ADF 11g 界面多語言實現及切換

介紹

現在很多WEB網站都提供了多語言切換功能，在使用ADF創建的WEB應用中，很容易實現多語言，只需簡單的幾個步驟。

2013年6月25日更新：通過在URL後面添加參數改變locale，具體參見代碼。URL如：http://localhost:7101/locale/faces/test.jspx?language=en

效果預覽

實現步驟

一、建立並配置使用資源文件

    1.建立資源文件

       資源文件的文件名結構爲basename_language[_country][_variant].extenstion

           例如UIResource_zh.properties, UIResources_zh_CN.properties

      

    2.在項目中的faces-config.xml中配置資源文件

     

     3.使用資源文件中的項目

          經過上面的配置之後，在頁面上使用資源文件中的項目也變的非常簡單，只需要通過EL編輯器選擇即可。

          

    這樣一來，只需要切換瀏覽器的語言，應用程序會自動根據瀏覽器的語言環境選擇匹配的語言顯示。但是這樣還不能達到實時切換語言的要求，那麼下面的步驟將介紹如何編寫代碼來切換語言。

二、編程切換界面語言

    1.編寫Manage Bean，並且將Manage Bean配置到adfc-config.xml中，選擇合適的scope 

package adf.locale.view;

import java.io.IOException;

import java.util.Locale;

import javax.el.ELContext;
import javax.el.ExpressionFactory;
import javax.el.ValueExpression;

import javax.faces.context.FacesContext;
import javax.faces.event.ValueChangeEvent;

import javax.servlet.http.HttpServletRequest;

import oracle.adf.model.BindingContext;
import oracle.adf.share.ADFContext;
import oracle.adf.view.rich.context.AdfFacesContext;

import oracle.jbo.common.DefLocaleContext;

public class LocaleManager {

    public static final String EL_KEY = "#{localeManager}";

    private String currentLanguage;
    private Locale currentLocale;
    private static LocaleManager instance;

    public LocaleManager() {
        super();
    }

    public static LocaleManager getInstance() {
        if(instance == null) {
            Object value = evaluateEL(EL_KEY);
            if(value instanceof LocaleManager) {
                instance = (LocaleManager)value;
            } else {
                instance = new LocaleManager();
            }
        }
        return instance;
    }

    /**
     * 用於綁定下拉列表的value change，根據用戶選擇的語言，然後刷新頁面。
     * @param event
     * @throws IOException
     */
    public void changeLocale(ValueChangeEvent event) throws IOException {
        String newLanguage = (String)event.getNewValue();
        if (newLanguage != null) {
            this.currentLanguage = newLanguage;
            Locale locale = new Locale(newLanguage);
            this.currentLocale = locale;
            FacesContext ctx = FacesContext.getCurrentInstance();
            HttpServletRequest request =
                (HttpServletRequest)ctx.getExternalContext().getRequest();
            String uri = request.getRequestURI();
            ctx.getExternalContext().redirect(uri);
        }
    }

    private static Object evaluateEL(String el) {
        FacesContext ctx = FacesContext.getCurrentInstance();
        ELContext elCtx = ctx.getELContext();
        ExpressionFactory ef = ctx.getApplication().getExpressionFactory();
        ValueExpression ve = ef.createValueExpression(elCtx, el, Object.class);
        return ve.getValue(elCtx);
    }

    public void setCurrentLanguage(String currentLanguage) {
        this.currentLanguage = currentLanguage;
    }

    public String getCurrentLanguage() {
        return currentLanguage;
    }

    public void setCurrentLocale(Locale currentLocale) {
        this.currentLocale = currentLocale;
    }

    public Locale getCurrentLocale() {
        return currentLocale;
    }
}

    2.編寫並配置ViewHandler類

package adf.locale.view;

import java.io.IOException;

import java.util.Locale;

import javax.el.ELContext;

import javax.el.ExpressionFactory;

import javax.el.ValueExpression;

import javax.faces.FacesException;
import javax.faces.application.ViewHandler;
import javax.faces.component.UIViewRoot;
import javax.faces.context.FacesContext;

public class LocaleSettingViewHandler extends ViewHandler {

    private ViewHandler base;

    public LocaleSettingViewHandler() {
        super();
    }

    public LocaleSettingViewHandler(ViewHandler base) {
        this.base = base;
    }

    public Locale calculateLocale(FacesContext facesContext) {
        LocaleManager localeManager = LocaleManager.getInstance();
        //通過添加URL參數language來改變Locale
        String language =
            facesContext.getExternalContext().getRequestParameterMap().get("language");
        if(language != null) {
            localeManager.setCurrentLanguage(language);
            localeManager.setCurrentLocale(new Locale(language));
        }
        Locale locale = localeManager.getCurrentLocale();
        if(locale == null) {
            locale = Locale.getDefault();
        }
        return locale;
    }

    public String calculateRenderKitId(FacesContext facesContext) {
        return base.calculateRenderKitId(facesContext);
    }

    public UIViewRoot createView(FacesContext facesContext, String string) {
        return base.createView(facesContext, string);
    }

    public String getActionURL(FacesContext facesContext, String string) {
        return base.getActionURL(facesContext, string);
    }

    public String getResourceURL(FacesContext facesContext, String string) {
        return base.getResourceURL(facesContext, string);
    }

    public void renderView(FacesContext facesContext,
                           UIViewRoot uIViewRoot) throws IOException,
                                                         FacesException {
        base.renderView(facesContext, uIViewRoot);
    }

    public UIViewRoot restoreView(FacesContext facesContext, String string) {
        return base.restoreView(facesContext, string);
    }

    public void writeState(FacesContext facesContext) throws IOException {
        base.writeState(facesContext);
    }

    public void setBase(ViewHandler base) {
        this.base = base;
    }

    public ViewHandler getBase() {
        return base;
    }
}

    將LocaleSettingViewHandler配置到faces-config.xml中

    

    3.ADF界面設置

<af:selectOneChoice id="soc1"
                                        label="#{res['login.language.label']}"
                                        value="#{localeManager.currentLanguage}"
                                        valueChangeListener="#{localeManager.changeLocale}"
                                        autoSubmit="true">
                      <af:selectItem label="簡體中文" value="zh" id="si1"/>
                      <af:selectItem label="English" value="en" id="si2"/>
                    </af:selectOneChoice>

特別說明

     還有種方法不用編寫LocaleSettingViewHandler類的，只需要LocaleManager類即可，需要把LocaleManager類中的currentLocale和jspx中view標籤的locale屬性綁定。不過這樣應該需要在每一個jspx頁面中進行設置。可以根據需求靈活選擇不同的方法。

<f:view locale="#{localeManager.currentLocale}">

參考文獻

http://docs.oracle.com/cd/E25178_01/web.1111/b31973/af_global.htm#CHDGCAFI

代碼下載

http://download.csdn.net/detail/ygj26/4891805

轉自：http://blog.csdn.net/ygj26/article/details/8286558