Chapter06 中间件 J2EE JavaBean.ppt

* JavaBean Customization - 3 Customizers More elaborate visual interfaces to edit the properties of a bean in a multiple step process Act like wizards or experts Builder tools register with the customizers for property changes and update bean after each change * JavaBean Deployment - 1 Packaging and Deployment JAR (Java ARchive) files are the primary method of packaging and distributing JavaBeans A JAR file contains: Class files Serialized prototypes of a bean Documentation files Resources * JavaBean Deployment - 2 JAR File Example SRC_DIR=com/questra/beans CLASSFILES= \ $(SRC_DIR)\Terminal.class \ $(SRC_DIR)\CursorEvent.class \ $(SRC_DIR)\CursorListener.class \ $(SRC_DIR)\TerminalBeanInfo.class \ $(SRC_DIR)\Terminal$$VetoOpenConnection.class DATAFILES= $(SRC_DIR)\TerminalBeanIconColor16.gif JARFILE= bdk\jars\terminal.jar all: $(JARFILE) # Create a JAR file with a suitable manifest. $(JARFILE): $(CLASSFILES) $(DATAFILES) jar cfm $(JARFILE) manifest.tmp $(SRC_DIR)\*.class $(DATAFILES) Name: com/questra/beans/Terminal.classJava-Bean: True . SUFFIXES: .java .class {$(SRC_DIR)}.java{$(SRC_DIR)}.class : javac $ clean: -del $(SRC_DIR)\*.class -del $(JARFILE) * JavaBean Usage - 1 JavaBean Used in JSP Bean Tag jsp:useBean jsp:setProperty jsp:getProperty * JavaBean Usage - 2 Example – MyFirstBean import java.awt.*; import java.io.Serializable; public class FirstBean extends Canvas implements Serializable { public FirstBean() { setSize(50,30); setBackground(Color.blue); } } * JavaBean Usage - 3 Example – MyFirstBean(Use Beans.instantiate) Frame f; f = new Frame(Testing Beans); try { ClassLoader cl = this.getClass().getClassLoader(); fb =(FirstBean)Beans.instantiate(cl,FirstBean); } catch(Exception e) { e.printStackTrace(); } f.add(fb); * JavaBean Usage - 4 Example – JSP uses JavaBean goodsbean.java package sale; public class goodsbean{??? String Product;??? double Price;?