檢視檔案源代碼功能實作

我們經常遇到，檢視檔案源代碼的功能。struts 自帶的例子是這樣的。

其中思路是這樣的：将檔案流轉換為list 輸出出來。

用到了

第一種：讀取class

inputstream in = getclass().getresourceasstream(classname);

第二種：一般檔案

inputstream in = classloaderutil.getresourceasstream(page.substring(indexof+1), getclass()); 

//or 

    in = servletcontext.getresourceasstream(page);

第三種：配置檔案

new url(config).openstream()

/* 

* $id: viewsourceaction.java 570518 2007-08-28 18:26:48z jholmes $ 

* 

* licensed to the apache software foundation (asf) under one 

* or more contributor license agreements.    see the notice file 

* distributed with this work for additional information 

* regarding copyright ownership.    the asf licenses this file 

* to you under the apache license, version 2.0 (the 

* "license"); you may not use this file except in compliance 

* with the license.    you may obtain a copy of the license at 

*    http://www.apache.org/licenses/license-2.0 

* unless required by applicable law or agreed to in writing, 

* software distributed under the license is distributed on an 

* "as is" basis, without warranties or conditions of any 

* kind, either express or implied.    see the license for the 

* specific language governing permissions and limitations 

* under the license. 

*/ 

package org.apache.struts2.showcase.source; 

import java.io.bufferedreader; 

import java.io.ioexception; 

import java.io.inputstream; 

import java.io.inputstreamreader; 

import java.net.malformedurlexception; 

import java.net.url; 

import java.util.arraylist; 

import java.util.list; 

import javax.servlet.servletcontext; 

import javax.servlet.http.httpservletrequest; 

import org.apache.struts2.servletactioncontext; 

import org.apache.struts2.util.servletcontextaware; 

import com.opensymphony.xwork2.actionsupport; 

import com.opensymphony.xwork2.util.classloaderutil; 

/** 

* processes configuration, page, and action class paths to create snippets 

* of the files for display. 

public class viewsourceaction extends actionsupport implements servletcontextaware { 

        private string page; 

        private string classname; 

        private string config; 

        /** 

         * 資料行清單 

         */ 

        private list pagelines; 

        private list classlines; 

        private list configlines; 

        private int configline; 

        private int padding = 10; 

        private servletcontext servletcontext; 

        public string execute() throws malformedurlexception, ioexception { 

                if (page != null && page.trim().length() > 0) { 

                        int indexof = page.indexof("//"); 

      inputstream in = classloaderutil.getresourceasstream(page.substring(indexof+1), getclass()); 

                        page = page.replace("//", "/"); 

                        if (in == null) { 

                                in = servletcontext.getresourceasstream(page); 

                                while (in == null && page.indexof('/', 1) > 0) { 

                                        page = page.substring(page.indexof('/', 1)); 

                                        in = servletcontext.getresourceasstream(page); 

                                } 

                        } 

                        pagelines = read(in, -1); 

                        if (in != null) { 

                                in.close(); 

                } 

                if (classname != null && classname.trim().length() > 0) { 

                        classname = "/"+classname.replace('.', '/') + ".java"; 

                        inputstream in = getclass().getresourceasstream(classname); 

                                in = servletcontext.getresourceasstream("/web-inf/src"+classname); 

                        classlines = read(in, -1); 

                string rootpath = servletactioncontext.getservletcontext().getrealpath("/"); 

                if (config != null && config.trim().length() > 0 && (rootpath == null || config.startswith(rootpath))) { 

                        int pos = config.lastindexof(':'); 

                        configline = integer.parseint(config.substring(pos+1)); 

                        config = config.substring(0, pos).replace("//", "/"); 

                        configlines = read(new url(config).openstream(), configline); 

                return success; 

        } 

         * @param classname the classname to set 

        public void setclassname(string classname) { 

                this.classname = classname; 

         * @param config the config to set 

        public void setconfig(string config) { 

                this.config = config; 

         * @param page the page to set 

        public void setpage(string page) { 

                this.page = page; 

         * @param padding the padding to set 

        public void setpadding(int padding) { 

                this.padding = padding; 

         * @return the classlines 

        public list getclasslines() { 

                return classlines; 

         * @return the configlines 

        public list getconfiglines() { 

                return configlines; 

         * @return the pagelines 

        public list getpagelines() { 

                return pagelines; 

         * @return the classname 

        public string getclassname() { 

                return classname; 

         * @return the config 

        public string getconfig() { 

                return config; 

         * @return the page 

        public string getpage() { 

                return page; 

         * @return the configline 

        public int getconfigline() { 

                return configline; 

         * @return the padding 

        public int getpadding() { 

                return padding; 

         * reads in a strea, optionally only including the target line number 

         * and its padding 

         * 

         * @param in the input stream 

         * @param targetlinenumber the target line number, negative to read all 

         * @return a list of lines 

        private list read(inputstream in, int targetlinenumber) { 

                list snippet = null; 

                if (in != null) { 

                        snippet = new arraylist(); 

                        int startline = 0; 

                        int endline = integer.max_value; 

                        if (targetlinenumber > 0) { 

                                startline = targetlinenumber - padding; 

                                endline = targetlinenumber + padding; 

                        try { 

                                bufferedreader reader = new bufferedreader(new inputstreamreader(in)); 

                                int lineno = 0; 

                                string line; 

                                while ((line = reader.readline()) != null) { 

                                        lineno++; 

                                        if (lineno >= startline && lineno <= endline) { 

                                                snippet.add(line); 

                                        } 

                        } catch (exception ex) { 

                                // ignoring as snippet not available isn't a big deal 

                return snippet; 

        public void setservletcontext(servletcontext arg0) { 

                this.servletcontext = arg0; 

}