setProperty() method is available in java.util package.
setProperty()方法在java.util包中可用。
setProperty() method is used to set the given value element (val_ele) associated with the given key element (key_ele) when no value element associate previously otherwise it replaces the old value with the given value for the given key of this Properties.
setProperty()方法用于设置与给定键元素(key_ele)关联的给定值元素(val_ele)，前提是之前没有关联的值元素，否则它将用此属性的给定键的给定值替换旧值。
setProperty() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
setProperty()方法是一个非静态方法，只能通过类对象访问，如果尝试使用类名称访问该方法，则会收到错误消息。
setProperty() method does not throw an exception at the time of setting the property.
setProperty()方法在设置属性时不会引发异常。
Syntax:
句法：
public Object setProperty(String key_ele, String val_ele);Parameter(s):
参数：
String key_ele – represents the key element at which the value is to be set.
字符串key_ele –表示要在其上设置值的键元素。
String val_ele – represents the value element for the given key.
字符串val_ele –表示给定键的value元素。
Return value:
返回值：
The return type of the method is Object, it returns the old value linked with the given key if exists otherwise it returns null.
方法的返回类型为Object ，如果存在则返回与给定键链接的旧值，否则返回null。
Example:
例：
// Java program to demonstrate the example // of Object setProperty(String key_ele, String val_ele)// method of Propertiesimport java.io.*;import java.util.*;public class SetPropertyOfProperties { public static void main(String arg[]) throws Exception { // Instantiate Properties object Properties prop = new Properties(); prop.put("10", "C"); prop.put("20", "C++"); prop.put("30", "JAVA"); prop.put("40", "PHP"); prop.put("50", "SFDC"); // By using setProperty() method is to // replace the old value for the given // key if exists with the given new value Object ob = prop.setProperty("20", "包容的菠萝"); // Display old value returned for the // given key element System.out.println("prop.setProperty(20,包容的菠萝): " + ob); // Display updated list prop.list(System.out); }}Output
输出量
prop.setProperty(20,包容的菠萝): C++-- listing properties --50=SFDC40=PHP30=JAVA20=包容的菠萝10=C翻译自: https://www.includehelp.com/java/properties-setproperty-method-with-example.aspx