您好我正在尝试使用requestfactory，看看它是否比RPC更好。
每当我尝试运行我的GWT应用程序时，我都会遇到错误 -
[ERROR] [exampledataextractrf] Uncaught exception escaped
com.google.web.bindery.event.shared.UmbrellaException: Exception caught: The call failed on the server due to a ConstraintViolation
at com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext.violation(AbstractRequestContext.java:799)
at com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext$StandardPayloadDialect.processPayload(AbstractRequestContext.java:369)
at com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext$5.onTransportSuccess(AbstractRequestContext.java:1161)
at com.google.web.bindery.requestfactory.gwt.client.DefaultRequestTransport$1.onResponseReceived(DefaultRequestTransport.java:136)
at com.google.gwt.http.client.Request.fireOnResponseReceived(Request.java:259)
at com.google.gwt.http.client.RequestBuilder$1.onReadyStateChange(RequestBuilder.java:412)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:338)
at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:219)
at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:136)
at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:576)
at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:284)
at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91)
at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:347)
at sun.reflect.GeneratedMethodAccessor38.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:293)
at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:547)
at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:364)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.RuntimeException: The call failed on the server due to a ConstraintViolation
at com.google.web.bindery.requestfactory.shared.Receiver.onFailure(Receiver.java:44)
at com.google.web.bindery.requestfactory.shared.Receiver.onViolation(Receiver.java:66)
at com.google.web.bindery.requestfactory.shared.Receiver.onConstraintViolation(Receiver.java:107)
at com.google.web.bindery.requestfactory.shared.impl.AbstractRequest.onViolation(AbstractRequest.java:138)
at com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext.violation(AbstractRequestContext.java:779)
at com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext$StandardPayloadDialect.processPayload(AbstractRequestContext.java:369)
at com.google.web.bindery.requestfactory.shared.impl.AbstractRequestContext$5.onTransportSuccess(AbstractRequestContext.java:1161)
at com.google.web.bindery.requestfactory.gwt.client.DefaultRequestTransport$1.onResponseReceived(DefaultRequestTransport.java:136)
at com.google.gwt.http.client.Request.fireOnResponseReceived(Request.java:259)
at com.google.gwt.http.client.RequestBuilder$1.onReadyStateChange(RequestBuilder.java:412)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:338)
at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:219)
at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:136)
at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:576)
at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:284)
at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91)
at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:347)
at sun.reflect.GeneratedMethodAccessor38.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:293)
at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:547)
at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:364)
at java.lang.Thread.run(Unknown Source)
以下是我尝试使用的onClick代码
final Button buttonMessage = new Button("Click to get the complete list of Employees!!!");
txtName.setWidth("200");
logger.info(txtName.getValue());
buttonMessage.addClickHandler(new ClickHandler() {
public void onClick(ClickEvent event) {
buttonMessage.setEnabled(false);
dataFlexTable.removeAllRows();
dataFlexTable.setText(0, 0, "Employee ID");
dataFlexTable.setText(0, 1, "Employee Name");
dataFlexTable.setText(0, 2, "Department name");
context.findAllEmployees().fire(
new Receiver<List<EmployeeProxy>>(){
@Override
public void onSuccess(List<EmployeeProxy> emp){
logger.info("Inside onSuccess");
addEmployee(emp);
txtName.setEnabled(true);
txtName.setText("");
}
});
}});
我的EmployeeRequestfactory类如下 -
public interface EmployeeRequestFatory extends RequestFactory {
@Service(value=EmployeeDAO.class, locator=DaoLocator.class)
public interface EmployeeRequestContext extends RequestContext{
Request<List<EmployeeProxy>> findAllEmployees();
Request<List<EmployeeProxy>> findEmployee(String name);
}
EmployeeRequestContext context();
}
findAllEmployees（）方法如下 -
public List<Employee> findAllEmployees(){
System.out.println("Inside Main Method");
Connection con = null;
ResultSet rs = null;
Statement stmt=null;
List<Employee> emp=new ArrayList<Employee>();
try{
con = connectionUtil.getConnection();
stmt = con.createStatement();
rs = stmt.executeQuery("select * from Employee");
// logger.log(Level.INFO,rs.toString());
if(rs!=null){
while(rs.next()) {
Employee employee=new Employee();
employee.setId(rs.getLong("EMP_ID"));
employee.setName(rs.getString("EMP_NAME"));
employee.setDepName(rs.getString("DEPT_NAME"));
emp.add(employee);
}
}
} catch (Exception e){
// logger.log(Level.INFO,e.toString());
e.printStackTrace();
}finally{
connectionUtil.closeResources(con, stmt, rs);
}
return emp;
}
任何帮助将不胜感激：）
答案 0 :(得分：1)
在客户端，如果无法验证发送到服务器的对象，则调用Receiver#onConstraintViolation。
这意味着您的代码中还有其他内容可以将对象发送到服务器（基本上是在RequestContext上调用create()或edit()，但它也可以是一个调用你的另一个方法，而不是带有参数的findAllEmployees，并且在服务器上你有一个JSR-303验证器（例如Hibernate Validator）来判断该对象是无效的。这是在您的服务器端findAllEmployees被调用之前完成的。
要对此进行调试，请在ReflectiveServiceLayer#validate（服务器端）内设置断点并查找非空返回值。
在客户端，您可能希望在AbstractRequestContext#takeOwnership内设置断点并查看callstack以确定代码中的哪些内容导致将对象发送到服务器。