Java 简明教程
Java Properties Class
Introduction
Java Properties 类表示一组持久性属性的类。Properties 既可以保存到流中，也可以从流中加载。以下是有关 Properties 的重要事项 −
The Java Properties class is a class which represents a persistent set of properties. The Properties can be saved to a stream or loaded from a stream. Following are the important points about Properties −
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Each key and its corresponding value in the property list is a string.
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A property list can contain another property list as its 'defaults', this second property list is searched if the property key is not found in the original property list.
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This class is thread-safe; multiple threads can share a single Properties object without the need for external synchronization.
Class declaration
以下是 java.util.Properties 类的声明 −
Following is the declaration for java.util.Properties class −
public class Properties
extends Hashtable<Object,Object>Field
以下是 java.util.Properties 类的字段 −
Following are the fields for java.util.Properties class −
protected Properties defaults − 这是包含此属性列表中找不到的任何键的默认值的属性列表。
protected Properties defaults − This is the property list that contains default values for any keys not found in this property list.
Methods inherited
此类从以下类中继承方法：
This class inherits methods from the following classes −
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java.util.Hashtable
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java.util.Object
Getting an Enumeration of Properties Keys Example
以下示例展示了 java.util.Properties.propertyNames() 方法的用法。
The following example shows the usage of java.util.Properties.propertyNames() method.
package com.tutorialspoint;
import java.util.Enumeration;
import java.util.Properties;
public class PropertiesDemo {
public static void main(String[] args) {
Properties prop = new Properties();
// add some properties
prop.put("Height", "200");
prop.put("Width", "15");
// assign the property names in a enumaration
Enumeration<?> enumeration = prop.propertyNames();
// print the enumaration elements
while(enumeration.hasMoreElements()) {
System.out.println("" + enumeration.nextElement());
}
}
}