Java程式教學甘仔店: [JAVA_Spring]建立一個SpringMVC Annotation Project 3 -1 國際化(i18n)

2014年12月18日星期四

[JAVA_Spring]建立一個SpringMVC Annotation Project 3 -1 國際化(i18n)

本文使用 Spring Web model-view-controller (MVC) framework
建立一個簡單的一個Hello World 程式

1、請參考建立一個SpringMVC Annotation Project - Hello World此篇文章，以下是以此作為延伸

2. 文件放置位置

3. 建立Controller & Mapping
在Spring 3 裡大量使用 annotation 。

如：
@Controller
目錄 : src/main/java/com/sample/web/controller
檔名 : HelloController.java

程式碼：

package com.sample.web.controller;

import java.util.Locale;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.MessageSource;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class HelloController{
 
 @Autowired
 MessageSource messageSource;

 @RequestMapping(value = { "/", "/welcome**" }, method = RequestMethod.GET)
 public ModelAndView welcomePage() {
  System.out.println(messageSource.getMessage(
                                                "hello.springmvc", null, Locale.CHINA));
  System.out.println(messageSource.getMessage(
                                                "hello.springmvc", null, Locale.ENGLISH));
  System.out.println(messageSource.getMessage(
                                                "hello.springmvc", null, Locale.TAIWAN));
  return new ModelAndView("hello");
 }

}

5. 建立JSP 頁面
目錄 : src/main/webapp/WEB-INF/pages/
檔名 : hello.jsp

程式碼：
<%@ page contentType="text/html;charset=UTF-8" %>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags" %> <html> <body> Language : <a href="?language=en">English</a>| <a href="?language=zh_CN">Chinese</a>| <a href="?language=zh_TW">Taiwan</a> <h3> hello.springmvc : <spring:message code="hello.springmvc" text="default text" /> </h3> Current Locale : ${pageContext.response.locale} </body> </html>

6. 建立properties 頁面
目錄 : src/main/resources/i18n
檔名 : messages_en.properties

檔名 : messages_zh_CN.properties

檔名 : messages_zh_TW.properties

7. 建立AppConfig.java (Spring設定)
目錄 : src/main/java/com/sample/config
檔名 : AppConfig.java

package com.sample.config;

import java.util.Locale;

import org.springframework.context.MessageSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ReloadableResourceBundleMessageSource;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.LocaleResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.i18n.LocaleChangeInterceptor;
import org.springframework.web.servlet.i18n.SessionLocaleResolver;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;


@EnableWebMvc
@Configuration
@ComponentScan({ "com.sample.web.*" })
public class AppConfig extends WebMvcConfigurerAdapter{
 
    /**
     * 加入SPRING攔截器
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(localeChangeInterceptor());
    }
    
    /**
     * i18n 國際化(可改變區域)
     * @return HandlerInterceptor
     */
    @Bean
    public HandlerInterceptor localeChangeInterceptor() {
        LocaleChangeInterceptor localeChangeInterceptor 
             = new LocaleChangeInterceptor();
        localeChangeInterceptor.setParamName("language");
        return localeChangeInterceptor;
    }
    
    /**
     * 區域解析器
     * @return LocaleResolver
     */
    @Bean
    public LocaleResolver localeResolver() {
     SessionLocaleResolver sessionLocaleResolver = new SessionLocaleResolver();
     sessionLocaleResolver.setDefaultLocale(Locale.TAIWAN);
        return sessionLocaleResolver;
    }
    
    /**
     * i18n文件放置位置
     * @return MessageSource
     */
    @Bean    
    public MessageSource messageSource() {
        ReloadableResourceBundleMessageSource messageSource 
                = new ReloadableResourceBundleMessageSource();
        messageSource.setUseCodeAsDefaultMessage(true);
        messageSource.setBasename("classpath:i18n/messages");
        messageSource.setDefaultEncoding("UTF-8");
        messageSource.setCacheSeconds(0);
        return messageSource;
    }

    /**
     * 頁面導向
     * @return
     */
     @Bean
     public InternalResourceViewResolver viewResolver() {
 InternalResourceViewResolver viewResolver 
     = new InternalResourceViewResolver();
 viewResolver.setViewClass(JstlView.class);
 viewResolver.setPrefix("/WEB-INF/pages/");
 viewResolver.setSuffix(".jsp");
 return viewResolver;
    }
 
}