XULRunner with Java: JavaXPCOM Tutorial 5

7.3 点击Element和填写表单
    我们可以安全的加载页面，抽取信息，但是有时浏览网页是需要填写表单并提交或者点击某个元素来触发onclick以便执行一段

JavaScript代码。
    嗯，要想点击一个element需要获得这个element(前面的xpathNodes也许可以帮我们做到这点)，如果是input element，我们需

要调用它的submit方法，如果是anchor的话，我们家需要访问它的href里的url。如果这个元素有onclick属性，这段脚本必需首先被

执行。
    填写text field，需要修改DOM tree，设置属性的值(比如HTMLInputElement)或者插入一个文本子节点(比如

HTMLTextAreaElement)。看看下面的例子就会发现这并不困难。

    译注：主要有2个方法 enter 和 click。
    enter给text和textArea设置值，text直接设置value属性就行了，而textArea先要删除所有子节点，然后增加一个新的text

node来包含我们想要输入的内容。
    click点击一个元素，比如element, anchor submit按钮等等。

 

package es.ladyr.javaxpcom.browser;  
import java.util.ArrayList;  
import java.util.List;  
import java.util.concurrent.CountDownLatch;  
import java.util.concurrent.TimeUnit;  
import org.eclipse.swt.SWT;  
import org.eclipse.swt.SWTError;  
import org.eclipse.swt.browser.Browser;  
import org.eclipse.swt.browser.ProgressEvent;  
import org.eclipse.swt.browser.ProgressListener;  
import org.eclipse.swt.widgets.Display;  
import org.eclipse.swt.widgets.Shell;  
import org.mozilla.dom.html.HTMLDocumentImpl;  
import org.mozilla.dom.NodeFactory;  
import org.mozilla.interfaces.nsIComponentManager;  
import org.mozilla.interfaces.nsIDOMDocument;  
import org.mozilla.interfaces.nsIDOMHTMLDocument;  
import org.mozilla.interfaces.nsIDOMNode;  
import org.mozilla.interfaces.nsIDOMWindow;  
import org.mozilla.interfaces.nsIDOMXPathEvaluator;  
import org.mozilla.interfaces.nsIDOMXPathNSResolver;  
import org.mozilla.interfaces.nsIDOMXPathResult;  
import org.mozilla.interfaces.nsISupports;  
import org.mozilla.interfaces.nsIWebBrowser;  
import org.mozilla.xpcom.Mozilla;  
import org.w3c.dom.DOMException;  
import org.w3c.dom.Node;  
import org.w3c.dom.NodeList;  
import org.w3c.dom.html.HTMLAnchorElement;  
import org.w3c.dom.html.HTMLDocument;  
import org.w3c.dom.html.HTMLElement;  
import org.w3c.dom.html.HTMLFormElement;  
import org.w3c.dom.html.HTMLInputElement;  
import org.w3c.dom.html.HTMLTextAreaElement;  
public class SimpleBrowserWithClick {  
          
        private final static String NS_IDOMXPATHEVALUATOR_CONTRACTID = "@mozilla.org/dom/xpath-evaluator;1";  
          
        private Browser browser;  
          
        // We will need SWT display to execute methods  
        // into the SWT event thread.  
        private Display display;  
          
        // Latch used to manage page loading  
        // Uses a count of 1, so when the browser starts loading  
        // a page, we create a new latch, which will be   
        // decremented when the page is loaded.  
        private CountDownLatch latch;  
          
        // Default timeout to 60 seconds  
        private long defaultTimeout = 60000;  
          
        // XPath evaluator  
        private nsIDOMXPathEvaluator xpathEval;  
        /** 
         * Creates a web browser which is able to load pages waiting until 
         * the page is completely loaded and solve xpaths returning 
         * the corresponding nodes. 
         * 
         */  
        public SimpleBrowserWithClick (final String xulrunnerPath) {  
                  
                // Use a latch to wait for the browser initialization.  
                final CountDownLatch initLatch = new CountDownLatch(1);  
                  
                // MozillaBrowser needs a window manager to work. We are using SWT  
                // for the graphical interface, so we need to execute MozillaBrowser  
                // methods into the SWT event thread. If we were use another thread,  
                // that methods could not work properly and throw an exception,  
                // breaking the execution flow and crashing our application.  
                new Thread("SWT-Event-Thread") {  
                        @Override  
                        public void run() {  
                                display = new Display();  
                                Shell shell = new Shell(display);  
                                shell.setSize(800, 600);  
                                shell.open();  
                                // If you have XULRunner installed, you can call the constructor without  
                                // the last parameter:  
                                //  
                                // final MozillaBrowser browser = new MozillaBrowser(shell,SWT.BORDER);  
                                //  
                                // That last parameter is the path for XULRunner files  
                                // (where you have uncompressed downloaded XULRunner package).  
                                try {  
                                                browser = new Browser(shell, SWT.MOZILLA);  
                                        } catch (SWTError e) {  
                                                System.out.println("Could not instantiate Browser: " + e.getMessage  
());  
                                                return;  
                                        }  
                                  
                                  
                                // Adapt browser size to shell size  
                                browser.setBounds(shell.getClientArea());  
                                  
                                // Listens for page loading status.  
                                browser.addProgressListener(new ProgressListener() {  
                                        public void changed(ProgressEvent event) {  
                                        }  
                                        public void completed(ProgressEvent event) {  
                                                // When a page is loaded, decrement the latch,  
                                                // which count will be 0 after this call.  
                                                latch.countDown();  
                                        }  
                                });  
                                  
                                // Realease the initialization latch, which has value 1,  
                                // so after this call its value will be 0.  
                                initLatch.countDown();  
                                  
                                while (!shell.isDisposed()) {  
                                        if (!display.readAndDispatch()) {  
                                                display.sleep();  
                                        }  
                                }  
                                System.exit(0);  
                        }  
                }.start();  
                  
                try {  
                        // Waits until the initialization latch is released.  
                        initLatch.await();  
                } catch (InterruptedException e) {  
                        Thread.interrupted();  
                }  
                  
                // Creates the XPath evaluator XPCOM component  
                Mozilla moz = Mozilla.getInstance();  
                nsIComponentManager componentManager = moz.getComponentManager();  
                xpathEval = (nsIDOMXPathEvaluator) componentManager.createInstanceByContractID(  
                                                NS_IDOMXPATHEVALUATOR_CONTRACTID, null,   
nsIDOMXPathEvaluator.NS_IDOMXPATHEVALUATOR_IID);  
                  
        }  
          
        /** 
         * Loads an URL into the browser and waits until the page is 
         * totally loaded. 
         * @param url 
         * @throws SimpleBrowserException 
         */  
        public void go(final String url) throws SimpleBrowserException {  
                  
                // Creates a latch with count 1  
                latch = new CountDownLatch(1);  
                // Uses the SWT event thread to execute the method to  
                // load an URL in the browser.  
                display.syncExec(new Runnable() {  
                        public void run() {  
                                browser.setUrl(url);  
                        }  
                });  
                  
                // Waits for the finish of the page loading, or for a given  
                // timeout in case that the loading doesn't finish in a   
                // reasonable time.  
                boolean timeout = waitLoad(defaultTimeout);  
                if (timeout) {  
                        throw new SimpleBrowserException("Timeout waiting page loading.");  
                }  
        }  
          
        /** 
         *  
         * @return      an W3C HTML Document implementation corresponding to 
         *      the Mozilla DOM HTML document currently loaded in the browser. 
         * @throws SimpleBrowserException 
         */  
          
          
        public HTMLDocument getW3CDocument() {  
              
                                                  
                                class DocumentGetter implements Runnable {  
                                        private nsIDOMHTMLDocument htmldoc;  
                                                public void run(){  
                                nsIWebBrowser webBrowser = (nsIWebBrowser)browser.getWebBrowser();  
                                        if (webBrowser == null) {  
                                                System.out.println("Could not get the nsIWebBrowser from the Browser   
widget");  
                                        }         
                          
                                        nsIDOMWindow dw = webBrowser.getContentDOMWindow();  
                                nsIDOMDocument nsDoc = dw.getDocument();  
                                htmldoc = (nsIDOMHTMLDocument) nsDoc  
                                                                                .queryInterface  
(nsIDOMHTMLDocument.NS_IDOMHTMLDOCUMENT_IID);  
                                  
                                }  
                                                public nsIDOMHTMLDocument getHtmldoc() {  
                                                        return htmldoc;  
                                                }}  
                                  
                                DocumentGetter dg = new DocumentGetter();  
                                  
                                display.syncExec(dg);  
                                  
                                return HTMLDocumentImpl.getDOMInstance(dg.getHtmldoc());  
                        }  
          
        /** 
         *  
         * @param xpath 
         * @return      a list with the nodes corresponding to a given xpath. 
         * @throws SimpleBrowserException 
         */  
        public List<Node> xpathNodes(String xpath) {  
                  
                return xPathNodes(xpath,   
                                ((HTMLDocumentImpl) getW3CDocument()).getInstance());             
        }  
          
        /** 
         *  
         * @param <T> 
         * @param xpath 
         * @param nodeClass 
         * @return      a list of <code>nodeClass</code> nodes corresponding 
         *      to a given xpath. 
         * @throws SimpleBrowserException 
         */  
        public <T extends Node> List<T> xpathNodes(String xpath, Class<T> nodeClass) {  
                  
                  
                return (List<T>)xPathNodes(xpath,  
                    ((HTMLDocumentImpl) getW3CDocument()).getInstance());  
                  
        }         
        /** 
         * Enters the given text in a W3C input node. If the node is not 
         * a HTMLInputElement or a HTMLTextAreaElement instance, then 
         * a exception is thrown. 
         *  
         * @param node 
         * @param text 
         * @throws SimpleBrowserException 
         */  
        public void enter(final Node node, final String text) throws SimpleBrowserException {  
                if (node instanceof HTMLInputElement) {  
                        HTMLInputElement textComponent = (HTMLInputElement) node;  
                        enter(textComponent, text);  
                } else if (node instanceof HTMLTextAreaElement) {  
                        HTMLTextAreaElement textComponent = (HTMLTextAreaElement) node;  
                        enter(textComponent, text);  
                } else {  
                        throw new SimpleBrowserException(  
                                        "enter only works with textfield (HTMLInputElement) or textarea   
(HTMLTextAreaElement)");  
                }  
        }  
        /** 
         * Enters the given text in a HTMLInputElement. If text is  
         * <code>null</code>, then an empty string will be inserted.  
         *  
         * @param inputElement 
         * @param text 
         * @throws SimpleBrowserException 
         */  
        public void enter(final HTMLInputElement inputElement, String text) {  
                  
                final String inputText;  
                if (text == null) {  
                        inputText = "";  
                } else {  
                        inputText = text;  
                }  
                display.syncExec(new Runnable() {  
                        public void run() {  
                                inputElement.setValue(inputText);  
                        }  
                });  
        }  
        /** 
         * Enters the given text in a HTMLTextAreaElement. If text is  
         * <code>null</code>, then an empty string will be inserted.  
         *  
         * @param textArea 
         * @param text 
         * @throws SimpleBrowserException 
         */  
        public void enter(final HTMLTextAreaElement textArea, String text) {  
                  
                final String inputText;  
                if (text == null) {  
                        inputText = "";  
                } else {  
                        inputText = text;  
                }  
                display.syncExec(new Runnable() {  
                        public void run() {  
                                // Empty the text area  
                                NodeList nodeList = textArea.getChildNodes();  
                                for (int i = 0; i < nodeList.getLength(); i++) {  
                                        textArea.removeChild(nodeList.item(i));  
                                }  
                                  
                                // Fill the text area with a new text node containing the given text  
                                try {  
                                        textArea.appendChild(getW3CDocument().createTextNode(inputText));  
                                          
                                } catch (DOMException e) {  
                                        System.err.println("Problems inserting the new child node.");  
                                        e.printStackTrace();  
                                          
                                }  
                        }  
                });  
        }  
          
        /** 
         * Clicks on a W3C node. If the HTML element has an attribute 'oncllick', 
         * first try to execute the script and then click the element. If the node 
         * is not an instance of HTMLInputElement, HTMLAnchorElement or HTMLElement, 
         * then an exception will be thrown. 
         *  
         * @param node 
         * @throws SimpleBrowserException 
         */  
        public void click(Node node) throws SimpleBrowserException {  
                  
                // If the node is a instance of HTMLElement and contains an  
                // 'onclick' attribute, then we must execute the script  
                if ( node instanceof HTMLElement ){                       
                        final HTMLElement ele = (HTMLElement) node;   
                          
                        display.syncExec(new Runnable() {  
                                public void run() {  
                                        String onclick = ele.getAttribute("onclick");  
                                        if ( onclick != null && !onclick.equals("") ) {  
                                                browser.execute(onclick);  
                                        }  
                                }  
                        });  
                }  
                                  
                // If the node is an instance of HTMLInputElement, then could be  
                // a submit button (corresponding to types submit and image) then  
                // we must submit the form only if it has the required attribute  
                // 'action'.  
                if (node instanceof HTMLInputElement) {  
                        HTMLInputElement button = (HTMLInputElement) node;  
                          
                        if ( button.getType().equalsIgnoreCase("submit") ||  
                                        button.getType().equalsIgnoreCase("image") ){  
                                  
                                String formAction = button.getForm().getAction();  
                                if ( formAction != null && !formAction.equals("") ){  
                                        submitForm(button.getForm());  
                                }  
                                  
                        }  
                          
                // If the node is an instance of HTMLAnchorElement we only  
                // need to call 'go' method for the 'href' attribute.  
                } else if (node instanceof HTMLAnchorElement) {  
                          
                        HTMLAnchorElement link = (HTMLAnchorElement) node;  
                          
                        if (link.getHref() != null && !link.getHref().equals("")) {  
                                go(link.getHref());  
                        }  
                  
                // If the node is not an instance of HTMLElement class, then we  
                // cannot click on it.  
                } else if ( !(node instanceof HTMLElement) ) {  
                        throw new SimpleBrowserException(  
                                        "Click only works with HTMLElements with onclick "  
                                        + " attribute or links (HTMLAnchorElement) or buttons (HTMLButtonElement)");  
                }  
                  
        }  
          
        private boolean waitLoad(long millis) {  
                try {  
                        // Uses the latch, created by 'go' method to wait for  
                        // the finish of the page loading (it will occurs when  
                        // our 'progressListener' receives a event for its method   
                        // 'completed'), or for a given timeout in case that the  
                        // loading doesn't finish in a reasonable time.  
                        boolean timeout;  
                        timeout = !latch.await(millis,TimeUnit.MILLISECONDS);  
                        if (timeout) {  
                                // If the timeout expired, then we will stop  
                                // page loading.  
                                display.syncExec(new Runnable() {  
                                        public void run() {  
                                                browser.stop();  
                                        }  
                                });  
                                // Waits for the loading is stopped  
                                latch.await(millis,TimeUnit.MILLISECONDS);  
                        }  
                        return timeout;  
                } catch (InterruptedException e) {  
                        throw new Error(e);  
                }  
        }  
          
        private List<Node> xPathNodes(String xpath, nsIDOMNode context) {  
                  
                // Obtain the Mozilla DOM HTML document  
                  
                HTMLDocumentImpl documentImpl = (HTMLDocumentImpl) getW3CDocument();  
                  
                nsIDOMHTMLDocument document =  documentImpl.getInstance();  
                  
                // Creates a name space resolver for the document  
                nsIDOMXPathNSResolver res = xpathEval.createNSResolver(document);  
                  
                List<Node> resultNodes = null;  
                  
                // Evaluates given XPath in a given context, using the resolver created  
                // for the current document as an ordered iterator  
                nsISupports obj = xpathEval.evaluate(xpath, context, res,   
                                nsIDOMXPathResult.ORDERED_NODE_ITERATOR_TYPE, null);  
                // Obtain the interface corresponding to the XPath XPCOM results object  
                nsIDOMXPathResult result = (nsIDOMXPathResult) obj.queryInterface(  
                                nsIDOMXPathResult.NS_IDOMXPATHRESULT_IID);  
                  
                try {  
                        // Extract result nodes for the XPath and add them  
                        // to a standard List.   
                        resultNodes = getNodes(result);  
                } catch(org.mozilla.xpcom.XPCOMException e){  
                        throw e;  
                }                       
                                  
                return resultNodes;  
        }  
          
        private <T> List<T> getNodes(nsIDOMXPathResult result) {  
                List<T> nodes = new ArrayList<T>();  
                  
                nsIDOMNode node;  
                while((node = result.iterateNext()) != null){  
                        // Use the functionality provided by the mozdom4java  
                        // (in our case, patched) library to obtain the corresponding  
                        // W3C implementation of a node.  
                        nodes.add((T)NodeFactory.getNodeInstance(node));  
                }  
                  
                return nodes;  
        }  
          
        private void submitForm(final HTMLFormElement form) throws SimpleBrowserException {  
                // Uses the latch to wait for response page loading when the form  
                // is submitted.  
                latch = new CountDownLatch(1);  
                  
                // Submits the form.  
                display.syncExec(new Runnable() {  
                        public void run() {  
                                form.submit();  
                        }  
                });  
                // Waits for the server response, that is, until the response   
                // page finish loading.  
                boolean timeout = waitLoad(defaultTimeout);  
                if (timeout) {  
                        throw new SimpleBrowserException("Timeout waiting page loading.");  
                }  
                  
        }  
          
        public static void main(String[] args) {  
                String xulrunnerPath = null;  
                if ( args.length > 0 ) {  
                        xulrunnerPath = args[0];  
                }  
                  
                // Instantiate our simple web browser  
                final SimpleBrowserWithClick simpleBrowser = new SimpleBrowserWithClick(xulrunnerPath);  
          
                try{  
                          
                        // Load a web page  
                        simpleBrowser.go("http://www.my400800.cn

");  
                          
                        Thread.sleep(3000);  
                          
                        // Get the W3C DOM anchor element containing the text 'Noticias'  
                        HTMLAnchorElement a =   
                                                        simpleBrowser.xpathNodes("//a[contains(text(),'Noticias')]",  
                                                HTMLAnchorElement.class).get(0);  
                        // Click on the anchor previously obtained  
                        simpleBrowser.click(a);  
                          
                        Thread.sleep(2000);  
                          
                        // Get the input field to write search terms  
                        simpleBrowser.display.syncExec(new Runnable() {  
                            public void run(){  
                                try{  
                                        Node node = simpleBrowser.xpathNodes("//input[@name='q']").get(0);  
                                        simpleBrowser.enter(node, "nasdaq");  
                                }catch (SimpleBrowserException sbe){  
                                        sbe.printStackTrace();  
                                }  
                                  
                              }  
                            });  
                       // Node node = simpleBrowser.xpathNodes("//input[@name='q']").get(0);  
                          
                        // Enter the text 'nasdaq' in the input field  
                          
                        Thread.sleep(2000);  
                          
                        // Get the input button used to submit the form  
                        HTMLInputElement e =  
                                simpleBrowser.xpathNodes("//input[@value='Buscar en Noticias']",  
                                                HTMLInputElement.class).get(0);  
                          
                        // Click the input buuton and start the search for the term 'nasdaq'  
                        // in news section  
                          
                          
                          
                        simpleBrowser.click(e);   
                          
                        Thread.sleep(3000);  
                          
                        // Load a different page with javascript examples  
                        simpleBrowser.go("http://www.codearchive.com/code/0300/0309-acces009.htm");  
                          
                        // Get a W3C anchor element containing an 'onlick' attribute   
                        a = simpleBrowser.xpathNodes("//a[contains(text(),'4')]",  
                                                HTMLAnchorElement.class).get(0);  
                        // Click the anchor and then the javascript will be executed by  
                        // our browser  
                        simpleBrowser.click(a);  
                          
                        Thread.sleep(3000);  
                          
                } catch (SimpleBrowserException e) {  
                        System.err.println("Problems calling go method.");  
                        e.printStackTrace();  
                } catch (InterruptedException e) {  
                        System.err.println("Problems calling sleep.");  
                        e.printStackTrace();  
                }  
                                                  
                Runtime.getRuntime().halt(0);  
                  
        }  
          
}