GWT整合SPRING

1. 我们这里整合spring主要是用到了一个组件gwt-widgets-server  可以在http://jaist.dl.sourceforge.net/sourceforge/gwt-widget/gwt-widgets-server-0.1.2-bin.zip下载。
2. 我们使用gwt的命令(projectCreator applicationCreator )生成gwt的eclipse项目，参见：http://code.google.com/webtoolkit/gettingstarted.html   
3. 导入eclipse中，导入后请看附件1.
4. 分析代码
首先看web.xml

xml version="1.0" encoding="UTF-8"?>
<web-app>

    <servlet>
        <servlet-name>GWTSpring<!---->servlet-name>
        <servlet-class>
            org.springframework.web.servlet.DispatcherServlet
        <!---->servlet-class>
        <load-on-startup>1<!---->load-on-startup>
    <!---->servlet>

    <servlet-mapping>
        <servlet-name>GWTSpring<!---->servlet-name>
        <url-pattern>*.rpc<!---->url-pattern>
    <!---->servlet-mapping>
    <servlet>
        <servlet-name>shell<!---->servlet-name>
        <servlet-class>com.google.gwt.dev.shell.GWTShellServlet<!---->servlet-class>
    <!---->servlet>

    <servlet-mapping>
        <servlet-name>shell<!---->servlet-name>
        <url-pattern>/static/*<!---->url-pattern>
    <!---->servlet-mapping>

<!---->web-app>

可以看到我们增加了段GWTSpring的servlet配置，熟悉spring-web的朋友一眼就可以看出。gwt-widgets-server 正是使用了spring-web的control来做gwt的remoteServiceServlet的。他是使用了cglib或者javassist 来动态使我们的Sevice class继承RemoteServiceServlet。细心的朋友可以看到代码中的粗体部分，本来直接生成的gwt模版是"/*"的url- pattern。但是我这里为什么要在前面加上"/static"部分呢？请让我在后面为你解释。下面看看GWTSpring-servlet.xml的配置。

xml version="1.0" encoding="UTF-8"?>

>

<beans>
    <bean id="urlMapping" class="org.gwtwidgets.server.spring.GWTHandler" depends-on="userServiceTarget">
        <property name="mapping">
            <map>
                <entry key="/userService.rpc" value-ref="userService" />
            <!---->map>
        <!---->property>
        <property name="usingInstrumentation" value="false" />
        <property name="unwrappingGWTExceptions" value="true" />
        <!---->
            You can specify your own class enhancer here
            <property name="classEnhancer">
            <bean class="org.gwtwidgets.server.spring.enhancer.JavassistEnhancer"/>
            <!---->property>
        -->
    <!---->bean>

    <bean id="userServiceTarget" class="com.javaeye.dengyin2000.truck.server.impl.UserServiceImpl">
    <!---->bean>
    <bean id="userService" class="org.springframework.aop.framework.ProxyFactoryBean">
        <property name="target" ref="userServiceTarget" />
        <property name="autodetectInterfaces" value="true" />
        <property name="interceptorNames">
            <list>
                <value>requestSetter<!---->value>
            <!---->list>
        <!---->property>
    <!---->bean>

    <bean id="requestSetter"
        class="org.gwtwidgets.server.spring.RequestInjection">
        <property name="requestSetterName" value="setRequest" />
        <property name="responseSetterName" value="setResponse" />
    <!---->bean>
<!---->beans>

<beans><bean depends-on="userServiceTarget" class="org.gwtwidgets.server.spring.GWTHandler" id="urlMapping"> <property value="false" name="usingInstrumentation"><bean class="org.springframework.aop.framework.ProxyFactoryBean" id="userService">
</bean></property> </bean></beans><beans><bean depends-on="userServiceTarget" class="org.gwtwidgets.server.spring.GWTHandler" id="urlMapping"> <property value="false" name="usingInstrumentation"><bean class="org.springframework.aop.framework.ProxyFactoryBean" id="userService"> <property ref="userServiceTarget" name="target"><bean id="requestSetter"> </bean></property> </bean></property> </bean></beans> <beans><bean depends-on="userServiceTarget" class="org.gwtwidgets.server.spring.GWTHandler" id="urlMapping"> <property value="false" name="usingInstrumentation"><bean class="org.springframework.aop.framework.ProxyFactoryBean" id="userService"> <property ref="userServiceTarget" name="target"><bean id="requestSetter">我们配置了一个“/userService.rpc”的servlet mapping。你应该可以想到这个url应该就是gwt的RemoteServiceServlet的url。我不想多解释配置里面的内容，因为我也是抄的，如果仔细看的话应该可以明白，如果不明白的话可以看看gwt-widgets-server的源码。这段配置里面主要就是初始化了一个gwt的RemoteServiceServlet。他可以是任何的object。不需要显示的继承RemoteServiceServlet，一切都让org.gwtwidgets.server.spring.GWTHandler帮你解决吧。他还帮你在RemoteServiceServlet注入了httpServletRequest 和 httpServletResponse。你不需要使用通过RemoteServiceServlet.getThreadLocalRequest()去取。下面看看UserServiceImpl

java 代码

package com.javaeye.dengyin2000.truck.server.impl;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

import com.javaeye.dengyin2000.truck.client.server.UserService;

public class UserServiceImpl implements UserService {

    private static ThreadLocal<servletrequest> servletRequest = </servletrequest>new ThreadLocal<servletrequest>();  </servletrequest>

    private static ThreadLocal<servletresponse> servletResponse = </servletresponse>new ThreadLocal<servletresponse>();  </servletresponse>

    public void setRequest(ServletRequest request) {
        servletRequest.set(request);
    }

    public void setResponse(ServletResponse request) {
        servletResponse.set(request);
    }

    protected HttpServletRequest getRequest() {
        return (HttpServletRequest) servletRequest.get();
    }

    public boolean checkUser(String userName, String password) {
        if ("denny".equals(userName) && "123456".equals(password)) {
            getRequest().getSession().setAttribute("user", userName);
            return Boolean.TRUE;
        }
        return Boolean.FALSE;
    }

}

这里面有个checkUser方法。在这里我发现了一个问题。gwt-widgets-server中的例子上面setRequest和setResponse方法里面的参数的类型是HttpServletRequest和HttpServletResponse但是这样的话，requst和response不能被注入。清看gwt-widgets-server中的RequestInjection class

java 代码

package org.gwtwidgets.server.spring;

import java.lang.reflect.Method;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;

/**
 * Method interceptor that injects the current {@link HttpServletRequest} and
 * the current {@link HttpServletResponse} via reflection to a target. You must specify
 * the setter names via {@link #setRequestSetterName(String)} and {@link #setResponseSetterName(String)}
 * otherwise they will fail silently. These setters can and must have only a single argument
 * namely {@link ServletRequest} and {@link ServletResponse} respectively.
 *
 * @author George Georgovassilis
 *
 */
public class RequestInjection implements MethodInterceptor {

    protected String requestSetterName;

    protected String responseSetterName;

    private void setRequestOnTarget(HttpServletRequest request, HttpServletResponse response, Object target)
        throws Exception {
    if (requestSetterName != null)
        try {
        Method method = target.getClass().getMethod(requestSetterName,
            new Class[] { ServletRequest.class });
        method.invoke(target, new Object[] { request });
        } catch (NoSuchMethodException e) {
        }
    if (responseSetterName != null)
        try {
        Method method = target.getClass().getMethod(responseSetterName,
            new Class[] { ServletResponse.class });
        method.invoke(target, new Object[] { response });
        } catch (NoSuchMethodException e) {
        }
    }

    public Object invoke(MethodInvocation invocation) throws Throwable {
    Object target = invocation.getThis();
    setRequestOnTarget(GWTSpringController.getRequest(), GWTSpringController.getResponse(), target);
    return invocation.proceed();
    }

    /**
         * Specify the name of the setter method that can be invoked to set the
         * current request and response on the target. If the method does not
         * exist on the target, it is silently discarded.
         *
         * @param setterName
         */
    public void setRequestSetterName(String setterName) {
    this.requestSetterName = setterName;
    }

    /**
         * Specify the name of the setter method that can be invoked to set the
         * current response on the target. If the method does not exist on the
         * target, it is silently discarded.
         *
         * @param setterName
         */
    public void setResponseSetterName(String setterName) {
    this.responseSetterName = setterName;
    }

}

请看上面的粗体部分他这里取的参数类型是ServletRequest和ServletResponse。所以我把UserServiceImpl中的setRequest和setResponse类型改成了ServletRequest和ServletResponse。在getRequest中cast成HttpServletRequest。ok，看看在gwt的client中怎么调用吧。

java 代码

package com.javaeye.dengyin2000.truck.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.core.client.GWT;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.rpc.ServiceDefTarget;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.ClickListener;
import com.google.gwt.user.client.ui.DockPanel;
import com.google.gwt.user.client.ui.FlexTable;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.PasswordTextBox;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.Widget;
import com.javaeye.dengyin2000.truck.client.server.UserService;
import com.javaeye.dengyin2000.truck.client.server.UserServiceAsync;

/**
 * Entry point classes define onModuleLoad().
 */
public class TruckApp implements EntryPoint {
    private TextBox userName;

    private PasswordTextBox password;

    private Button submit;

    private FlexTable loginTable;

    public static final HTML HEAD_TITLE = new HTML(");

    private UserServiceAsync userService;

    /**
     * This is the entry point method.
     */
    public void onModuleLoad() {

        DockPanel panel = new DockPanel();
        panel.setVerticalAlignment(DockPanel.ALIGN_MIDDLE);
        panel.setHorizontalAlignment(DockPanel.ALIGN_CENTER);
        submit = new Button("提交");
        submit.addClickListener(new ClickListener(){

            public void onClick(Widget sender) {
                // TODO check the user for validate
                getUserClientService().checkUser(userName.getText(), password.getText(), new AsyncCallback(){

                    public void onFailure(Throwable caught) {
                        Window.alert("Server error!");
                    }

                    public void onSuccess(Object result) {
                        if (((Boolean)result).booleanValue() == true){
                            Window.alert("Login successfully!");
                        }else{
                            Window.alert("Login failed!");
                        }
                    }

                });
            }

        });

        userName = new TextBox();
        password = new PasswordTextBox();

        loginTable = createLoginTable();

        panel.setWidth("100%");
        panel.setHeight("100%");

        loginTable.setWidget(2, 0, submit);
        panel.add(loginTable, DockPanel.CENTER);
        panel.add(HEAD_TITLE, DockPanel.NORTH);

        RootPanel.get().add(panel);
    }

    private FlexTable createLoginTable() {
        FlexTable table = new FlexTable();
        table.setText(0, 0, "用户名:");
        table.setWidget(0, 1, userName);
        table.setText(1, 0, "密  码:");
        table.setWidget(1, 1, password);
        table.setStyleName("ks-layouts-Label");
        return table;
    }

    private UserServiceAsync getUserClientService(){
        if (userService == null){
            userService = (UserServiceAsync) GWT.create(UserService.class);
            ServiceDefTarget endPoint = (ServiceDefTarget) userService;
            String moduleRelativeURL = "/userService.rpc";
            endPoint.setServiceEntryPoint(moduleRelativeURL);
        }
        return userService;
    }
}

java 代码

package com.javaeye.dengyin2000.truck.client.server;

import com.google.gwt.user.client.rpc.RemoteService;

public interface UserService extends RemoteService {
    boolean checkUser(String userName, String password);
}

java 代码

package com.javaeye.dengyin2000.truck.client.server;

import com.google.gwt.user.client.rpc.AsyncCallback;

public interface UserServiceAsync {
    void checkUser(String userName, String password, AsyncCallback callback);
}

ok。到此配置结束。对了好像还忘了解释为什么要在web.xml中加上/static这段。原因是如果shell的url-pattern是/*的话，就会handler了gwt的RemoteServiceServlet的路径，这样的话remote rpc调用就总是Server error了。这时我们访问地址需要变成http://localhost:8888/static/com.javaeye.dengyin2000.truck.TruckApp/TruckApp.html 这样了。我提交了整个eclipse gwt项目所有代码但是把require lib去掉了。 需要的lib是spring-1.2.8.jar log4j-1.2.13.jar javassist-3.0.jar gwt-widgets-server-0.1.2.jar gwt-servlet.jar commons-logging-1.1.jar cglib-nodep-2.1_3.jar。请自行下载然后放到eclipse项目中的tomcat\webapps\ROOT\WEB-INF\lib\下面。你还需要把项目中引用到gwt lib的路径换成你自己机子上的。

:)

参考：http://g.georgovassilis.googlepages.com/usingthegwthandler
</bean></property> </bean></property> </bean></beans>

评论

11 楼 dengyin2000 2007-03-12  

vicself 写道

我引入你的project,但是在hosted mode 下出现以下错误：

[ERROR] Unable to find 'userService/rpc.gwt.xml' on your classpath; could be a typo, or maybe you forgot to include a classpath entry for source?

那些依赖包都放好，什么原因啊？

谢谢。

路径有没有换成  http://localhost:8888/static/com.javaeye.dengyin2000.truck.TruckApp/TruckApp.html 呢？？

主意web.xml中的shell需要配成 

	<servlet>
		<servlet-name>shell</servlet-name>
		<servlet-class>com.google.gwt.dev.shell.GWTShellServlet</servlet-class>
	</servlet>
	
	<servlet-mapping>
		<servlet-name>shell</servlet-name>
		<url-pattern>/static/*</url-pattern>
	</servlet-mapping>

10 楼 vicself 2007-03-12  

我引入你的project,但是在hosted mode 下出现以下错误：

[ERROR] Unable to find 'userService/rpc.gwt.xml' on your classpath; could be a typo, or maybe you forgot to include a classpath entry for source?

那些依赖包都放好，什么原因啊？

谢谢。

9 楼 dengyin2000 2007-03-09  

还是没有搞定， 可以用了feditor后不能用bbcode了

8 楼 dearwolf 2007-03-09  

bbcode排版我还没学会....但是我重新粘帖以后就没问题了的说，你可以看看我这个帖子：

http://www.iteye.com/topic/58265

7 楼 dengyin2000 2007-03-09  

重新粘贴还是有问题。 在写的时候没有问题， 提交后就乱了。 回家后， 我改成bbcode排版吧。 听说bbcode没有问题。

6 楼 dearwolf 2007-03-09  

xml格式的编辑器有bug，你第一次粘贴进去以后，以后再改文章的时候，基本上都要重新粘贴一边才行

5 楼 dengyin2000 2007-03-08  

报表是server端的事情吧。

4 楼 adablue77 2007-03-08  

可惜还是初级会员不能投票,呵呵
早点看到这篇文章就好了,我是参考GwtPetstore那个项目,我水平太低,分析了好久才模仿成功的.
兄台有没有关于Gwt和报表结合使用相关的文章?

3 楼 dengyin2000 2007-03-08  

dengyin2000 写道

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">

<beans>
<bean id="urlMapping" class="org.gwtwidgets.server.spring.GWTHandler" depends-on="userServiceTarget">
<property name="mapping">
<map>
<entry key="/userService.rpc" value-ref="userService" />
</map>
</property>
<property name="usingInstrumentation" value="false" />
<property name="unwrappingGWTExceptions" value="true" />
<!--
You can specify your own class enhancer here
<property name="classEnhancer">
<bean class="org.gwtwidgets.server.spring.enhancer.JavassistEnhancer"/>
</property>
-->
</bean>

<bean id="userServiceTarget" class="com.javaeye.dengyin2000.truck.server.impl.UserServiceImpl">
</bean>
<bean id="userService" class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="target" ref="userServiceTarget" />
<property name="autodetectInterfaces" value="true" />
<property name="interceptorNames">
<list>
<value>requestSetter</value>
</list>
</property>
</bean>

<bean id="requestSetter"
class="org.gwtwidgets.server.spring.RequestInjection">
<property name="requestSetterName" value="setRequest" />
<property name="responseSetterName" value="setResponse" />
</bean>
</beans>

2 楼 dengyin2000 2007-03-08  

调整格式花了一个小时，基本上每种格式都试过了。 还是不行。请看附件里面的文件吧。java代码的格式没有问题。

1 楼 dengyin2000 2007-03-08  

xml格式不正确，浪费了很多时间呀。本以为java格式是正确的，想用java格式。可是出来更吓人。