Java中的公共字段 [英] Public field in Java
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问题描述
我有这个Managed bean：
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.sql.DataSource;
import javax.annotation.Resource;
import javax.faces.context.FacesContext;
import javax.inject.Inject;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
//或导入javax.faces.bean.ManagedBean;
import org.glassfish.osgicdi.OSGiService;
@Named（ApplicationController）
@SessionScoped
public class Tab1Page实现Serializable {
public String actionString;
public Tab1Page（）{
}
public static final long serialVersionUID = 254415216070877770L;
//常量
public final static String hashKey =tab1PageTab;
public String actApplicationControllerionString =;
@PostConstruct
public void post（）{
Format formatter;
日期日期=新日期（）;
// Time formate 01:12:53 AM
formatter = new SimpleDateFormat（hh：mm：ss a）;
tabName = formatter.format（date）;
System.out.println（Tab1Page\t+ tabName +\ t @ PostConstruct ...）;
}
@PreDestroy
public void destroy（）{
Format formatter;
日期日期=新日期（）;
// Time formate 01:12:53 AM
formatter = new SimpleDateFormat（hh：mm：ss a）;
tabName = formatter.format（date）;
System.out.println（Tab1Page\t+ tabName +\t @ PreDestroy ...）;
}
字符串tabName;
public String getTabName（）{
return this.getClass（）。getName（）。substring（this.getClass（）。getName（）。lastIndexOf（。））+ \ t+ tabName;
}
public void setTabName（String tabName）{
this.tabName = tabName;
}
public String getActionString（）{
String actionString = null;
return actionString;
}
public void setActionString（String actionString）{
this.actionString = actionString;
}
}
当我尝试在Glassfish上部署它时， error：
[＃| 2012-04-16T21：42：51.689 + 0300 | INFO | glassfish3.1.2 | org.glassfish .osgiweb | _ThreadID = 63; _ThreadName = Thread-2; |根据上下文路径移除软件包416 /HM_57-1.0-SNAPSHOT |＃]
[＃| 2012-04-16T21：42：51.690+ 0300 |警告| glassfish3.1.2 | org.glassfish.osgijavaeebase | _ThreadID = 63; _ThreadName =线程2; |无法部署捆绑包com.DX_57.History-Module-57 [416]
org.glassfish.osgijavaeebase .DeploymentException：由于以下原因com.DX_57.History-Module-57 [416]部署失败：部署bundle com.DX_57.History-Module-57 [416]时失败：java.lang.RuntimeException：部署bundle失败[com.DX_57.History-Module-57 [416]]，根本原因：在org.glassfish.osgijavaeebase.AbstractOSGiDeployer.deploy上加载应用程序
时出现异常（AbstractOSGiDeployer.java:125）$ or $ b org .glassfish.osgijavaeebase.OSGiContainer.deploy（OSG org.glassfish.osgijavaeebase.JavaEEExtender.deploy（JavaEEExtender.java:107）
at org.glassfish.osgijavaeebase.JavaEEExtender.access $ 200（JavaEEExtender.java:61）
at org.glassfish.osgijavaeebase.JavaEEExtender $ HybridBundleTrackerCustomizer $ 1.call（JavaEEExtender.java:151）
at org.glassfish.osgijavaeebase.JavaEEExtender $ HybridBundleTrackerCustomizer $ 1.call（JavaEEExtender.java:148）
在java.util.concurrent.FutureTask $ Sync.innerRun（FutureTask.java:334）
在java.util.concurrent.FutureTask.run（FutureTask.java:166）
在java.util。 （ThreadPoolExecutor.java:603）$ b $在java.lang.Thread.run（线程。 java：722）
导致：java.lang.RuntimeException：未能部署bundle [com.DX_57.History-Module-57 [416]]，根本原因：在org中加载应用程序
时出现异常.glassfish.osgij avaeebase.OSGiDeploymentRequest.deploy（OSGiDeploymentRequest.java:196）
at org.glassfish.osgijavaeebase.OSGiDeploymentRequest.execute（OSGiDeploymentRequest.java:118）
at org.glassfish.osgijavaeebase.AbstractOSGiDeployer.deploy（AbstractOSGiDeployer。 java：121）
... 10 more
由org.glassfish.deployment.common.DeploymentException引发：WELD-000075普通范围的托管bean实现类有一个公共字段：public @ Named @SessionScoped class com.DX_57.HM_57.Tab1Page
at org.glassfish.weld.WeldDeployer.event（WeldDeployer.java:181）
at org.glassfish.kernel.event.EventsImpl.send（EventsImpl.java:128 ）
at org.glassfish.internal.data.ApplicationInfo.load（ApplicationInfo.java:277）
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy（ApplicationLifecycle.java:460）
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy（ApplicationLifecycle.java:240）
at org.glassfish.osgijavaeebase.OSGiDeploymentReque st.deploy（OSGiDeploymentRequest.java:183）
... 12 more
原因：org.jboss.weld.exceptions.DefinitionException：WELD-000075正常范围的托管bean实现类有一个公共字段： public @ Named @SessionScoped class com.DX_57.HM_57.Tab1Page
at org.jboss.weld.bean.ManagedBean.checkBeanImplementation（ManagedBean.java:438）
at org.jboss.weld.bean.AbstractClassBean .initialize（AbstractClassBean.java:191）
at org.jboss.weld.bean.ManagedBean.initialize（ManagedBean.java:322）
at org.jboss.weld.bootstrap.AbstractBeanDeployer.deploy（AbstractBeanDeployer .java：115）
at org.jboss.weld.bootstrap.BeanDeployment.deployBeans（BeanDeployment.java:204）
at org.jboss.weld.bootstrap.WeldBootstrap.deployBeans（WeldBootstrap.java:344 ）
at org.glassfish.weld.WeldDeployer.event（WeldDeployer.java:179）
... 17 more
|＃]
我不明白这个错误的含义。我修改了所有的方法是公开的，但我仍然得到这个错误。如何改正代码？
祝愿
解决方案
问题是字段（ public String actionString; ）而不是方法。 $ b
From docs ：
如果托管bean具有公共字段，则它必须具有@Dependent范围。
如果一个带有public字段的托管bean声明除
@Dependent之外的任何作用域，那么容器会自动检测到该问题并将
视为定义错误。
I have this Managed bean:
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.sql.DataSource;
import javax.annotation.Resource;
import javax.faces.context.FacesContext;
import javax.inject.Inject;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
// or import javax.faces.bean.ManagedBean;
import org.glassfish.osgicdi.OSGiService;
@Named("ApplicationController")
@SessionScoped
public class Tab1Page implements Serializable {
public String actionString;
public Tab1Page() {
}
public static final long serialVersionUID = 254415216070877770L;
// Constants
public final static String hashKey = "tab1PageTab";
public String actApplicationControllerionString = "";
@PostConstruct
public void post() {
Format formatter;
Date date = new Date();
// Time formate 01:12:53 AM
formatter = new SimpleDateFormat("hh:mm:ss a");
tabName = formatter.format(date);
System.out.println("Tab1Page\t" + tabName + "\t@PostConstruct...");
}
@PreDestroy
public void destroy() {
Format formatter;
Date date = new Date();
// Time formate 01:12:53 AM
formatter = new SimpleDateFormat("hh:mm:ss a");
tabName = formatter.format(date);
System.out.println("Tab1Page\t" + tabName + "\t@PreDestroy...");
}
String tabName;
public String getTabName() {
return this.getClass().getName().substring(this.getClass().getName().lastIndexOf(".")) + "\t" + tabName;
}
public void setTabName(String tabName) {
this.tabName = tabName;
}
public String getActionString() {
String actionString = null;
return actionString;
}
public void setActionString(String actionString) {
this.actionString = actionString;
}
}
When I try to deploy it on Glassfish I get this error:
[#|2012-04-16T21:42:51.689+0300|INFO|glassfish3.1.2|org.glassfish.osgiweb|_ThreadID=63;_ThreadName=Thread-2;|Removed bundle 416 against context path /HM_57-1.0-SNAPSHOT |#]
[#|2012-04-16T21:42:51.690+0300|WARNING|glassfish3.1.2|org.glassfish.osgijavaeebase|_ThreadID=63;_ThreadName=Thread-2;|Failed to deploy bundle com.DX_57.History-Module-57 [416]
org.glassfish.osgijavaeebase.DeploymentException: Deployment of com.DX_57.History-Module-57 [416] failed because of following reason: Failed while deploying bundle com.DX_57.History-Module-57 [416] : java.lang.RuntimeException: Failed to deploy bundle [ com.DX_57.History-Module-57 [416] ], root cause: Exception while loading the app
at org.glassfish.osgijavaeebase.AbstractOSGiDeployer.deploy(AbstractOSGiDeployer.java:125)
at org.glassfish.osgijavaeebase.OSGiContainer.deploy(OSGiContainer.java:154)
at org.glassfish.osgijavaeebase.JavaEEExtender.deploy(JavaEEExtender.java:107)
at org.glassfish.osgijavaeebase.JavaEEExtender.access$200(JavaEEExtender.java:61)
at org.glassfish.osgijavaeebase.JavaEEExtender$HybridBundleTrackerCustomizer$1.call(JavaEEExtender.java:151)
at org.glassfish.osgijavaeebase.JavaEEExtender$HybridBundleTrackerCustomizer$1.call(JavaEEExtender.java:148)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.RuntimeException: Failed to deploy bundle [ com.DX_57.History-Module-57 [416] ], root cause: Exception while loading the app
at org.glassfish.osgijavaeebase.OSGiDeploymentRequest.deploy(OSGiDeploymentRequest.java:196)
at org.glassfish.osgijavaeebase.OSGiDeploymentRequest.execute(OSGiDeploymentRequest.java:118)
at org.glassfish.osgijavaeebase.AbstractOSGiDeployer.deploy(AbstractOSGiDeployer.java:121)
... 10 more
Caused by: org.glassfish.deployment.common.DeploymentException: WELD-000075 Normal scoped managed bean implementation class has a public field: public@Named @SessionScoped class com.DX_57.HM_57.Tab1Page
at org.glassfish.weld.WeldDeployer.event(WeldDeployer.java:181)
at org.glassfish.kernel.event.EventsImpl.send(EventsImpl.java:128)
at org.glassfish.internal.data.ApplicationInfo.load(ApplicationInfo.java:277)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:460)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:240)
at org.glassfish.osgijavaeebase.OSGiDeploymentRequest.deploy(OSGiDeploymentRequest.java:183)
... 12 more
Caused by: org.jboss.weld.exceptions.DefinitionException: WELD-000075 Normal scoped managed bean implementation class has a public field: public@Named @SessionScoped class com.DX_57.HM_57.Tab1Page
at org.jboss.weld.bean.ManagedBean.checkBeanImplementation(ManagedBean.java:438)
at org.jboss.weld.bean.AbstractClassBean.initialize(AbstractClassBean.java:191)
at org.jboss.weld.bean.ManagedBean.initialize(ManagedBean.java:322)
at org.jboss.weld.bootstrap.AbstractBeanDeployer.deploy(AbstractBeanDeployer.java:115)
at org.jboss.weld.bootstrap.BeanDeployment.deployBeans(BeanDeployment.java:204)
at org.jboss.weld.bootstrap.WeldBootstrap.deployBeans(WeldBootstrap.java:344)
at org.glassfish.weld.WeldDeployer.event(WeldDeployer.java:179)
... 17 more
|#]
I don't understand what this error means. I modified all methods to be public but still I get this error. How I can correct the code?
Best wishes
解决方案
The problem is the field (public String actionString;) not the methods.
From docs:
If a managed bean has a public field, it must have scope @Dependent. If a managed bean with a public field declares any scope other than @Dependent, the container automatically detects the problem and treats it as a definition error.
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