Maven配置本地环境和线上环境

一、问题背景

有时候，我们在开发和部署的时候，有很多配置文件的数据是不一样的，比如数据库的properties文件等等每次部署或者开发都要改配置文件太麻烦了，这个时候，就需要用到maven的profile配置了

Github源码：https://github.com/jxq0816/mvn-profile-demo

二、代码

1、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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.week7i.share</groupId>
  <artifactId>mvn-profile</artifactId>
  <packaging>war</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>mvn-profile Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <properties>
    <commons-lang3.version>3.3.2</commons-lang3.version>
    <commons-io.version>2.4</commons-io.version>
    <guava.version>17.0</guava.version>
    <junit.version>4.11</junit.version>
    <spring.version>4.3.6.RELEASE</spring.version>
  </properties>
  <dependencies>
    <!-- GENERAL UTILS begin -->
    <dependency>
      <groupId>org.apache.commons</groupId>
      <artifactId>commons-lang3</artifactId>
      <version>${commons-lang3.version}</version>
    </dependency>
    <dependency>
      <groupId>commons-io</groupId>
      <artifactId>commons-io</artifactId>
      <version>${commons-io.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <!-- google java lib -->
    <dependency>
      <groupId>com.google.guava</groupId>
      <artifactId>guava</artifactId>
      <version>${guava.version}</version>
    </dependency>

    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>${junit.version}</version>
      <scope>test</scope>
    </dependency>

  </dependencies>

  <build>
    <finalName>mvn-profile</finalName>
    <resources>
      <!--加载环境变量的目录-->
      <resource>
        <directory>src/main/resources/${env}</directory>
      </resource>
      <!--加载其他配置文件-->
      <resource>
        <directory>src/main/resources</directory>
        <excludes>
          <exclude>local/*</exclude>
          <exclude>online/*</exclude>
        </excludes>
      </resource>

    </resources>
  </build>

  <profiles>
    <!--开发环境-->
    <profile>
      <id>local</id>
      <properties>
        <env>local</env>
      </properties>
      <activation>
        <activeByDefault>true</activeByDefault>
      </activation>
    </profile>
    <!--生产环境-->
    <profile>
      <id>online</id>
      <properties>
        <env>online</env>
      </properties>
    </profile>
  </profiles>
</project>

2. 配置 local install

运行local install，会在target看到本地的数据库配置文件加载成功

3. 配置 maven online install

运行online install，会在target看到线上的数据库配置文件加载成功

三、附加功能（读取配置文件）

1、Global.java (全局配置类)

package com.weeking.share.config;

import com.google.common.collect.Maps;
import com.weeking.share.util.PropertiesLoader;
import org.apache.commons.lang3.StringUtils;

import java.util.Map;

/**
 * 全局配置类
 * Created by jiangxingqi on 2017/7/27.
 */
public class Global {

    /**
     * 保存全局属性值
     */
    private static Map<String, String> map = Maps.newHashMap();

    /**
     * 属性文件加载对象
     */
    private static PropertiesLoader loader = new PropertiesLoader("jdbc.properties");

    /**
     * 获取配置
     */
    public static String getConfig(String key) {
        String value = map.get(key);
        if (value == null){
            value = loader.getProperty(key);
            map.put(key, value != null ? value : StringUtils.EMPTY);
        }
        return value;
    }
}

2. PropertiesLoader.java （配置文件读取类）

package com.weeking.share.util;

import org.apache.commons.io.IOUtils;
import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;

import java.io.IOException;
import java.io.InputStream;
import java.util.NoSuchElementException;
import java.util.Properties;


/**
 * Created by jiangxingqi on 2017/7/27.
 */
public class PropertiesLoader {

    private static ResourceLoader resourceLoader = new DefaultResourceLoader();

    private final Properties properties;

    public PropertiesLoader(String... resourcesPaths) {
        properties = loadProperties(resourcesPaths);
    }

    public Properties getProperties() {
        return properties;
    }

    /**
     * 取出Property，但以System的Property优先,取不到返回空字符串.
     */
    private String getValue(String key) {
        String systemProperty = System.getProperty(key);
        if (systemProperty != null) {
            return systemProperty;
        }
        if (properties.containsKey(key)) {
            return properties.getProperty(key);
        }
        return "";
    }

    /**
     * 取出String类型的Property，但以System的Property优先,如果都为Null则抛出异常.
     */
    public String getProperty(String key) {
        String value = getValue(key);
        if (value == null) {
            throw new NoSuchElementException();
        }
        return value;
    }

    /**
     * 取出String类型的Property，但以System的Property优先.如果都为Null则返回Default值.
     */
    public String getProperty(String key, String defaultValue) {
        String value = getValue(key);
        return value != null ? value : defaultValue;
    }

    /**
     * 取出Integer类型的Property，但以System的Property优先.如果都为Null或内容错误则抛出异常.
     */
    public Integer getInteger(String key) {
        String value = getValue(key);
        if (value == null) {
            throw new NoSuchElementException();
        }
        return Integer.valueOf(value);
    }

    /**
     * 取出Integer类型的Property，但以System的Property优先.如果都为Null则返回Default值，如果内容错误则抛出异常
     */
    public Integer getInteger(String key, Integer defaultValue) {
        String value = getValue(key);
        return value != null ? Integer.valueOf(value) : defaultValue;
    }

    /**
     * 取出Double类型的Property，但以System的Property优先.如果都为Null或内容错误则抛出异常.
     */
    public Double getDouble(String key) {
        String value = getValue(key);
        if (value == null) {
            throw new NoSuchElementException();
        }
        return Double.valueOf(value);
    }

    /**
     * 取出Double类型的Property，但以System的Property优先.如果都为Null则返回Default值，如果内容错误则抛出异常
     */
    public Double getDouble(String key, Integer defaultValue) {
        String value = getValue(key);
        return value != null ? Double.valueOf(value) : defaultValue;
    }

    /**
     * 取出Boolean类型的Property，但以System的Property优先.如果都为Null抛出异常,如果内容不是true/false则返回false.
     */
    public Boolean getBoolean(String key) {
        String value = getValue(key);
        if (value == null) {
            throw new NoSuchElementException();
        }
        return Boolean.valueOf(value);
    }

    /**
     * 取出Boolean类型的Property，但以System的Property优先.如果都为Null则返回Default值,如果内容不为true/false则返回false.
     */
    public Boolean getBoolean(String key, boolean defaultValue) {
        String value = getValue(key);
        return value != null ? Boolean.valueOf(value) : defaultValue;
    }

    /**
     * 载入多个文件, 文件路径使用Spring Resource格式.
     */
    private Properties loadProperties(String... resourcesPaths) {
        Properties props = new Properties();

        for (String location : resourcesPaths) {

            InputStream is = null;
            try {
                Resource resource = resourceLoader.getResource(location);
                is = resource.getInputStream();
                props.load(is);
            } catch (IOException ex) {
                System.out.println("Could not load properties from path:" + location + ", " + ex.getMessage());
            } finally {
                IOUtils.closeQuietly(is);
            }
        }
        return props;
    }
}

3. TestProfile.java

import com.weeking.share.config.Global;
import org.junit.Test;

public class TestProfile {
    @Test
    public void profile(){
        String username= Global.getConfig("jdbc.username");
        System.out.println(username);
    }
}

4.测试类运行结果