Java - Comment afficher toutes les propriétés du système
En Java, vous pouvez utiliserSystem.getProperties() pour obtenir toutes les propriétés système.
Properties properties = System.getProperties();
properties.forEach((k, v) -> System.out.println(k + ":" + v)); // Java 8
1. Exemple
DisplayApp.java
package com.example.display;
import java.util.Properties;
public class DisplayApp {
public static void main(String[] args) {
Properties properties = System.getProperties();
// Java 8
properties.forEach((k, v) -> System.out.println(k + ":" + v));
// Classic way to loop a map
//for (Map.Entry entry : properties.entrySet()) {
// System.out.println(entry.getKey() + " : " + entry.getValue());
//}
// No good, output is truncated, long lines end with ...
//properties.list(System.out);
}
}
Sortie
sun.desktop:windows awt.toolkit:sun.awt.windows.WToolkit java.specification.version:10 file.encoding.pkg:sun.io sun.cpu.isalist:amd64 sun.jnu.encoding:Cp1252 java.class.path:D:\maven-examples\maven-profiles\target\classes; java.vm.vendor:"Oracle Corporation" sun.arch.data.model:64 user.variant: java.vendor.url:http://java.oracle.com/ user.timezone: os.name:Windows 10 java.vm.specification.version:10 sun.java.launcher:SUN_STANDARD user.country:MY sun.boot.library.path:C:\opt\Java\jdk-10\bin sun.java.command:com.example.password.DisplayApp jdk.debug:release sun.cpu.endian:little user.home:C:\Users\example user.language:en java.specification.vendor:Oracle Corporation java.version.date:2018-04-17 java.home:C:\opt\Java\jdk-10 file.separator:\ java.vm.compressedOopsMode:Zero based line.separator: java.specification.name:Java Platform API Specification java.vm.specification.vendor:Oracle Corporation java.awt.graphicsenv:sun.awt.Win32GraphicsEnvironment user.script: sun.management.compiler:HotSpot 64-Bit Tiered Compilers java.runtime.version:10.0.1+10 user.name:example path.separator:; os.version:10.0 java.runtime.name:Java(TM) SE Runtime Environment file.encoding:UTF-8 java.vm.name:Java HotSpot(TM) 64-Bit Server VM java.vendor.version:18.3 java.vendor.url.bug:http://bugreport.java.com/bugreport/ java.io.tmpdir:C:\Users\example\AppData\Local\Temp\ java.version:10.0.1 user.dir:D:\maven-examples\maven-profiles os.arch:amd64 java.vm.specification.name:Java Virtual Machine Specification java.awt.printerjob:sun.awt.windows.WPrinterJob sun.os.patch.level: java.library.path:C:\opt\Java\jdk-10\bin;C:\WINDOWS\Sun\Java\bin; java.vendor:Oracle Corporation java.vm.info:mixed mode java.vm.version:10.0.1+10 sun.io.unicode.encoding:UnicodeLittle java.class.version:54.0 Process finished with exit code 0
2. Tri
Exemple pour afficher toutes les propriétés du système par ordre alphabétique.
DisplayApp.java
package com.example.display;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Properties;
import java.util.stream.Collectors;
public class DisplayApp {
public static void main(String[] args) {
Properties properties = System.getProperties();
// Thanks Java 8
LinkedHashMap collect = properties.entrySet().stream()
.collect(Collectors.toMap(k -> (String) k.getKey(), e -> (String) e.getValue()))
.entrySet().stream().sorted(Map.Entry.comparingByKey())
.collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue,
(oldValue, newValue) -> oldValue, LinkedHashMap::new));
collect.forEach((k, v) -> System.out.println(k + ":" + v));
}
}
Sortie
awt.toolkit:sun.awt.windows.WToolkit file.encoding:UTF-8 file.encoding.pkg:sun.io file.separator:\ java.awt.graphicsenv:sun.awt.Win32GraphicsEnvironment java.awt.printerjob:sun.awt.windows.WPrinterJob //... sun.cpu.endian:little sun.cpu.isalist:amd64 sun.desktop:windows sun.io.unicode.encoding:UnicodeLittle sun.java.command:com.example.password.DisplayApp sun.java.launcher:SUN_STANDARD sun.jnu.encoding:Cp1252 sun.management.compiler:HotSpot 64-Bit Tiered Compilers sun.os.patch.level: user.country:MY user.dir:D:\maven-examples\maven-profiles user.home:C:\Users\example user.language:en user.name:example user.script: user.timezone: user.variant: