Fórum NullPointerException ao tentar adicionar valores no banco #514455

type Exception report

message

description The server encountered an internal error that prevented it from fulfilling this request.

exception

java.lang.NullPointerException
	br.com.caelum.tarefas.dao.TipoDAO.adiciona(TipoDAO.java:28)
	br.com.caelum.tarefas.action.AdicionaTiposAction.execute(AdicionaTiposAction.java:20)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	java.lang.reflect.Method.invoke(Method.java:483)
	com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:441)
	com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:280)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:243)
	com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:165)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:252)
	org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:179)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:130)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
	com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:165)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:179)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
	org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
	org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:488)
	org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
	org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.43 logs.

public class TipoDAO {
private final Connection connection;
	
	//Construtor
	public TipoDAO() {
		try {
			this.connection = new ConnectionFactory().getConnection();
		} catch (SQLException e) {
			throw new RuntimeException(e);
		}
	}
	
	public void adiciona(Tipo tipo){
		String sql= "insert into tipo (descricao) values (?)";
		PreparedStatement stmt;
		try{
			stmt= connection.prepareStatement(sql);
			stmt.setString(1, tipo.getDescricao());
			stmt.execute();
		}catch(SQLException e){
			throw new RuntimeException(e);
		}
	}
}

public class Tipo {
	private Long id;
	private String descricao;
	
	public Long getId() {
		return id;
	}
	public void setId(Long id) {
		this.id = id;
	}
	
	public String getDescricao() {
		return descricao;
	}
	public void setDescricao(String descricao) {
		this.descricao = descricao;
	}
}

@ParentPackage("default")
public class AdicionaTiposAction{
	private Tipo tipo;
	
	@Action(value="adicionaTipo", results = {
			@Result(name="ok", location="tipo-adicionado.jsp"),
			@Result(name = "input", location = "formulario-tipos.jsp")
			})
	
	public String execute(){
		new TipoDAO().adiciona(tipo);
		return "ok";
	}

	public Tipo getTipo() {
		return tipo;
	}

	public void setTipo(Tipo tipo) {
		this.tipo = tipo;
	}

}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC '-//Apache Software Foundation//DTD Struts Configuration 2.0//EN' 'http://struts.apache.org/dtds/struts-2.0.dtd'>    
<struts>    
<package name="default" extends="struts-default">
<interceptors>
		<interceptor name="autorizador"
			class="br.com.caelum.tarefas.interceptador.AutorizadorInterceptor" />
			<interceptor-stack name="seguranca">
				<interceptor-ref name="autorizador" />
				<interceptor-ref name="defaultStack" />
			</interceptor-stack>
	</interceptors>
	
	<global-results>
		<result name="naoLogado">/WEB-INF/content/formulario-login.jsp</result>
	</global-results>
	<action name="tarefaForm" >
		<result>/WEB-INF/content/formulario-tarefas.jsp</result>
	</action>
	
	<action name="tipoForm" >
		<result>/WEB-INF/content/formulario-tipos.jsp</result>
	</action>
	
	<action name="sairLista">
		<result>SessionMap sessao = (SessionMap)ActionContext.getContext().get(ActionContext.SESSION);
		sessao.invalidate();</result>
	</action>
	
	<action name="loginForm" >
		<result>/WEB-INF/content/formulario-login.jsp</result>
	</action>
</package>
</struts>   

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Adicionar tipo</title>
</head>
<body>
<body>
<h3>Adicinar tipos</h3>
	<s:fielderror fieldName="tipo.descricao"/>
<form action="adicionaTipo" method="post">  
    Descricao:<br/>  
    <textarea name="tipo.descricao" rows="5" cols="100"></textarea><br/>  
    <input type="submit" value="Adicionar">  
</form>  
</body>
</html>