[英]How import a .java file into a JSP page?
this is my first time trying to use java for backend web systems. 这是我第一次尝试将java用于后端Web系统。
I have been reading up some guides on how to do this, and thus far i understand the following points: 我一直在阅读一些关于如何做到这一点的指南,到目前为止我理解以下几点:
However, I am confused with a few things. 但是,我对一些事情感到困惑。
I now have a Dynamic Web Project, developing in Eclipse IDE and using TomCat7.0 apache. 我现在有一个动态Web项目,在Eclipse IDE中开发并使用TomCat7.0 apache。
I have a directory Java_Resources/src/somepackage/ 我有一个目录Java_Resources / src / somepackage /
and some .java files in the above directory. 和上面目录中的一些.java文件。
Question 1, in Eclipse, when I run these files, they are automatically compiled. 问题1,在Eclipse中,当我运行这些文件时,它们会自动编译。 Where does these class files go? 这些类文件在哪里?
Question 2, when I run the following code, I recieved some errors. 问题2,当我运行以下代码时,我收到了一些错误。 What am I doing wrong? 我究竟做错了什么? Is it because I do not have my class files in the right directory? 是因为我在正确的目录中没有我的类文件吗?
<%@ page language="java" import="twitter.*"%>
<%
JavaFile jf = new Javafile();
String result = jf.searchTweets("someString");
System.out.println(result);
%>
Error report: 错误报告:
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: An exception occurred processing JSP page /hello.jsp at line 10
7: <%@ page language="java" import="twitter.*"%>
8:
9: <%
10: Javafile jf = new JavaFile();
11:
12: String result = jf.searchTweets("someString");
13: System.out.println(result);
Thank you for your time and effort. 感谢您的时间和精力。
note: I have read the following links, but they do not seem to provide a solution on how to write your own .java files and import these classes into your jsp files. 注意:我已阅读以下链接,但它们似乎没有提供有关如何编写自己的.java文件并将这些类导入jsp文件的解决方案。
http://www.jsptut.com/ http://www.jsptut.com/
How do you import classes in JSP? 如何在JSP中导入类?
http://www.coderanch.com/t/288534/JSP/java/importing-class-file-jsp http://www.coderanch.com/t/288534/JSP/java/importing-class-file-jsp
EDIT: I found my own answer. 编辑:我找到了自己的答案。
This is my original directory 这是我原来的目录
As you can see, my WEB-INF/lib is empty. 如您所见,我的WEB-INF / lib是空的。
All that was required to do, is to move the relevant .jar files into this directory. 所需要做的就是将相关的.jar文件移动到此目录中。
Note: I have already imported the relevant .jar files to the Eclipse project, but it seems that I need to move them into WEB-INF/lib on top of importing them into the project. 注意:我已经将相关的.jar文件导入到Eclipse项目中,但似乎我需要将它们移动到WEB-INF / lib中,而不是将它们导入到项目中。
Thank you to all that helped answer my question. 感谢所有帮助回答我问题的人。
This is my final directory image 这是我的最终目录图片
Only classes may be imported into a .java
file, and a JSP "compiles" to a .java
file, so this requirement holds for JSP files too. 只有类可以导入到.java
文件中,并且JSP“编译”到.java
文件,因此这个要求也适用于JSP文件。
From a quick glance at the API, it seems that your import is formatted correctly; 从快速浏览API,您的导入似乎正确格式化; but, you are importing the wrong namespace. 但是,您导入的名称空间错误。 The javadoc for the twitter4j API indicates that you should be importing "twitter4j" namespaces, not "twitter" namespaces. twitter4j API的javadoc表示您应该导入“twitter4j”命名空间,而不是“twitter”命名空间。
Question 1, in Eclipse, when I run these files, they are automatically compiled. 问题1,在Eclipse中,当我运行这些文件时,它们会自动编译。 Where does these class files go? 这些类文件在哪里?
The class files go inside WEB-INF/classes
directory. 类文件位于WEB-INF/classes
目录中。
Question 2, when I run the following code, I recieved some errors. 问题2,当我运行以下代码时,我收到了一些错误。 What am I doing wrong? 我究竟做错了什么? Is it because I do not have my class files in the right directory? 是因为我在正确的目录中没有我的类文件吗?
Perhaps you have forgotten to put twitterXXX.jar
(or whatever it is called) into WEB-INF/lib
directory. 也许您忘记将twitterXXX.jar
(或其他任何名称)放入WEB-INF/lib
目录中。
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