Java中有個比較重要的類Properties(Java.util.Properties),主要用于讀取Java的配置文件,各種語言都有自己所支 持的配置文件,配置文件中很多變量是經常改變的,這樣做也是為了方便用戶,讓用戶能夠脫離程序本身去修改相關的變量設置。今天,我們就開始Properties的使用。
Java中Properties的使用
Properties的文檔說明:
The Properties class represents a persistent set of properties. The Properties can be saved to a stream or loaded from a stream. Each key and its corresponding value in the property list is a string.
Properties類的描述:
public class Properties extends Hashtable<Object,Object>
測試的項目結構如下:
一、在huhx.properties文件中,我們為也方便,加入一條數據:
name=huhx
二、將huhx.properties文件加載讀取,得到相應的屬性
1
2
3
4
|
Properties properties = new Properties(); FileInputStream fis = new FileInputStream( "huhx.properties" ); properties.load(fis); System.out.println(properties.get( "name" )); |
三、Properties的list方法的使用
1
2
|
PrintStream printStream = System.out; properties.list(printStream); |
list方法的具體代碼:
1
2
3
4
5
6
7
8
9
10
11
12
13
|
public void list(PrintStream out) { out.println( "-- listing properties --" ); Hashtable h = new Hashtable(); enumerate(h); for (Enumeration e = h.keys() ; e.hasMoreElements() ;) { String key = (String)e.nextElement(); String val = (String)h.get(key); if (val.length() > 40 ) { val = val.substring( 0 , 37 ) + "..." ; } out.println(key + "=" + val); } } |
四、Properties的store方法的使用
1
2
|
OutputStream outputStream = new FileOutputStream( "huhx.txt" ); properties.store(outputStream, "comments" ); |
五、Properties的storeToXML方法的使用
1
2
|
OutputStream outputStream2 = new FileOutputStream( "huhx.xml" ); properties.storeToXML(outputStream2, "comments" ); |
六、最終生成的文件如下:
huhx.txt:
1
2
3
|
#comments #Thu May 19 19 : 19 : 36 CST 2016 name=huhx |
huhx.xml:
1
2
3
4
5
6
|
<?xml version= "1.0" encoding= "UTF-8" standalone= "no" ?> <properties> <comment>comments</comment> <entry key= "name" >huhx</entry> </properties> |
友情鏈接,PropertiesTest.java:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
|
package com.huhx.linux; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.OutputStream; import java.io.PrintStream; import java.util.Properties; public class PropertiesTest { public static void main(String[] args) throws Exception { // 一般Properties的使用 Properties properties = new Properties(); FileInputStream fis = new FileInputStream( "huhx.properties" ); properties.load(fis); System.out.println(properties.get( "name" )); // 以下是測試的部分 PrintStream printStream = System.out; properties.list(printStream); OutputStream outputStream = new FileOutputStream( "huhx.txt" ); properties.store(outputStream, "comments" ); OutputStream outputStream2 = new FileOutputStream( "huhx.xml" ); properties.storeToXML(outputStream2, "comments" ); } } |
以上所述是小編給大家介紹的Java中Properties的使用詳解,希望對大家有所幫助,如果大家有任何疑問請給我留言,小編會及時回復大家的。在此也非常感謝大家對服務器之家網站的支持!