index.jsp<\/p>\n
<%@page contentType=\"text\/html\" pageEncoding=\"UTF-8\"%>\r\n<!DOCTYPE html>\r\n<html>\r\n <head>\r\n <meta http-equiv=\"Content-Type\" content=\"text\/html; charset=UTF-8\">\r\n <title>Cubica<\/title>\r\n <\/head>\r\n <body>\r\n <h1>Cubica<\/h1>\r\n <p>y = a x\u00b3 + b x\u00b2 + c x + d<\/p>\r\n <form action=\"index.jsp\" method=\"get\">\r\n a = <input type=\"text\" name=\"a\"\/><br\/>\r\n b = <input type=\"text\" name=\"b\"\/><br\/>\r\n c = <input type=\"text\" name=\"c\"\/><br\/>\r\n d = <input type=\"text\" name=\"d\"\/><br\/>\r\n <input type=\"submit\" value=\"Disegna\" \/>\r\n <\/form>\r\n <p><img width=\"400\" height=\"400\" src=\"grafico?a=<%=request.getParameter(\"a\")%>&b=<%=request.getParameter(\"b\")%>&c=<%=request.getParameter(\"c\")%>&d=<%=request.getParameter(\"d\")%>\" \/><\/p>\r\n <\/body>\r\n<\/html><\/pre>\ngrafico.java<\/p>\n
double a = 0.0, b = 0.0, c = 0.0, d = 0.0;\r\n\r\nprivate double f(double x) {\r\n return a * x * x * x + b * x * x + c * x + d;\r\n}\r\n\r\nprivate int xg(double x) {\r\n return 200 + (int) Math.round(x * 40.0);\r\n}\r\n\r\nprivate int yg(double y) {\r\n return 200 - (int) Math.round(y * 40.0);\r\n}\r\n\r\nprotected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {\r\n response.setContentType(\"image\/png\");\r\n try (OutputStream os = response.getOutputStream()) {\r\n \/\/ crea l'immagine\r\n BufferedImage img = new BufferedImage(400, 400, BufferedImage.TYPE_INT_RGB);\r\n Graphics g = img.createGraphics();\r\n \/\/ cancella lo sfondo\r\n g.setColor(Color.WHITE);\r\n g.fillRect(0, 0, 400, 400);\r\n \/\/ disegna gli assi cartesiani\r\n g.setColor(Color.BLACK);\r\n g.drawLine(0, 200, 400, 200);\r\n g.drawString(\"X\", 390, 190);\r\n g.drawLine(200, 0, 200, 400);\r\n g.drawString(\"Y\", 210, 10);\r\n try {\r\n \/\/ legge i parametri\r\n a = Double.parseDouble(request.getParameter(\"a\"));\r\n b = Double.parseDouble(request.getParameter(\"b\"));\r\n c = Double.parseDouble(request.getParameter(\"c\"));\r\n d = Double.parseDouble(request.getParameter(\"d\"));\r\n \/\/ visualizza i parametri\r\n g.drawString(\"a = \" + a, 0, 20);\r\n g.drawString(\"b = \" + b, 0, 40);\r\n g.drawString(\"c = \" + c, 0, 60);\r\n g.drawString(\"d = \" + d, 0, 80);\r\n \/\/ disegna il grafico\r\n g.setColor(Color.BLUE);\r\n for (double x = -10.0; x < 10.0; x += 0.001) {\r\n double y = f(x);\r\n g.drawLine(xg(x), yg(y), xg(x), yg(y));\r\n }\r\n } catch (Exception e) {\r\n g.drawString(\"Alcuni parametri mancanti\", 0, 20);\r\n g.drawString(\"o non inseriti correttamente\", 0, 40);\r\n }\r\n \/\/ invia l'immagine in output\r\n ImageIO.write(img, \"png\", os);\r\n os.close();\r\n }\r\n}<\/pre>\n","protected":false},"excerpt":{"rendered":"index.jsp <%@page contentType=”text\/html” pageEncoding=”UTF-8″%> <!DOCTYPE html> <html> <head> <meta http-equiv=”Content-Type” content=”text\/html; charset=UTF-8″> <title>Cubica<\/title> <\/head> <body> <h1>Cubica<\/h1> <p>y = a x\u00b3 + b x\u00b2 + c x + d<\/p> <form action=”index.jsp” method=”get”> a = <input type=”text” name=”a”\/><br\/> b = <input type=”text” name=”b”\/><br\/> c = <input type=”text” name=”c”\/><br\/> d = <input type=”text” name=”d”\/><br\/> <input type=”submit” value=”Disegna” \/> … Continua a leggere Cubica<\/span><\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[],"class_list":["post-2318","post","type-post","status-publish","format-standard","hentry","category-informatica"],"_links":{"self":[{"href":"https:\/\/liceocuneo.it\/oddenino\/wp-json\/wp\/v2\/posts\/2318","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/liceocuneo.it\/oddenino\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/liceocuneo.it\/oddenino\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/liceocuneo.it\/oddenino\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/liceocuneo.it\/oddenino\/wp-json\/wp\/v2\/comments?post=2318"}],"version-history":[{"count":0,"href":"https:\/\/liceocuneo.it\/oddenino\/wp-json\/wp\/v2\/posts\/2318\/revisions"}],"wp:attachment":[{"href":"https:\/\/liceocuneo.it\/oddenino\/wp-json\/wp\/v2\/media?parent=2318"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/liceocuneo.it\/oddenino\/wp-json\/wp\/v2\/categories?post=2318"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/liceocuneo.it\/oddenino\/wp-json\/wp\/v2\/tags?post=2318"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}