当我尝试通过localhost / testVaadin /
在浏览器中加载servlet时，我有一个vaadin和servlet错误我想执行此示例以了解vaadin的工作原理，因为我必须使用活动资源管理器实现BPMN，它使用vaadin作为UI框架。
我附加了代码，web.xml和抛出的异常。
package com.example.testvaadin;
import com.vaadin.Application;
import com.vaadin.data.Property;
import com.vaadin.data.Property.ValueChangeEvent;
import com.vaadin.data.util.IndexedContainer;
import com.vaadin.ui.Button;
import com.vaadin.ui.Button.ClickEvent;
import com.vaadin.ui.Form;
import com.vaadin.ui.HorizontalLayout;
import com.vaadin.ui.HorizontalSplitPanel;
import com.vaadin.ui.Table;
import com.vaadin.ui.TextField;
import com.vaadin.ui.VerticalLayout;
import com.vaadin.ui.Window;
我的班级
public class SimpleAddressBook extends Application {
变量
private static String[] fields = { "First Name", "Last Name", "Company",
"Mobile Phone", "Work Phone", "Home Phone", "Work Email",
"Home Email", "Street", "Zip", "City", "State", "Country" };
private static String[] visibleCols = new String[] { "Last Name",
"First Name", "Company" };
private Table contactList = new Table();
private Form contactEditor = new Form();
private HorizontalLayout bottomLeftCorner = new HorizontalLayout();
private Button contactRemovalButton;
private IndexedContainer addressBookData = createDummyData();
功能
@Override
public void init() {
initLayout();
initContactAddRemoveButtons();
initAddressList();
initFilteringControls();
}
private void initLayout() {
HorizontalSplitPanel splitPanel = new HorizontalSplitPanel();
setMainWindow(new Window("Address Book", splitPanel));
VerticalLayout left = new VerticalLayout();
left.setSizeFull();
left.addComponent(contactList);
contactList.setSizeFull();
left.setExpandRatio(contactList, 1);
splitPanel.addComponent(left);
splitPanel.addComponent(contactEditor);
contactEditor.setCaption("Contact details editor");
contactEditor.setSizeFull();
contactEditor.getLayout().setMargin(true);
contactEditor.setImmediate(true);
bottomLeftCorner.setWidth("100%");
left.addComponent(bottomLeftCorner);
}
private void initContactAddRemoveButtons() {
// New item button
bottomLeftCorner.addComponent(new Button("+",
new Button.ClickListener() {
public void buttonClick(ClickEvent event) {
// Add new contact "John Doe" as the first item
Object id = ((IndexedContainer) contactList
.getContainerDataSource()).addItemAt(0);
contactList.getItem(id).getItemProperty("First Name")
.setValue("John");
contactList.getItem(id).getItemProperty("Last Name")
.setValue("Doe");
// Select the newly added item and scroll to the item
contactList.setValue(id);
contactList.setCurrentPageFirstItemId(id);
}
}));
// Remove item button
contactRemovalButton = new Button("-", new Button.ClickListener() {
public void buttonClick(ClickEvent event) {
contactList.removeItem(contactList.getValue());
contactList.select(null);
}
});
contactRemovalButton.setVisible(false);
bottomLeftCorner.addComponent(contactRemovalButton);
}
private void initAddressList() {
contactList.setContainerDataSource(addressBookData);
contactList.setVisibleColumns(visibleCols);
contactList.setSelectable(true);
contactList.setImmediate(true);
contactList.addListener(new Property.ValueChangeListener() {
public void valueChange(ValueChangeEvent event) {
Object id = contactList.getValue();
contactEditor.setItemDataSource(id == null ? null : contactList
.getItem(id));
contactRemovalButton.setVisible(id != null);
}
});
}
private void initFilteringControls() {
for (final String pn : visibleCols) {
final TextField sf = new TextField();
bottomLeftCorner.addComponent(sf);
sf.setWidth("100%");
sf.setInputPrompt(pn);
sf.setImmediate(true);
bottomLeftCorner.setExpandRatio(sf, 1);
sf.addListener(new Property.ValueChangeListener() {
public void valueChange(ValueChangeEvent event) {
addressBookData.removeContainerFilters(pn);
if (sf.toString().length() > 0 && !pn.equals(sf.toString())) {
addressBookData.addContainerFilter(pn, sf.toString(),
true, false);
}
getMainWindow().showNotification(
"" + addressBookData.size() + " matches found");
}
});
}
}
private static IndexedContainer createDummyData() {
String[] fnames = { "Peter", "Alice", "Joshua", "Mike", "Olivia",
"Nina", "Alex", "Rita", "Dan", "Umberto", "Henrik", "Rene",
"Lisa", "Marge" };
String[] lnames = { "Smith", "Gordon", "Simpson", "Brown", "Clavel",
"Simons", "Verne", "Scott", "Allison", "Gates", "Rowling",
"Barks", "Ross", "Schneider", "Tate" };
IndexedContainer ic = new IndexedContainer();
for (String p : fields) {
ic.addContainerProperty(p, String.class, "");
}
// Create dummy data by randomly combining first and last names
for (int i = 0; i < 1000; i++) {
Object id = ic.addItem();
ic.getContainerProperty(id, "First Name").setValue(
fnames[(int) (fnames.length * Math.random())]);
ic.getContainerProperty(id, "Last Name").setValue(
lnames[(int) (lnames.length * Math.random())]);
}
return ic;
}
}
这是java部分
并且web.xml是
<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.4"
xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<display-name>testVaadin</display-name>
<context-param>
<description>
Vaadin production mode</description>
<param-name>productionMode</param-name>
<param-value>false</param-value>
</context-param>
<servlet>
<servlet-name>Testvaadin Application</servlet-name>
<servlet-class>com.vaadin.terminal.gwt.server.ApplicationServlet</servlet-class>
<init-param>
<description>
Vaadin application class to start</description>
<param-name>application</param-name>
<param-value>com.example.testvaadin.SimpleAddressBook</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>Testvaadin Application</servlet-name>
<url-pattern>/*</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
</web-app>
我使用tomcat作为webserver（6.0.32）
所以错误是：
rg.apache.catalina.core.StandardWrapperValve调用GRAVE：Exception lors de l＆＃39; allocation pour la servlet Testvaadin Application javax.servlet.ServletException：无法加载应用程序类：com.example.testvaadin.SimpleAddressBook at com。 vaadin.terminal.gwt.server.ApplicationServlet.init（ApplicationServlet.java:71）atg.apache.catalina.core.StandardWrapper.loadServlet（StandardWrapper.java:1173）at org.apache.catalina.core.StandardWrapper.allocate（ StandardWrapper.java:809）org.apache.catalina.core.StandardWrapperValve.invoke（StandardWrapperValve.java:129）org.apache.catalina.core.StandardContextValve.invoke（StandardContextValve.java:191）atg.apache.catalina .core.StandardHostValve.invoke（StandardHostValve.java:127）org.apache.catalina.valves.ErrorReportValve.invoke（ErrorReportValve.java:102）at org.apache.catalina.core.StandardEngineValve.invoke（StandardEngineValve.java:109 ）org.ap上的org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:298） ache.coyote.http11.Http11Processor.process（Http11Processor.java:859）org.apache.coyote.http11.Http11Protocol $ Http11ConnectionHandler.process（Http11Protocol.java:588）at org.apache.tomcat.util.net.JIoEndpoint $ java.lang.Thread.run上的Worker.run（JIoEndpoint.java:489）（Thread.java:662）
答案 0 :(得分：1)
基本上，错误消息是com.vaadin.terminal.gwt.server.ApplicationServlet在初始化期间尝试加载com.example.testvaadin.SimpleAddressBook但未成功。
要解决此问题，请尝试以下操作：
SimpleAddressBook确实位于servlet容器中的正确位置vaadin-xx.yy.zz.jar