1

当我尝试通过 localhost/testVaadin/ 在浏览器中加载 servlet 时出现 vaadin 和 servlet 错误

我想执行这个示例来看看 vaadin 是如何工作的，因为我必须使用活动资源管理器来实现一个 BPMN，它使用 vaadin 作为 UI 框架。

我附上了代码和 web.xml 加上抛出的异常。

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;

我的课

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();

职能

@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

而 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 作为网络服务器（6.0.32）

所以错误是：

rg.apache.catalina.core.StandardWrapperValve 调用 GRAVE：Exception lors de l'allocation pour la servlet Testvaadin Application javax.servlet.ServletException：无法加载应用程序类：com.vaadin.terminal.gwt 上的 com.example.testvaadin.SimpleAddressBook .server.ApplicationServlet.init(ApplicationServlet.java:71) 在 org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1173) 在 org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:809 ) 在 org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) 在 org.apache.catalina.core.StandardHostValve 的 org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:129)。在 org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) 在 org.apache.catalina.core 调用(StandardHostValve.java:127)。StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859) at org .apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) at java.lang.Thread.run （线程.java：662）

4

1 回答 1

1

基本上错误消息是说在初始化期间com.vaadin.terminal.gwt.server.ApplicationServlet尝试加载com.example.testvaadin.SimpleAddressBook并且没有成功。

要解决此问题，请尝试以下操作：

  • 检查应用程序部署是否成功以及 class:SimpleAddressBook是否真的在您的 servlet 容器中的正确位置
  • 检查vaadin-xx.yy.zz.jarWEB-INF/lib 中是否有
  • 清理并重建整个项目
于 2012-12-18T10:22:10.453 回答