项目总结69： System.getenv()和System.getProperties()

项目总结69： System.getenv()和System.getProperties()

START

import java.util.Map;
import java.util.Properties;
import java.util.Set;

public class SystemEnvironmentTest {

    public static void main(String[] args) {
        //Java提供了System类的静态方法getenv()和getProperty()用于返回系统相关的变量与属性

        // getenv方法返回的变量大多于系统相关
        Map<String, String> envMap = System.getenv();
        Set<String> keySet = envMap.keySet();
        for(String key : keySet){
            System.out.println("key = " + key + "  ||   value = " + envMap.get(key));
        }

        // getProperty方法返回的变量大多与java程序有关。Properties本质是HashTable
        Properties properties = System.getProperties();
        Set<String> nameSet = properties.stringPropertyNames();
        for(String name : nameSet){
            System.out.println("name = " + name + "  ||   value = " + properties.getProperty(name));
        }
    }
}

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日志输出
name = java.runtime.name  ||   value = Java(TM) SE Runtime Environment
name = sun.boot.library.path  ||   value = C:ThsSoftwareJDK8u144x64_thsjdkjrein
name = java.vm.version  ||   value = 25.144-b01
.......

name = java.vm.specification.vendor  ||   value = Oracle Corporation
name = user.variant  ||   value = 
name = os.name  ||   value = Windows 7
name = sun.jnu.encoding  ||   value = GBK

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