Question

我使用MyEclipse创建了一个支持maven的web项目。有一个jsp文件index.jsp所以我想运行该项目。为此我启动了MyEclipse tomcat服务器并在正在运行的服务器上部署了这个项目。

当我执行时，它会给我以下错误

SEVERE: Servlet.service() for servlet jsp threw exception
java.lang.NullPointerException
    at org.apache.jsp.index_jsp._jspInit(index_jsp.java:23)
    at org.apache.jasper.runtime.HttpJspBase.init(HttpJspBase.java:52)
    at org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:159)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:329)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
    at java.lang.Thread.run(Thread.java:619)

这是我第一次创建maven项目时，我也想在项目中使用maven。任何形式的帮助都会很明显。

这是我的pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>nmrk</groupId>
  <artifactId>nmrk</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>
  <name/>
  <description/>
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
  <dependencies>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>bean-validator</artifactId>
      <version>3.0-JBoss-4.0.2</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.annotation</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.ejb</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.enterprise.deploy</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.jms</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.management.j2ee</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.eclipse.persistence</groupId>
      <artifactId>javax.persistence</artifactId>
      <version>2.0.0</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.resource</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.security.auth.message</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.security.jacc</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.servlet</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.servlet.jsp</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.servlet.jsp.jstl</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish</groupId>
      <artifactId>javax.transaction</artifactId>
      <version>3.0.1</version>
    </dependency>
    <dependency>
      <groupId>javax.xml.bind</groupId>
      <artifactId>jaxb-api-osgi</artifactId>
      <version>2.2.1</version>
    </dependency>
    <dependency>
      <groupId>javax.ws.rs</groupId>
      <artifactId>jsr311-api</artifactId>
      <version>1.1.1</version>
    </dependency>
    <dependency>
      <groupId>org.glassfish.web</groupId>
      <artifactId>jstl-impl</artifactId>
      <version>1.2</version>
    </dependency>
    <dependency>
      <groupId>javax.mail</groupId>
      <artifactId>mail</artifactId>
      <version>1.4.3</version>
    </dependency>
    <dependency>
      <groupId>javax.xml</groupId>
      <artifactId>webservices-api-osgi</artifactId>
      <version>2.0.1</version>
    </dependency>
    <dependency>
      <groupId>org.jboss.weld</groupId>
      <artifactId>weld-osgi-bundle</artifactId>
      <version>1.0.1-SP3</version>
    </dependency>
  </dependencies>
  <build>
    <sourceDirectory>${basedir}/src</sourceDirectory>
    <outputDirectory>${basedir}/WebRoot/WEB-INF/classes</outputDirectory>
    <resources>
      <resource>
        <directory>${basedir}/src</directory>
        <excludes>
          <exclude>**/*.java</exclude>
        </excludes>
      </resource>
    </resources>
    <plugins>
      <plugin>
        <artifactId>maven-war-plugin</artifactId>
        <configuration>
          <webappDirectory>${basedir}/WebRoot</webappDirectory>
          <warSourceDirectory>${basedir}/WebRoot</warSourceDirectory>
        </configuration>
      </plugin>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <source>1.6</source>
          <target>1.6</target>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

Answer 1

这件事发生在我身上好几次，我认为我的pom包含了一些已经存在于Web容器中的库[在本例中是MyEclipse Tomcat Server]，因此存在冲突。

应该做什么诀窍是从pom中删除这些依赖项[或将它们标记为“提供”]，我不记得它们，但几乎所有内容都以javax开头。

如何使用maven支持执行Web项目

1 个答案: