Servlet中实现通过Rhino在Java中调用JavaScript

﹏ヽ暗。殇╰゛Y 2022-06-16 14:11 213阅读 0赞

本篇博客解决上篇博客 [采用Rhino在JAVA中运行JavaScript][Rhino_JAVA_JavaScript] 中提到的问题，即在执行cx.evaluateReader(scope, in, f, 1, null)时报出的数组越界的异常问题。  
由于Rhino是开源的，所以将工程中的rhino-1.7.7.1.jar文件由源码替换后，加断点调试发现，当代码执行到如下图所示代码时，在获取org包时报错

![Center][]

在往深处调试，正在报错的语句为如下图：

![Center 1][]

servlet中在加载org包时，报StringIndexOutOfBoundsException：String index out of range:3错误，**解决方法是**如上图最后一个catch语句捕获StringIndexOutOfBoundsException该错误即可，便能解决这个问题

下面将导出word的servlet类贴与此处：

package com.rhino.servlet;
    
    import java.io.FileNotFoundException;
    import java.io.FileReader;
    import java.io.IOException;
    import java.lang.reflect.InvocationTargetException;
    import java.net.URLEncoder;
    
    import javax.servlet.ServletException;
    import javax.servlet.ServletOutputStream;
    import javax.servlet.annotation.WebServlet;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import org.mozilla.javascript.Context;
    import org.mozilla.javascript.ContextFactory;
    import org.mozilla.javascript.Function;
    import org.mozilla.javascript.Scriptable;
    import org.mozilla.javascript.ScriptableObject;
    
    import com.rhino.test.ExtendUtil;
    
    import net.sf.json.JSONArray;
    
    /**
     * Servlet implementation class ExportWordServlet
     */
    @WebServlet("/ExportWordServlet")
    public class ExportWordServlet extends HttpServlet {
    	private static final long serialVersionUID = 1L;
    
        /**
         * Default constructor. 
         */
        public ExportWordServlet() {
            // TODO Auto-generated constructor stub
        }
    
    	/**
    	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
    	 */
    	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		Context cx = ContextFactory.getGlobal().enterContext();
    		Scriptable scope = cx.initStandardObjects(null);
    		cx.setOptimizationLevel(-1);
    		cx.setLanguageVersion(Context.VERSION_1_8);
    
    		String[] file = {  "/lib/env.rhino.1.2.js", "/lib/jquery.js" ,"/lib/batchExportWord.js"};
    		
    		String exportContext = "";
    		try {
    			ScriptableObject.defineClass(scope, ExtendUtil.class);
    		} catch (IllegalAccessException e1) {
    			e1.printStackTrace();
    		} catch (InstantiationException e1) {
    			e1.printStackTrace();
    		} catch (InvocationTargetException e1) {
    			e1.printStackTrace();
    		}
    		ExtendUtil util = (ExtendUtil) cx.newObject(scope, "util");
    		scope.put("util", scope, util);
    		for (String f : file) {
    			try {
    				FileReader in = null;
    				in = new FileReader(ExportWordServlet.class.getResource("/").toString().substring(6)+"/com/rhino/test/"+f);
    				cx.evaluateReader(scope, in, f, 1, null);
    				if(f.equalsIgnoreCase("/lib/batchExportWord.js")){
    					String jsFunction = "exportWord";
    					Object fObj = scope.get(jsFunction, scope);
    		            if (!(fObj instanceof Function)) {
    		                System.out.println("找不到方法" +jsFunction);
    		            } else {
    		            	String jsonStr ="{name:'张三',sex:'男',birthday:'1981.10',faceImg:'./img/face.jpg'fullTimeSchooling:{academicQualification:'大学本科',degree:'工学学士',university:'成都信息工程学院银杏酒店管理学院',major:'科学社会主义与国际共产主义运动'}";
    		            	Object functionArgs[] = {jsonStr};
    		                Function fo = (Function)fObj;
    		                Object result = fo.call(cx, scope, scope, functionArgs);
    		                exportContext = Context.toString(result);
    		                String filename=URLEncoder.encode("干部任免审批表","utf-8"); //解决中文文件名下载后乱码的问题  
    
    		                response.setCharacterEncoding("utf-8");  
    		                response.setHeader("Content-Disposition","attachment; filename="+filename+".doc");  
    		                //获取响应报文输出流对象  
    		                ServletOutputStream  out =response.getOutputStream();  
    		                //输出  
    		               
    		                out.write(exportContext.getBytes());
    		                out.flush();  
    		                out.close(); 
    		            }
    				}
    			} catch (FileNotFoundException e1) {
    				e1.printStackTrace();
    			} catch (IOException e1) {
    				e1.printStackTrace();
    			}
    		}
    		
    	}
    
    	/**
    	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
    	 */
    	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    		// TODO Auto-generated method stub
    		doGet(request, response);
    	}
    
    }

在batchExportWord.js的exportWord函数中，需要将所传如的字符串转变成json格式的，js中string转json使用eval函数即可，即jsonData = eval('('+jsonStr+'));即可

在Rhino中要能使用jQuery需要引入env.rhino.1.2.js，[可以从此下载][Link 1]。

[Rhino_JAVA_JavaScript]: http://blog.csdn.net/fengshuiyue/article/details/72134932
[Center]: /images/20220616/1087fcfd116747eda96197e784703fa6.png
[Center 1]: /images/20220616/60feeb4c8e4a4798bc49d89392cdfccb.png
[Link 1]: http://download.csdn.net/detail/fengshuiyue/9844125