javabeans

问题 I'm having a hard time understanding why javabeans are necessary and why they didn't just place the javabean features directly into the object class(root class) in java? My understanding is you turn an object(instance) into a java bean and that way you get all the benefits like serializable and so on for all the objects in the bean. But if that is the case, why even have a separate bean class for this, why not just have built into the root object class? Or am I not understand this? 回答1: You

问题 I'm having trouble generating a basic report (master/subreport) with JavaBeans in Jaspersoft Studio. I created TestMainReport.jrxml and TestSubreport.jrxml . TestMainReport.jrxml contains two static text fields, labeled "A Title" in the title band and "A Summary" in the summary band. TestSubreport.jrxml contains two static text fields, "Subreport Title" in the title and "Subreport Summary" in the summary band. I've assigned JavaBeans Data Adapters to them, which are not used (although the

问题 In a scala REPL the following code import scala.beans.BeanProperty class EmailAccount { @scala.beans.BeanProperty var accountName: String = null override def toString: String = { return s"acct ($accountName)" } } classOf[EmailAccount].getDeclaredConstructor() results in res0: java.lang.reflect.Constructor[EmailAccount] = public EmailAccount() however in spark's REPL I get java.lang.NoSuchMethodException: EmailAccount.<init>() at java.lang.Class.getConstructor0(Class.java:2810) at java.lang

问题 I want to use JavaBeans Persistence mechanism to save my GUI to local disk. The problem that I faced is to save two frames at one time. Here is my code. import java.awt.*; import java.awt.event.*; import java.beans.*; import java.io.*; import javax.swing.*; public class BeansTest { private static JFileChooser chooser; private JFrame frame; public static void main(String[] args){ chooser = new JFileChooser(); chooser.setCurrentDirectory(new File(".")); BeansTest test = new BeansTest(); test

问题 Hi All, I am using hibernate with my J2EE app deployed on JBoss 6.0. My database is Oracle 11i and Derby. For generating primary-key (running serial Id) I use @TableGenerator annotation in one of my Entity (PersonDTO) - like: @Entity @Table(name = "EDIS_PERSON") public class PersonDTO { @Id @TableGenerator(name="TABLE_GEN", table="EDIS_SEQUENCE", pkColumnName="SEQ_NAME", valueColumnName="SEQ_COUNT", pkColumnValue="PERSON_ID", allocationSize = 5) @GeneratedValue(strategy=GenerationType.TABLE,

问题 Is there some kind of bean factory or static class that I can use within a Spring configuration file to create an instance of a Java class and set its properties? Something like this: <bean id="myThingy" class="org.whatever.specialBeanMaker"> <property class="${maven.filtered.property.value}" /> <properties> <property name="a" value="...." /> <property name="b" value="...." /> <property name="c" value="...." /> </properties> </bean> In other words, I need to make a bean from a class I won't

问题 According to Phillip Riand (see: discussion on openNTF) this is not possible... They need to know the design element to find out who signed it. Therefore, it is only available in SSJS. 回答1: There are 2 ways that I know of to use the sessionAsSigner object in Java beans: 1 By resolving the sessionAsSigner object: FacesContext context = FacesContext.getCurrentInstance(); Session sessionAsSigner = context.getApplication().getVariableResolver(). resolveVariable(context, "sessionAsSigner"); 2 By

问题 I'm reading the Effective Java book by Joshua Bloch. In the first chapter, he says to use factories instead of constructors and lists the advantages and disadvantages of this approach. As far as I see disadvantages are not closely related to to object construction. Moreover, Bloch says that Java Bean style of construction has disadvantages as well. Source: http://www.javapractices.com/topic/TopicAction.do?Id=84 OK, so using constructors is not great, Java beans are not great, factories are

问题 I would like to use a bean in session scope, but I receive an error: org.springframework.beans.factory.BeanDefinitionStoreException: Failed to read candidate component class: file [C:\Program Files\Apache Software Foundation\Tomcat 8.0\webapps\testRestService\WEB-INF\classes\test\server\config\AppConfig.class]; nested exception is java.lang.annotation.AnnotationFormatError: Invalid default: public abstract org.springframework.beans.factory.annotation.Autowire org.springframework.config.java

问题 My Xml file: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <bean id="filterBySlic" class="ca.ups.tundra.msg.FilterMessagesBySlic"> <property name="slicList"> <list><value>4196</value><value>1101</value><value>2795</value></list> </property> <property name=