我有这个托管bean：
package com.DX_57.SR_57;
/** include default packages for Beans */
import java.io.Serializable;
import javax.enterprise.context.SessionScoped;
// or import javax.faces.bean.SessionScoped;
import javax.inject.Named;
/** include package for SHA-256 encryption */
import java.security.NoSuchAlgorithmException;
/** include SQL Packages */
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
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.DX_57.osgi.CL_27.api.CryptoSHA;
import org.glassfish.osgicdi.OSGiService;
import org.DX_57.osgi.SH_27.api.SessionHandle;
@Named("loginController")
@SessionScoped
public class userCheck implements Serializable {
private String user = null;
private String password = null;
private String error_Message = null;
private String error_Database = null;
public userCheck(){
}
/** Call the Oracle JDBC Connection driver */
@Resource(name="jdbc/Oracle")
private DataSource ds;
/** Call OSGI Bundle SH_27 SessionHandle Library */
/** Use transient in order to disable serialization when calling OSGI Bundle */
@Inject @OSGiService(dynamic=true) transient SessionHandle SH;
public String OSGISHCheckUserDB(String CheckUser) throws SQLException{
return SH.CheckUserDB(CheckUser);
}
public String OSGISHSessionRegister(String User) throws SQLException{
return SH.SessionRegister(User);
}
/** Call OSGI Bundle CL_27 Crypto Library */
/** Use transient in order to disable serialization when calling OSGI Bundle */
@Inject @OSGiService(dynamic=true) transient CryptoSHA CL;
public String OSGICLShaEncryptHash(String CString) throws NoSuchAlgorithmException{
return CL.ShaEncryptHash(CString);
}
/** get the content of the variables from the JSF Login page */
public void setUser(String newValue) {
user = newValue;
}
public String getUser(){
return user;
}
public void setPassword(String newValue) {
password = newValue;
}
public String getPassword(){
return password;
}
public String geterror_Database(){
return error_Database;
}
public String geterror_Message(){
return error_Message;
}
/** get user session id */
FacesContext fCtx = FacesContext.getCurrentInstance();
HttpSession session = (HttpSession) fCtx.getExternalContext().getSession(false);
String sessionId = session.getId();
/** get user IP address */
FacesContext context = FacesContext.getCurrentInstance();
HttpServletRequest request = (HttpServletRequest)context.getExternalContext().getRequest();
String remoteHost = request.getRemoteAddr();
/** compare the user and the password */
public String userCompare() throws NoSuchAlgorithmException, SQLException {
String hash_passwd = null;
String passwdQuery = null;
/** check the password into Oracle using the username */
passwdQuery = OSGISHCheckUserDB(user);
/** convert the plain password in SHA-256 hash */
// hash_passwd = string_hash(password);
/** compare the encrypted passwords */
if (password.equals(passwdQuery)){
/** insert into users session table the time when the user login */
// SessionRegister(user);
/* success */
return "0";
} else {
/* failer */
return "1";
}
}
}
我可以使用Netbeans成功编译它。当我在Glassfish上部署它并打开它时，出现以下错误堆栈：
[#|2012-02-04T18:29:36.554+0200|INFO|glassfish3.1.1|org.glassfish.osgijavaeebase|_ThreadID=64;_ThreadName=Thread-2;|deployed bundle com.DX_57.SR_57 [296] at file:/tmp/osgiapp4499752333201324876/|#]
[#|2012-02-04T18:29:48.047+0200|SEVERE|glassfish3.1.1|javax.enterprise.resource.webcontainer.jsf.application|_ThreadID=143;_ThreadName=Thread-2;|Error Rendering View[/home.xhtml]
com.sun.faces.mgbean.ManagedBeanCreationException: Cant instantiate class: com.DX_57.SR_57.userCheck.
at com.sun.faces.mgbean.BeanBuilder.newBeanInstance(BeanBuilder.java:193)
at com.sun.faces.mgbean.BeanBuilder.build(BeanBuilder.java:102)
at com.sun.faces.mgbean.BeanManager.createAndPush(BeanManager.java:409)
at com.sun.faces.mgbean.BeanManager.create(BeanManager.java:269)
at com.sun.faces.el.ManagedBeanELResolver.resolveBean(ManagedBeanELResolver.java:244)
at com.sun.faces.el.ManagedBeanELResolver.getValue(ManagedBeanELResolver.java:116)
at com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:176)
at com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:203)
at com.sun.el.parser.AstIdentifier.getValue(AstIdentifier.java:99)
at com.sun.el.parser.AstValue.getValue(AstValue.java:158)
at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:219)
at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:109)
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
at javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:182)
at javax.faces.component.UIOutput.getValue(UIOutput.java:169)
at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getValue(HtmlBasicInputRenderer.java:205)
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getCurrentValue(HtmlBasicRenderer.java:355)
at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeEnd(HtmlBasicRenderer.java:164)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:875)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1763)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:168)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:845)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1756)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1759)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:401)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:131)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:121)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:139)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:594)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1539)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:98)
at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:91)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:162)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:330)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:174)
at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:828)
at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:725)
at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1019)
at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:225)
at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.NullPointerException
at com.DX_57.SR_57.userCheck.<init>(userCheck.java:103)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
at java.lang.Class.newInstance0(Class.java:372)
at java.lang.Class.newInstance(Class.java:325)
at com.sun.faces.mgbean.BeanBuilder.newBeanInstance(BeanBuilder.java:188)
... 54 more
|#]
问题出在以下几行：
/** get user session id */
FacesContext fCtx = FacesContext.getCurrentInstance();
HttpSession session = (HttpSession) fCtx.getExternalContext().getSession(false);
String sessionId = session.getId();
您能给我一些建议如何修复它们吗？
最佳答案
罪魁祸首在这里：
...getExternalContext().getSession(false);
阅读javadoc布尔参数的作用。
如果
create参数是true，请创建（如有必要）并返回与当前请求关联的会话实例。如果create参数为false，则返回与当前请求关联的任何现有会话实例，如果没有此类会话，则返回null。