search
HomeJavajavaTutorialHow Java handles properties resource files

How Java handles properties resource files

Apr 28, 2023 pm 02:19 PM
javaproperties

In the Java language, a text file with a .properties extension is used as a resource file. The content format of this type of file is similar to:

#Comment statement
some_key=some_value

form. Lines starting with # are used as comment lines and will be ignored when processed by the ResourceBundle class; the remaining lines can be described in the form of key name=value.

Java's ResourceBundle class can handle files in this form.

The use of the ResourceBundle class is also very simple. Let's use an example to illustrate.

We assume that we have the following 2 properties files:

TestProperties.properties   view plainprint?  #key=value     userIdLabel=User Id:      userNameLabel=User Name:     #key=value userIdLabel=User Id:   userNameLabel=User Name:   TestProperties_zh_CN.properties   view plainprint?  #key=value     userIdLabel=用户ID:      userNameLabel=用户名:     #key=value userIdLabel=用户ID:   userNameLabel=用户名:

You may notice that there is a _zh_CN name in the TestProperties_zh_CN.properties file name, which is actually used for localization of resource files. . What is localization? Let us briefly explain: When we develop the system, we often need to prepare different interfaces for users in different regions. For example, if a system is targeted at both English-speaking users and Chinese users, we must prepare 2 sets of interfaces for the system. The interface (including messages), one set is English interface and the other is Chinese interface. Of course, apart from the different interfaces, the system processes are exactly the same. Of course, it is impossible for us to develop two different systems for them respectively. What should we do? This requires localization of resources. In other words, different resource files are prepared according to the region or language of the user, so that different interfaces can be prepared for different users but the same set of system logic is used.

The two files above are two different sets of resources.

We use the ResourceBundle class to process the code of different resources:

TestProperties.java   view plainprint?  package com.test.properties;          import java.util.Enumeration;     import java.util.Locale;     import java.util.ResourceBundle;          public class TestProperties  {              public static void main(String []args) {     String resourceFile = "com.test.properties.TestProperties";     //创建一个默认的ResourceBundle对象     //ResourceBundle会查找包com.test.properties下的TestProperties.properties的文件     //com.test.properties是资源的包名,它跟普通java类的命名规则完全一样:     //- 区分大小写     //- 扩展名 .properties 省略。就像对于类可以省略掉 .class扩展名一样     //- 资源文件必须位于指定包的路径之下(位于所指定的classpath中)     //另外,对于非西欧字符(比如中日韩文等),需要使用native2ascii命令或类似工具将其转换成ascii码文件格式,否则会显示乱码。     System.out.println("---Default Locale---");     ResourceBundle resource = ResourceBundle.getBundle(resourceFile);          testResourceBundle(resource);          System.out.println("---Locale.SIMPLIFIED_CHINESE---");          //创建一个指定Locale(本地化)的ResourceBundle对象,这里指定为Locale.SIMPLIFIED_CHINESE     //所以ResourceBundle会查找com.test.properties.TestProperties_zh_CN.properties的文件     //     //中文相关的Locale有:     //Locale.SIMPLIFIED_CHINESE : zh_CN     resource = ResourceBundle.getBundle(resourceFile, Locale.SIMPLIFIED_CHINESE);     //Locale.CHINA  : zh_CN     //Locale.CHINESE: zh     testResourceBundle(resource);          //显示     //         }                  private static void testResourceBundle(ResourceBundle resource) {     //取得指定关键字的value值     String userIdLabel = resource.getString("userIdLabel");     System.out.println(userIdLabel);          //取得所有key值     Enumeration enu = resource.getKeys();          System.out.println("keys:");     while(enu.hasMoreElements()) {         System.out.println(enu.nextElement());     }         }     }     package com.test.properties;   import java.util.Enumeration;  import java.util.Locale;  import java.util.ResourceBundle;   public class TestProperties  {       public static void main(String []args) {  String resourceFile = "com.test.properties.TestProperties";  //创建一个默认的ResourceBundle对象  //ResourceBundle会查找包com.test.properties下的TestProperties.properties的文件  //com.test.properties是资源的包名,它跟普通java类的命名规则完全一样:  //- 区分大小写  //- 扩展名 .properties 省略。就像对于类可以省略掉 .class扩展名一样  //- 资源文件必须位于指定包的路径之下(位于所指定的classpath中)  //另外,对于非西欧字符(比如中日韩文等),需要使用native2ascii命令或类似工具将其转换成ascii码文件格式,否则会显示乱码。  System.out.println("---Default Locale---");  ResourceBundle resource = ResourceBundle.getBundle(resourceFile);   testResourceBundle(resource);   System.out.println("---Locale.SIMPLIFIED_CHINESE---");   //创建一个指定Locale(本地化)的ResourceBundle对象,这里指定为Locale.SIMPLIFIED_CHINESE  //所以ResourceBundle会查找com.test.properties.TestProperties_zh_CN.properties的文件  //  //中文相关的Locale有:  //Locale.SIMPLIFIED_CHINESE : zh_CN  resource = ResourceBundle.getBundle(resourceFile, Locale.SIMPLIFIED_CHINESE);  //Locale.CHINA  : zh_CN  //Locale.CHINESE: zh  testResourceBundle(resource);   //显示  //      }            private static void testResourceBundle(ResourceBundle resource) {  //取得指定关键字的value值  String userIdLabel = resource.getString("userIdLabel");  System.out.println(userIdLabel);   //取得所有key值  Enumeration enu = resource.getKeys();   System.out.println("keys:");  while(enu.hasMoreElements()) {      System.out.println(enu.nextElement());  }      }  }

Explanation:

1, for ease of understanding, we put the explanation in the Java source code, here No more details.

2. For the Chinese resource file TestProperties_zh_CN.properties, you need to use the native2ascii command to convert it to ascii code. For example:

native2ascii -encoding UTF-8 c:\TestProperties_zh_CN.properties c:\java\com\test\properties\TestProperties_zh_CN.properties

As for the detailed usage of native2ascii, I will not go into details here. .

3. Save the above three files in the c:\java\com\test\properties\ directory. Among them, TestProperties_zh_CN.properties is a file converted by native2ascii.

4, compile and execute, it will be displayed on the screen:

c:\java\javac com.test.properties.TestProperties.java

c:\java\ java com.test.properties.TestProperties
---Default Locale---
User Id:
keys:
userNameLabel
userIdLabel
---Locale.SIMPLIFIED_CHINESE---
User ID:
keys:
userNameLabel
userIdLabel

The above is the detailed content of How Java handles properties resource files. For more information, please follow other related articles on the PHP Chinese website!

Statement
This article is reproduced at:亿速云. If there is any infringement, please contact admin@php.cn delete
How does the JVM manage garbage collection across different platforms?How does the JVM manage garbage collection across different platforms?Apr 28, 2025 am 12:23 AM

JVMmanagesgarbagecollectionacrossplatformseffectivelybyusingagenerationalapproachandadaptingtoOSandhardwaredifferences.ItemploysvariouscollectorslikeSerial,Parallel,CMS,andG1,eachsuitedfordifferentscenarios.Performancecanbetunedwithflagslike-XX:NewRa

Why can Java code run on different operating systems without modification?Why can Java code run on different operating systems without modification?Apr 28, 2025 am 12:14 AM

Java code can run on different operating systems without modification, because Java's "write once, run everywhere" philosophy is implemented by Java virtual machine (JVM). As the intermediary between the compiled Java bytecode and the operating system, the JVM translates the bytecode into specific machine instructions to ensure that the program can run independently on any platform with JVM installed.

Describe the process of compiling and executing a Java program, highlighting platform independence.Describe the process of compiling and executing a Java program, highlighting platform independence.Apr 28, 2025 am 12:08 AM

The compilation and execution of Java programs achieve platform independence through bytecode and JVM. 1) Write Java source code and compile it into bytecode. 2) Use JVM to execute bytecode on any platform to ensure the code runs across platforms.

How does the underlying hardware architecture affect Java's performance?How does the underlying hardware architecture affect Java's performance?Apr 28, 2025 am 12:05 AM

Java performance is closely related to hardware architecture, and understanding this relationship can significantly improve programming capabilities. 1) The JVM converts Java bytecode into machine instructions through JIT compilation, which is affected by the CPU architecture. 2) Memory management and garbage collection are affected by RAM and memory bus speed. 3) Cache and branch prediction optimize Java code execution. 4) Multi-threading and parallel processing improve performance on multi-core systems.

Explain why native libraries can break Java's platform independence.Explain why native libraries can break Java's platform independence.Apr 28, 2025 am 12:02 AM

Using native libraries will destroy Java's platform independence, because these libraries need to be compiled separately for each operating system. 1) The native library interacts with Java through JNI, providing functions that cannot be directly implemented by Java. 2) Using native libraries increases project complexity and requires managing library files for different platforms. 3) Although native libraries can improve performance, they should be used with caution and conducted cross-platform testing.

How does the JVM handle differences in operating system APIs?How does the JVM handle differences in operating system APIs?Apr 27, 2025 am 12:18 AM

JVM handles operating system API differences through JavaNativeInterface (JNI) and Java standard library: 1. JNI allows Java code to call local code and directly interact with the operating system API. 2. The Java standard library provides a unified API, which is internally mapped to different operating system APIs to ensure that the code runs across platforms.

How does the modularity introduced in Java 9 impact platform independence?How does the modularity introduced in Java 9 impact platform independence?Apr 27, 2025 am 12:15 AM

modularitydoesnotdirectlyaffectJava'splatformindependence.Java'splatformindependenceismaintainedbytheJVM,butmodularityinfluencesapplicationstructureandmanagement,indirectlyimpactingplatformindependence.1)Deploymentanddistributionbecomemoreefficientwi

What is bytecode, and how does it relate to Java's platform independence?What is bytecode, and how does it relate to Java's platform independence?Apr 27, 2025 am 12:06 AM

BytecodeinJavaistheintermediaterepresentationthatenablesplatformindependence.1)Javacodeiscompiledintobytecodestoredin.classfiles.2)TheJVMinterpretsorcompilesthisbytecodeintomachinecodeatruntime,allowingthesamebytecodetorunonanydevicewithaJVM,thusfulf

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

PhpStorm Mac version

PhpStorm Mac version

The latest (2018.2.1) professional PHP integrated development tool

ZendStudio 13.5.1 Mac

ZendStudio 13.5.1 Mac

Powerful PHP integrated development environment

DVWA

DVWA

Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

Atom editor mac version download

Atom editor mac version download

The most popular open source editor

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor