他在那里,
现在被卡住了一段时间.我试图做的事情归结为:
been stuck for a while now. What im trying to do comes down to this:
- 我已经开发了一个小库,正在以jar文件的形式进行部署.它包含一个我需要访问的文件,该文件位于"json2/json.js"中(是,doin jscript/rhino东西)
- 我将jar文件导入到经典的Java项目中,效果很好.找到文件并读取
- 我将SAME jar文件导入到tomcat-project中,如下所示:
- 调用Java类的.jsp
- 我在我的类库中调用了我的库,该库位于tomcat/lib目录中
- 现在当我尝试访问我无法访问的文件时(空指针)
- I have developed a little library which i am deploying in form of a jar-file. it contains a file i need to access, which is located in "json2/json.js" (yep, doin jscript/rhino things)
- I import the jar-file into a classical java-project, it works fine. File is found and read
- I import the SAME jar-file into tomcat-project which looks as follows:
- a .jsp that calls a java-class
- inside the java-class i call my library, which is located in the tomcat/lib-directory
- now when i try to access the file i cant (null-pointer)
来源:
InputStream in = ClassLoader.getSystemResourceAsStream("json2/json.js");当我在tomcat中运行它时(in == null).
when i run it inside the tomcat, (in==null).
为了诊断,我即兴以下内容:
for diagnosis i improvised the following:
File fu = new File(new URI(this.getClass().getClassLoader().getResource("").toString())); String[] l = fu.list(); for (int i = 0; i < l.length; i++) { System.out.println(i+"||"+l[i]); }使用经典的Java类,它仅生成我的main-class-file.在tomcat中,它向我显示了"tomcat/lib"目录的内容.
with the classic java-class it only produces my main-class-file. in tomcat it shows me the content of the "tomcat/lib"-directory.
有什么想法吗?将不胜感激...
any ideas? would be greatly appreciated...
编辑
我忘记添加的一个细节(确实磨碎了我的装备)
one detail that i forgot to add (and that really grinds my gears):
SParser.class.getClassLoader().getParent().getResource("")出现一个null-ptr. wtf?我没有访问特定的资源,仍然没有结果.
comes up with a null-ptr. wtf? im not accessing a particular ressource, still no result.
推荐答案请勿使用getSystemResourceAsStream().使用getResourceAsStream().在Tomcat webapp环境中,系统类加载器不了解Tomcat/lib也不了解webapp库.
Do not use getSystemResourceAsStream(). Use getResourceAsStream(). On a Tomcat webapp environment, the system classloader has no knowledge of Tomcat/lib nor the webapp libraries.
另外,在抓取ClassLoader时,您最好抓取当前线程的上下文类加载器.
Also, when grabbing the ClassLoader, you should preferably grab the context class loader of the current thread.
ClassLoader classLoader = Thread.currentThread().getContextClassLoader(); InputStream inputStream = classLoader.getResourceAsStream("/json/json.js");更多推荐
从tomcat访问jar文件
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