
@Value("${testWhileIdle}")
private boolean testWhileIdle;
@Value("${testOnBorrow}")
private boolean testOnBorrow;
@Value("${testOnReturn}")
private boolean testOnReturn;
@Value("${maxPoolPreparedStatementPerConnectionSize}")
private int maxPoolPreparedStatementPerConnectionSize;
@Value("${removeAbandoned}")
private boolean removeAbandoned;
@Value("${removeAbandonedTimeout}")
private int removeAbandonedTimeout;
@Value("${timeBetweenEvictionRunsMillis}")
private int timeBetweenEvictionRunsMillis;
@Value("${minEvictableIdleTimeMillis}")
private int minEvictableIdleTimeMillis;
@Bean(initMethod="init",destroyMethod="close")
public DruidDataSource dataSource(){
DruidDataSource dataSource=new DruidDataSource();
try {
dataSource.setUrl(url);
dataSource.setDriverClassName(driverClassName);
dataSource.setUsername(username);
dataSource.setPassword(password);
dataSource.setFilters(filters);
dataSource.setInitialSize(initialSize);
dataSource.setMaxActive(maxActive);
dataSource.setMinIdle(minIdle);
dataSource.setMaxWait(maxWait);
dataSource.setValidationQuery(validationQuery);
dataSource.setTestWhileIdle(testWhileIdle);
dataSource.setTestOnBorrow(testOnBorrow);
dataSource.setTestOnReturn(testOnReturn);
dataSource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
dataSource.setRemoveAbandoned(removeAbandoned);
dataSource.setRemoveAbandonedTimeout(removeAbandonedTimeout);
dataSource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
dataSource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
System.out.println("数据源初始化成功!");
} catch (SQLException e) {
e.printStackTrace();
}
return dataSource;
}
}
pom配置
==========================pom.xml==================================
<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.wx</groupId>
<artifactId>bootpre02</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>4.3.3.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>4.3.3.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.3.3.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-expression</artifactId>
<version>4.3.3.RELEASE</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<dependency>
<!-- 阿里巴巴druid数据源 -->
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.0.9</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.26</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>
</build>
</project>实体类
==============================UserEntity.java=====================
package com.wx.entitys;
import java.io.Serializable;
public class UserEntity implements Serializable {
private static final long serialVersionUID = 1034088741557780953L;
private Integer userId;
private String userName;
private String passWord;
private String email;
public UserEntity() {
}
public UserEntity(String userName, String passWord) {
super();
this.userName = userName;
this.passWord = passWord;
}
public Integer getUserId() {
return userId;
}
public void setUserId(Integer userId) {
this.userId = userId;
}
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 void setEmail(String email) {
this.email = email;
}
public String getEmail() {
return email;
}
}
=========================================UserDaoImpl.java==========================
package com.wx.dao;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
import javax.sql.DataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import com.wx.entitys.UserEntity;
@Component("userDao")
public class UserDaoImpl implements IUserDao {
@Autowired
private DataSource dataSource;
public List<UserEntity> queryUserList(){
List<UserEntity> userList = new ArrayList<UserEntity>();
Connection conn=null;
try {
conn=dataSource.getConnection();
PreparedStatement psmt=conn.prepareStatement("select * from users");
ResultSet rs=psmt.executeQuery();
UserEntity user=null;
while(rs.next()){
user=new UserEntity();
user.setUserId(rs.getInt("userId"));
user.setUserName(rs.getString("userName"));
user.setPassWord(rs.getString("passWord"));
user.setEmail(rs.getString("email"));
userList.add(user);
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
try {
if(conn!=null){
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
return userList;
}
}
=============================UserBiz.java=========================
package com.wx.biz;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Service;
import com.wx.dao.IUserDao;
import com.wx.entitys.UserEntity;
@Service
public class UserBiz {
//Autowired默认根据类型进行装配，Qualifier根据名称装配
@Autowired
@Qualifier("userDao")
private IUserDao userDao;
public List<UserEntity> queryUserList(){
return userDao.queryUserList();
}
}
测试类
==================TestConfig01.java==============================package com.wx.test;
import java.util.List;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import com.wx.biz.UserBiz;
import com.wx.config.SpringConfig;
import com.wx.entitys.UserEntity;
public class TestConfig01 {
public static void main(String[] args) {
//通过java配置来实例化spring容器
AnnotationConfigApplicationContext ctx=
new AnnotationConfigApplicationContext(SpringConfig.class);
//在spring容器中获取bean对象
//名称userBiz是注解根据类UserBiz自动生成的
UserBiz userBiz=(UserBiz)ctx.getBean("userBiz");
//或者采取下面的方式
//UserBiz userBiz=(UserBiz)ctx.getBean(UserBiz.class);
List<UserEntity> userList=userBiz.queryUserList();
for(UserEntity user:userList){
System.out.print(user.getUserId());
System.out.print("\t"+user.getUserName());
System.out.print("\t"+user.getPassWord());
System.out.println("\t"+user.getEmail());
}
try {
Thread.sleep(100000);
} catch (InterruptedException e) {
e.printStackTrace();
}
//销毁容器
ctx.destroy();
}
}
可以从sqlyog界面观察数据源是否正常启动
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