在大多数项目中我们经常会使用到读取配置文件,用于适配自定义的属性值等,本教程我们主要通过实现对Properties的解析实现基于Guice的配置解析Module.
基础环境
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初始化项目
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mvn archetype:generate -DgroupId=io.edurt.lc.guice -DartifactId=guice-integration-configuration -DarchetypeArtifactId=maven-archetype-quickstart -Dversion=1.0.0 -DinteractiveMode=false
<?xml version="1.0" encoding="UTF-8"?>
<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">
<parent>
<artifactId>lc-guice</artifactId>
<groupId>io.edurt.lc.guice</groupId>
<version>1.0.0</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>guice-integration-configuration</artifactId>
<name>Learning Center for Guice Integration(Configuration)</name>
<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>com.google.inject</groupId>
<artifactId>guice</artifactId>
<version>4.2.3</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
guice: guice就是我们核心要使用的依赖
构建PropertiesUtils
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PropertiesUtils主要用于我们对Properties类型文件的解析.
- 在
src/main/java目录下新建 io.edurt.lc.guice.PropertiesUtils 类文件,在文件输入以下内容
package io.edurt.lc.guice;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
public class PropertiesUtils
{
private PropertiesUtils()
{}
public static Properties loadProperties(String... resourcesPaths)
{
Properties props = new Properties();
for (String location : resourcesPaths) {
File propertiesFile = new File(location);
try (InputStream inputStream = new FileInputStream(propertiesFile)) {
props.load(inputStream);
}
catch (IOException ex) {
ex.printStackTrace();
}
}
return props;
}
public static Integer getIntValue(Properties properties, String key, Integer defaultValue)
{
return Integer.valueOf(getStringValue(properties, key, String.valueOf(defaultValue)));
}
public static String getStringValue(Properties properties, String key, String defaultValue)
{
if (properties == null) {
return defaultValue;
}
if (!properties.containsKey(key)) {
return defaultValue;
}
return String.valueOf(properties.getOrDefault(key, defaultValue));
}
public static Boolean getBoolValue(Properties properties, String key, Boolean defaultValue)
{
return Boolean.valueOf(getStringValue(properties, key, String.valueOf(defaultValue)));
}
}
我们在工具类中提供了几个便捷的方法:
- `getIntValue` 获取Integer类型数据
- `getStringValue` 获取字符串类型数据
- `getBoolValue` 获取Boolean类型数据
- 在
src/main/java目录下新建 io.edurt.lc.guice.ConfigurationModule 类文件,在文件输入以下内容
package io.edurt.lc.guice;
import com.google.inject.AbstractModule;
import com.google.inject.name.Names;
import java.util.Properties;
public class ConfigurationModule
extends AbstractModule
{
private Properties bootstrapConfiguration;
public ConfigurationModule(Properties bootstrapConfiguration)
{
this.bootstrapConfiguration = bootstrapConfiguration;
}
public ConfigurationModule(String configurationFilePath)
{
if (configurationFilePath != null) {
this.bootstrapConfiguration = PropertiesUtils.loadProperties(configurationFilePath);
}
}
@Override
protected void configure()
{
Names.bindProperties(binder(), bootstrapConfiguration);
}
}
测试示例
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- 接下来在
src/test/java目录创建 io.edurt.lc.guice.TestConfigurationModule 类文件进行定义的服务进行测试,添加以下代码
package io.edurt.lc.guice;
import com.google.inject.Guice;
import com.google.inject.Injector;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
public class TestConfigurationModule
{
private String path;
private Injector injector;
@Before
public void before()
{
path = this.getClass().getResource("/file.properties").getPath();
injector = Guice.createInjector(new ConfigurationModule(path));
}
@After
public void after()
{
}
/**
* Method: configure()
*/
@Test
public void testConfigure()
{
Assert.assertTrue(injector.getBindings().toString().contains("Test1"));
}
}
- 在
test/resources目录下新建 file.properties 文件,内容如下:
name=Test1
我们运行程序输出
Connected to the target VM, address: '127.0.0.1:63962', transport: 'socket'
Disconnected from the target VM, address: '127.0.0.1:63962', transport: 'socket'
由于我们使用了断言来操作,所以正常运行后系统不会出现任何输入,如果有错误信息,那么控制台会抛出错误信息.
源码地址
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GitHub
