在我尝试修复非标准名称之前，视图和 bean 一直在工作，现在我已经断开了两者之间的联系。奇怪的是，“返回”按钮有正确的链接，但内容没有显示，也没有记录。为什么 Detail.getComments() 不执行？
我一直在阅读焊接文档并试图更好地理解@Inject。似乎也存在我不理解的生命周期问题。如果它不是生命周期，那么我什至无法推测为什么 Detail.getComments() 从未在 glassfish 日志中显示：
INFO: MessageBean.getModel..
INFO: SingletonNNTP.returning messages..
INFO: MessageBean.getModel..
INFO: SingletonNNTP.returning messages..
INFO: MessageBean.getModel..
INFO: SingletonNNTP.returning messages..
INFO: Detail..
INFO: Detail.getId..null
INFO: Detail.getId..SETTING DEFAULT ID
INFO: Detail.onLoad..2000
INFO: Detail.getId..2000
INFO: Detail.getId..2000
INFO: Detail.setId..2000
INFO: Detail.getId..2019
INFO: ..Detail.setId 2019
INFO: Detail.back..
INFO: Detail.getId..2019
INFO: ..Detail.back 2,018
INFO: Detail.getId..2019
值 2000 是默认值，仅在 id==null 时才会发生，它永远不会发生这种情况。它应该立即引入该属性。所以，我不确定这是否是范围（我现在才发现 CDI 不支持 @SessionScoped）、生命周期或其他问题。也许我需要在那个变量上使用@Inject？
视图，detail.xhtml：
<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">
<body>
<f:metadata>
<f:viewParam name="id" id="id" value="#{detail.id}" />
</f:metadata>
<ui:composition template="./complexTemplate.xhtml">
<ui:define name="top">
<h:link value="back" outcome="detail" includeViewParams="true">
<f:param name="id" value="#{detail.back}"/>
</h:link>
<ui:define name="content">
<h:outputText value="#{detail.content}" rendered="false"/>
</ui:define>
<ui:define name="bottom">
bottom
</ui:define>
</ui:composition>
</body>
</html>
和支持bean：
package net.bounceme.dur.nntp;
import java.io.Serializable;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.annotation.PostConstruct;
import javax.enterprise.context.ConversationScoped;
import javax.inject.Named;
import javax.mail.Message;
@Named
@ConversationScoped
public class Detail implements Serializable {
private static final long serialVersionUID = 1L;
private static final Logger logger = Logger.getLogger(Detail.class.getName());
private static final Level level = Level.INFO;
private String id = null; //should never get default value in getter
private Message message = null;
private SingletonNNTP nntp = SingletonNNTP.INSTANCE;
private String forward = null; //id + 1
private String back = null; //id - 1
private String content = null; //message.content
public Detail() {
logger.log(level, "Detail..");
}
@PostConstruct
private void onLoad() {
logger.log(level, "Detail.onLoad..{0}", getId());
}
public Message getMessage() {
logger.log(level, "Detail.getMessage..");
return message;
}
public void setMessage(Message message) {
logger.log(level, "Detail.setMessage..");
this.message = message;
}
public String getId() {
logger.log(level, "Detail.getId..{0}", id);
if (id == null) {
logger.log(level, "Detail.getId..SETTING DEFAULT ID");
id = String.valueOf(2000);
}
return id;
}
public void setId(String id) throws Exception {
logger.log(level, "Detail.setId..{0}", getId());
this.id = id;
logger.log(level, "..Detail.setId {0}", getId());
}
public String getForward() {
logger.log(level, "Detail.forward..");
int f = Integer.parseInt(getId());
f = f + 1;
logger.log(level, "..Detail.forward {0}", f);
forward = String.valueOf(f);
return forward;
}
public void setForward(String forward) {
this.forward = forward;
}
public String getBack() {
logger.log(level, "Detail.back..");
int b = Integer.parseInt(getId());
b = b - 1;
logger.log(level, "..Detail.back {0}", b);
back = String.valueOf(b);
return back;
}
public void setBack(String back) {
this.back = back;
}
public String getContent() throws Exception {
logger.log(level, "Detail.getContent..{0}", getId());
message = nntp.getMessage(Integer.parseInt(getId()));
content = message.getContent().toString();
return content;
}
public void setContent(String content) {
this.content = content;
}
}
根据上面的日志，它似乎从未调用过 Detail.getContent()，尽管它是视图的一部分： <h:outputText value="#{detail.content}" rendered="false"/>
奇怪的是，在我更改此类以更好地遵循命名约定之前调用了 Detail.content()。我正在阅读一些Weld和Oracle Java EE 6 文档，但完全不介意被引导到一本精美的手册。我发现描述这一点的文档总是使用@ManagedBeans，但是我不是。正如@Kawu在这个答案中所描述的，似乎有很多陷阱。
在 id 字段中添加 @Inject 会导致部署错误：
init:
deps-module-jar:
deps-ear-jar:
deps-jar:
library-inclusion-in-archive:
library-inclusion-in-manifest:
compile:
compile-jsps:
In-place deployment at /home/thufir/NetBeansProjects/NNTPjsf/build/web
Initializing...
deploy?DEFAULT=/home/thufir/NetBeansProjects/NNTPjsf/build/web&name=NNTPjsf&contextroot=/NNTPjsf&force=true failed on GlassFish Server 3.1.2
Error occurred during deployment: Exception while loading the app : WELD-001408 Unsatisfied dependencies for type [String] with qualifiers [@Default] at injection point [[field] @Inject private net.bounceme.dur.nntp.Detail.id]. Please see server.log for more details.
/home/thufir/NetBeansProjects/NNTPjsf/nbproject/build-impl.xml:749: The module has not been deployed.
See the server log for details.
BUILD FAILED (total time: 9 seconds)
当然，注入 String 不是问题，也许是bug。