java lang nullpointerexception jsp

{ strfile = Request.getrealpath ("Count.txt"); float[][] xy = new FLOAT[4][2]; XY = Getnumandpercent (strfile); Int[] ang = new int[4]; ANG[0] = (int) (xy[0][1]*360); ANG[1] = (int) (xy[1][1]*360); ANG[2] = (int) (xy[2][1]*360); ANG[3] = 360-ang[0]-ang[1]-ang[2]; Response.setheader ("Cache-control", "No-store"); Response.setdateheader ("Expires", 0); Response.setcontenttype ("Image/jpeg"); Servletoutputstream Out=response.getoutputstream (); BufferedImage image=new bufferedimage (150,100,buff

I. Preface The original author of this article is Tony Wang. This article involves file read/write and automatic jpg image generation. Using JSP + Servlet technology, JSP calls servlet to generate images. Ii. index. jsp of the first file is as follows: Author: Tony Wang E-mail: lucky_tony@163.net Date: 2001-001 If you have any questions about the program, conta

I. Preparations before running Download the mysql jdbc Driver (a jar file) and load it in CLASSPATH (for the method, see one of the JAVA/JSP Learning Series (JDK installation). (If not found, download from this site) Create a MySQL database test The database has a table: note with the field name (varchar) Ii. Download and install Java. SQL. Statement sqlStmt;

used. Request is an implicit pre-defined object and does not need to be manually created in JSP code. JSP also contains the following implicit objects.1. application: The javax. servlet. servletcontext object obtained from the servlet configuration.2. Session: represents the javax. servlet. http. httpsession object.3. Request: represents the javax. servlet. httpservletrequest object.4. Response: represents

Article title: JSP, PHP, and JAVA integrated development environment (1 ). Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source. 　　 Preface This article introduces the establishment of a development environment integrating JSP, PHP,

How to configure struts4.0Step 1: Create a project. 2nd step: Create a webapplication by name (for example, book) and check jstl1.0 and struts1.1 (struts1.1) in the following selection basket. Press enter. 3rd step: Create a servlet in the Web selection item and add package to your desired package (such as PSL. ch1.ch2), and Class Name: chinafilter (whatever ). do not check two or more options in the middle. Select the filter servlet from the following single choice, then select the mapped servl

simpleuploaderservle is integrated into ororservlet, you do not need to configure file uploads and so on. net.fckeditor.connector.ConnectorServlet /fckeditor/editor/filemanager/connectors/* 5. Unzip the FCKeditor-java-demo-2.6.war, copy all jar packages under \ WEB-INF \ Lib \ to your project \ WEB-INF \ Lib. This step is very important. FCKeditor should use these jar files. 6. Create a directory under the

Original post address: Http://hi.baidu.com/huqiwen/blog/item/7d36b15113fddd1e377abe7d.html Because FCKeditor for Java 2.4 has made many changes compared with 2.3, these changes make it easier to configure FCKeditor. For example: Changed the base package name from Com. fredck. FCKeditorNet. FCKeditor. File Upload simpleuploaderservle is integrated into ororservlet. The web and xml configuration is much simpler. The following describes the configurati