The host and the middle man<\/h2>\n\r\n<?xml version="1.0" encoding="UTF-8"?>\r\n<!DOCTYPE html PUBLIC "-\/\/W3C\/\/DTD XHTML 1.0 Strict\/\/EN" \r\n "http:\/\/www.w3.org\/TR\/xhtml1\/DTD\/xhtml1-strict.dtd">\r\n<html xmlns="http:\/\/www.w3.org\/1999\/xhtml" xml:lang="en" lang="en">\r\n<head>\r\n <title>Sending message from Java applet to web page via jQuery - Proof Of Concepts<\/title>\r\n <script src="\/\/ajax.googleapis.com\/ajax\/libs\/jquery\/1.10.2\/jquery.min.js"><\/script>\r\n<\/head>\r\n<body>\r\n <h4>Message from applet:<\/h4>\r\n\t<div id="containerToWriteTo">\r\n\t\t\r\n\t<\/div>\r\n\t\r\n\t<h4>The applet<\/h4>\r\n\t<applet name="MessageSendingApplet" \r\n\t\t\tcode="com\/techcoil\/applet\/send\/message\/to\/webpage\/MessageSendingApplet.class" \r\n\t\t\tarchive="http:\/\/www.techcoil.com\/resource\/java\/applet\/MessageSendingApplet.jar" \r\n\t\t\theight="45"\r\n\t\t\twidth="350">\r\n\t<p>You have to activate Java in order to view this proof of concept<\/p>\r\n\t<\/applet>\r\n\t\r\n\t<script type="text\/javascript">\r\n\t\tfunction writeToContainer(msg) {\r\n\t\t\t$('#containerToWriteTo').html(msg);\r\n\t\t}\r\n\t<\/script>\r\n<\/body>\r\n<\/html>\r\n<\/pre>\nIn the body<\/code> tag, I define a div<\/code> section to hold the message from the applet and identified it as containerToWriteTo<\/code>. <\/p>\nI then use the applet<\/code> tag to hold the applet that I am going to create.<\/p>\nLastly, near the closing body<\/code> tag, I define the writeToContainer<\/code> Javascript function with an input parameter msg. In the function, I use jQuery<\/a> to look for the containerToWriteTo<\/code> div<\/strong> and set its content with whatever that is passed into the function via the msg<\/code> parameter.<\/p>\nThe Java applet<\/h2>\nPre compilation work<\/h3>\n
The netscape.javascript.JSObject<\/code><\/a> class is needed for my Java applet to call some Javascript functions that is contained in the same webpage where it is embedded at. <\/p>\nAnd for my Java applet to be compiled successfully while it uses JSObject<\/code>, I will need to specify the plugin.jar<\/strong> library found in the \/lib folder in the build path.<\/p>\nThe Java codes to realise the applet<\/h3>\n\r\npackage com.techcoil.applet.send.message.to.webpage;\r\n\r\nimport java.awt.Dimension;\r\nimport java.awt.event.ActionEvent;\r\nimport java.awt.event.ActionListener;\r\n\r\nimport javax.swing.JApplet;\r\nimport javax.swing.JButton;\r\nimport javax.swing.JOptionPane;\r\nimport javax.swing.JPanel;\r\nimport javax.swing.JTextField;\r\nimport javax.swing.SwingUtilities;\r\n\r\nimport netscape.javascript.JSException;\r\nimport netscape.javascript.JSObject;\r\n\r\npublic class MessageSendingApplet extends JApplet {\r\n\r\n\tprivate static final long serialVersionUID = 1L;\r\n\t\r\n\tprivate JButton sendMessageButton;\r\n\tprivate JTextField messageTf;\r\n\tprivate JSObject browserWindow;\r\n\t\r\n\tpublic void init() {\r\n\t\tSwingUtilities.invokeLater(new Runnable() {\r\n\t\t public void run() {\r\n\t\t \tinitApplet();\r\n\t\t }\r\n\t\t});\r\n\t}\r\n\t\r\n\tprivate void initApplet() {\r\n\t\t\r\n\t\tthis.setSize(new Dimension(350, 45));\r\n\t\t\t\r\n\t\tJPanel mainPane = new JPanel();\r\n\t\t\r\n\t\tActionListener submitMessageActionListener = new ActionListener() {\r\n\t\t\t\r\n\t\t\tpublic void actionPerformed (ActionEvent e) {\r\n\t\t\t\tsendMessageToWebpage();\r\n\t\t\t}\r\n\t\t\t\r\n\t\t};\r\n\t\t\r\n\t\tthis.messageTf = new JTextField();\r\n\t\tthis.messageTf.setPreferredSize(new Dimension(200, 30));\r\n\t\tthis.messageTf.setMinimumSize(new Dimension(80, 30));\r\n\t\tthis.messageTf.addActionListener(submitMessageActionListener);\r\n\t\t\r\n\t\tthis.sendMessageButton = new JButton("Send message");\r\n\t\tthis.sendMessageButton.setToolTipText("Send the message in the text field to the web page.");\r\n\t\tthis.sendMessageButton.setPreferredSize(new Dimension(120, 29));\r\n\t\tthis.sendMessageButton.addActionListener(submitMessageActionListener);\r\n\t\t\r\n\t\tmessageTf.requestFocus();\r\n\t\t\r\n\t\tmainPane.add(messageTf);\r\n\t\tmainPane.add(sendMessageButton);\r\n\t\t\r\n\t\tsetContentPane(mainPane);\r\n\t\t\r\n\t\ttry {\r\n\t\t\tbrowserWindow = JSObject.getWindow(this);\r\n\t\t} catch(JSException jse) {\r\n\t\t\tthis.displayErrorMessage("Unable to get a reference to the browser window.");\r\n\t\t}\r\n\t}\r\n\t\r\n\tprivate void sendMessageToWebpage() {\r\n\t\tif (this.browserWindow != null) {\r\n\t\t\ttry {\r\n\t\t\t\tbrowserWindow.eval("writeToContainer('" + this.messageTf.getText() + "')");\r\n\t\t\t}\r\n\t\t\tcatch (JSException jse) {\r\n\t\t\t\tthis.displayErrorMessage(jse.getMessage());\r\n\t\t\t} \/\/ end try-catch\r\n\t\t}\r\n\t\telse {\r\n\t\t\tthis.displayErrorMessage("Unable to get a reference to browser window.");\r\n\t\t}\r\n\t}\r\n\t\r\n\tprivate void displayErrorMessage(String msg) {\r\n\t\tJOptionPane.showMessageDialog(this, \r\n\t\t\t\tmsg, \r\n\t\t\t\t"Message Sending Applet",\r\n\t\t\t\tJOptionPane.ERROR_MESSAGE);\r\n\t}\r\n\t\r\n}\r\n<\/pre>\nBuilding the applet user interface<\/h3>\n
I started building the code by extending a subclass from the javax.swing.JApplet<\/code><\/a> class. I gave life to the applet by overriding the init() function. I then use the SwingUtilities.invokeLater<\/code><\/a> function to ensure that the applet was created by the AWT event dispatch thread.<\/p>\nWithin the initApplet<\/code> method, I create the user interface components for the applet to interact with the user:<\/p>\n\n- A text field to collect messages from the user <\/li>\n
- A button for the user to submit the messages<\/li>\n
- A action handler that sends messages from the text field to the web page<\/li>\n<\/ul>\n
Lastly, I get a reference to the Javascript window object for the HTML document via the JSObject.getObject<\/code> function and remembers it with the browserWindow<\/code> variable.<\/p>\nSending the message to the web page<\/h3>\n
When the user press enter or click on the \"Send message\" button, the sendMessageToWebpage<\/code> method will be called. In the sendMessageToWebpage<\/code> method, I use the JSObject.eval<\/code> method to invoke the middle man function, passing it the text value that I get from the text field.<\/p>\n\n See this proof of concept<\/a>\n<\/div>\n\n \n - \n \n
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Save\n <\/a>\n <\/li>\n <\/ul>\n ","protected":false},"excerpt":{"rendered":"In an attempt to save development time on reworking the RIAs from a old system, a business decision was made to reuse the Java applets on a newer system. <\/p>\n
The newer system utilizes jQuery at the front end to fulfill modern user interactivity requirements. <\/p>\n
This post documents a proof of concept that I did for the powerful Java applets to communicate with the front-end of the newer system.<\/p>\n","protected":false},"author":1,"featured_media":1220,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":true,"_jetpack_newsletter_tier_id":0,"footnotes":""},"categories":[375],"tags":[16,137,6,162,128,89],"jetpack_featured_media_url":"https:\/\/www.techcoil.com\/blog\/wp-content\/uploads\/Java-logo.gif","jetpack_shortlink":"https:\/\/wp.me\/p245TQ-4T","jetpack-related-posts":[],"jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/posts\/303"}],"collection":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/comments?post=303"}],"version-history":[{"count":0,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/posts\/303\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/media\/1220"}],"wp:attachment":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/media?parent=303"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/categories?post=303"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/tags?post=303"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
In the I then use the Lastly, near the closing The And for my Java applet to be compiled successfully while it uses I started building the code by extending a subclass from the Within the Lastly, I get a reference to the Javascript window object for the HTML document via the When the user press enter or click on the \"Send message\" button, the In an attempt to save development time on reworking the RIAs from a old system, a business decision was made to reuse the Java applets on a newer system. <\/p>\n The newer system utilizes jQuery at the front end to fulfill modern user interactivity requirements. <\/p>\n This post documents a proof of concept that I did for the powerful Java applets to communicate with the front-end of the newer system.<\/p>\n","protected":false},"author":1,"featured_media":1220,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":true,"_jetpack_newsletter_tier_id":0,"footnotes":""},"categories":[375],"tags":[16,137,6,162,128,89],"jetpack_featured_media_url":"https:\/\/www.techcoil.com\/blog\/wp-content\/uploads\/Java-logo.gif","jetpack_shortlink":"https:\/\/wp.me\/p245TQ-4T","jetpack-related-posts":[],"jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/posts\/303"}],"collection":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/comments?post=303"}],"version-history":[{"count":0,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/posts\/303\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/media\/1220"}],"wp:attachment":[{"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/media?parent=303"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/categories?post=303"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.techcoil.com\/blog\/wp-json\/wp\/v2\/tags?post=303"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}body<\/code> tag, I define a div<\/code> section to hold the message from the applet and identified it as containerToWriteTo<\/code>. <\/p>\napplet<\/code> tag to hold the applet that I am going to create.<\/p>\nbody<\/code> tag, I define the writeToContainer<\/code> Javascript function with an input parameter msg. In the function, I use jQuery<\/a> to look for the containerToWriteTo<\/code> div<\/strong> and set its content with whatever that is passed into the function via the msg<\/code> parameter.<\/p>\nThe Java applet<\/h2>\n
Pre compilation work<\/h3>\n
netscape.javascript.JSObject<\/code><\/a> class is needed for my Java applet to call some Javascript functions that is contained in the same webpage where it is embedded at. <\/p>\nJSObject<\/code>, I will need to specify the plugin.jar<\/strong> library found in the \/lib folder in the build path.<\/p>\nThe Java codes to realise the applet<\/h3>\n
\r\npackage com.techcoil.applet.send.message.to.webpage;\r\n\r\nimport java.awt.Dimension;\r\nimport java.awt.event.ActionEvent;\r\nimport java.awt.event.ActionListener;\r\n\r\nimport javax.swing.JApplet;\r\nimport javax.swing.JButton;\r\nimport javax.swing.JOptionPane;\r\nimport javax.swing.JPanel;\r\nimport javax.swing.JTextField;\r\nimport javax.swing.SwingUtilities;\r\n\r\nimport netscape.javascript.JSException;\r\nimport netscape.javascript.JSObject;\r\n\r\npublic class MessageSendingApplet extends JApplet {\r\n\r\n\tprivate static final long serialVersionUID = 1L;\r\n\t\r\n\tprivate JButton sendMessageButton;\r\n\tprivate JTextField messageTf;\r\n\tprivate JSObject browserWindow;\r\n\t\r\n\tpublic void init() {\r\n\t\tSwingUtilities.invokeLater(new Runnable() {\r\n\t\t public void run() {\r\n\t\t \tinitApplet();\r\n\t\t }\r\n\t\t});\r\n\t}\r\n\t\r\n\tprivate void initApplet() {\r\n\t\t\r\n\t\tthis.setSize(new Dimension(350, 45));\r\n\t\t\t\r\n\t\tJPanel mainPane = new JPanel();\r\n\t\t\r\n\t\tActionListener submitMessageActionListener = new ActionListener() {\r\n\t\t\t\r\n\t\t\tpublic void actionPerformed (ActionEvent e) {\r\n\t\t\t\tsendMessageToWebpage();\r\n\t\t\t}\r\n\t\t\t\r\n\t\t};\r\n\t\t\r\n\t\tthis.messageTf = new JTextField();\r\n\t\tthis.messageTf.setPreferredSize(new Dimension(200, 30));\r\n\t\tthis.messageTf.setMinimumSize(new Dimension(80, 30));\r\n\t\tthis.messageTf.addActionListener(submitMessageActionListener);\r\n\t\t\r\n\t\tthis.sendMessageButton = new JButton("Send message");\r\n\t\tthis.sendMessageButton.setToolTipText("Send the message in the text field to the web page.");\r\n\t\tthis.sendMessageButton.setPreferredSize(new Dimension(120, 29));\r\n\t\tthis.sendMessageButton.addActionListener(submitMessageActionListener);\r\n\t\t\r\n\t\tmessageTf.requestFocus();\r\n\t\t\r\n\t\tmainPane.add(messageTf);\r\n\t\tmainPane.add(sendMessageButton);\r\n\t\t\r\n\t\tsetContentPane(mainPane);\r\n\t\t\r\n\t\ttry {\r\n\t\t\tbrowserWindow = JSObject.getWindow(this);\r\n\t\t} catch(JSException jse) {\r\n\t\t\tthis.displayErrorMessage("Unable to get a reference to the browser window.");\r\n\t\t}\r\n\t}\r\n\t\r\n\tprivate void sendMessageToWebpage() {\r\n\t\tif (this.browserWindow != null) {\r\n\t\t\ttry {\r\n\t\t\t\tbrowserWindow.eval("writeToContainer('" + this.messageTf.getText() + "')");\r\n\t\t\t}\r\n\t\t\tcatch (JSException jse) {\r\n\t\t\t\tthis.displayErrorMessage(jse.getMessage());\r\n\t\t\t} \/\/ end try-catch\r\n\t\t}\r\n\t\telse {\r\n\t\t\tthis.displayErrorMessage("Unable to get a reference to browser window.");\r\n\t\t}\r\n\t}\r\n\t\r\n\tprivate void displayErrorMessage(String msg) {\r\n\t\tJOptionPane.showMessageDialog(this, \r\n\t\t\t\tmsg, \r\n\t\t\t\t"Message Sending Applet",\r\n\t\t\t\tJOptionPane.ERROR_MESSAGE);\r\n\t}\r\n\t\r\n}\r\n<\/pre>\nBuilding the applet user interface<\/h3>\n
javax.swing.JApplet<\/code><\/a> class. I gave life to the applet by overriding the init() function. I then use the SwingUtilities.invokeLater<\/code><\/a> function to ensure that the applet was created by the AWT event dispatch thread.<\/p>\ninitApplet<\/code> method, I create the user interface components for the applet to interact with the user:<\/p>\n\n
JSObject.getObject<\/code> function and remembers it with the browserWindow<\/code> variable.<\/p>\nSending the message to the web page<\/h3>\n
sendMessageToWebpage<\/code> method will be called. In the sendMessageToWebpage<\/code> method, I use the JSObject.eval<\/code> method to invoke the middle man function, passing it the text value that I get from the text field.<\/p>\n\n
Share\n <\/a>\n <\/li>\n Tweet\n <\/a>\n <\/li>\n Share\n <\/a>\n <\/li>\n Save\n <\/a>\n <\/li>\n <\/ul>\n ","protected":false},"excerpt":{"rendered":"