Maven 错误：包javax.servlet不存在

我正试图使用jsf 2在我的web应用程序中实现登录过滤器，遵循以下指南：

在我编译了我的过滤器并在“web inf/classes”中添加了.class之后（正如指南所说），过滤器工作了，但我把错误的url重定向到登录页面，所以我从文件夹（web inf/classes）中删除了filter.class，并尝试再次编译该项目，但失败了，从那以后我得到了“package javax.servlet不存在”

这很奇怪，因为在它工作之前，我在pom.xml中有javax.servlet。。我试图清理这个项目，但什么也没有

这是我的筛选器类：

package Bean;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Created with IntelliJ IDEA.
 * User: rodrigo
 * Date: 28-04-13
 * Time: 06:54 AM
 * To change this template use File | Settings | File Templates.
 */
@WebFilter("/Contenido/*")
public class filtro implements Filter {

    @Override
    public void init(FilterConfig config) throws ServletException {
        // If you have any <init-param> in web.xml, then you could get them
        // here by config.getInitParameter("name") and assign it as field.
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws ServletException, IOException {
        HttpServletRequest req = (HttpServletRequest) request;
        LoginBean user = (LoginBean) req.getSession().getAttribute("user");

        if (user != null && user.isLoggedIn()) {
            // User is logged in, so just continue request.
            chain.doFilter(request, response);
        } else {
            // User is not logged in, so redirect to index.
            HttpServletResponse res = (HttpServletResponse) response;
            res.sendRedirect(req.getContextPath() + "/Contenido/Login.xhtml");
        }
    }

    @Override
    public void destroy() {
        // If you have assigned any expensive resources as field of
        // this Filter class, then you could clean/close them here.
    }
}

my 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/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>Frutemu</groupId>
    <artifactId>Frutemu</artifactId>
    <packaging>war</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>Frutemu Maven Webapp</name>
    <url>http://maven.apache.org</url>
    <repositories>
        <repository>
            <id>prime-repo</id>
            <name>Prime Repo</name>
            <url>http://repository.primefaces.org</url>
        </repository>
    </repositories>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>javax.ejb</groupId>
            <artifactId>ejb-api</artifactId>
            <version>3.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.primefaces</groupId>
            <artifactId>primefaces</artifactId>
            <version>3.5</version>
        </dependency>
        <dependency>
            <groupId>org.primefaces.themes</groupId>
            <artifactId>all-themes</artifactId>
            <version>1.0.9</version>
        </dependency>
        <dependency>
            <groupId>javax.faces</groupId>
            <artifactId>jsf-api</artifactId>
            <version>2.0</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>com.sun.faces</groupId>
            <artifactId>jsf-impl</artifactId>
            <version>2.0.2-b10</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <!-- MySQL database driver -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.21</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.web</groupId>
            <artifactId>el-impl</artifactId>
            <version>2.2.1-b04</version>
            <scope>provided</scope>
        </dependency>
        <!-- OpenJPA framework -->
        <dependency>
            <groupId>org.apache.openjpa</groupId>
            <artifactId>openjpa-all</artifactId>
            <version>2.2.0</version>
        </dependency>
        <dependency>
            <groupId>com.microsoft.sqlserver</groupId>
            <artifactId>sqljdbc4</artifactId>
            <version>4.0</version>
        </dependency>
        <dependency>
            <groupId>net.sf.jasperreports</groupId>
            <artifactId>jasperreports</artifactId>
            <version>4.1.2</version>
        </dependency>
    </dependencies>
    <build>
        <finalName>Frutemu</finalName>
        <plugins>
            <!-- Open Jpa -->
            <plugin>
                <groupId>org.apache.openjpa</groupId>
                <artifactId>openjpa-maven-plugin</artifactId>
                <version>2.2.0</version>
                <configuration>
                    <includes>**/model/*.class</includes>
                    <addDefaultConstructor>true</addDefaultConstructor>
                    <enforcePropertyRestrictions>true</enforcePropertyRestrictions>
                </configuration>
                <executions>
                    <execution>
                        <id>enhancer</id>
                        <phase>process-classes</phase>
                        <goals>
                            <goal>enhance</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <!-- Plugin para levantar una instancia de Tomcat 7 liviana, única para este proyecto -->
            <plugin>
                <groupId>org.apache.tomcat.maven</groupId>
                <artifactId>tomcat7-maven-plugin</artifactId>
                <version>2.0</version>
                <configuration>
                    <url>http://127.0.0.1:8080/manager/text</url>
                    <server>TomcatServer</server>
                    <path>/Frutemu</path>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>jasperreports-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile-reports</goal>
                        </goals>
                    </execution>
                </executions>
                <dependencies>
                    <!--note this must be repeated here to pick up correct xml validation -->
                    <dependency>
                        <groupId>net.sf.jasperreports</groupId>
                        <artifactId>jasperreports</artifactId>
                        <version>4.1.2</version>
                    </dependency>
                </dependencies>
            </plugin>
        </plugins>
    </build>
</project>

4.0.0
弗鲁特姆
弗鲁特姆
战争
1.0-快照
Frutemu Maven网络应用程序
http://maven.apache.org
优质回购
优质回购
http://repository.primefaces.org
朱尼特
朱尼特
3.8.1
测试
javax.ejb
EJBAPI
3
假如
org.primefaces
素面
3.5
org.primefaces.themes
所有主题
1.0.9
javax.faces
JSFAPI
2
编译
com.sun.faces
jsf impl
2.0.2-b10
编译
javax.servlet
jstl
1.2
mysql
mysql连接器java
5.1.21
org.glassfish.web
厄尔尼普勒
2.2.1-b04
假如
org.apache.openjpa
openjpa all
2.2.0
com.microsoft.sqlserver
sqljdbc4
4
net.sf.jasperreports
jasperreports
4.1.2
弗鲁特姆
org.apache.openjpa
openjpa maven插件
2.2.0
**/型号/*.class
真的
真的
增强子
进程类
增强
org.apache.tomcat.maven
tomcat7 maven插件
2
http://127.0.0.1:8080/manager/text
TomcatServer
/弗鲁特姆
org.codehaus.mojo
jasperreports maven插件
编写报告
net.sf.jasperreports
jasperreports
4.1.2

pom.xml中缺少javax.servlet依赖项。将以下内容添加到“依赖项”节点：

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.0.1</version>
    <scope>provided</scope>
</dependency>

javax.servlet
javax.servlet-api
3.0.1
假如

我只将此代码放在pom.xml中，并执行了命令maven install

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.0.1</version>
    <scope>provided</scope>
</dependency>

javax.servlet
javax.servlet-api
3.0.1
假如

在我的例子中，将Spring 3.1应用程序迁移到3.2.7，我的解决方案与Matthias的类似，但有点不同——因此我在这里记录它的原因：

在我的POM中，我发现了这种依赖关系，并将其从6.0更改为7.0：

    <dependency>
        <groupId>javax</groupId>
        <artifactId>javaee-web-api</artifactId>
        <version>7.0</version>
        <scope>provided</scope>
    </dependency>

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-dependency-plugin</artifactId>
            <version>2.1</version>
            <executions>
                <execution>
                    ...
                    <configuration>
                        ...
                        <artifactItems>
                            <artifactItem>
                                <groupId>javax</groupId>
                                <artifactId>javaee-endorsed-api</artifactId>
                                <version>7.0</version>
                                <type>jar</type>
                            </artifactItem>
                        </artifactItems>
                    </configuration>
                </execution>
            </executions>
        </plugin>

爪哇
javaeewebapi
7
假如

后来在POM中，我将这个插件从6.0升级到7.0：

    <dependency>
        <groupId>javax</groupId>
        <artifactId>javaee-web-api</artifactId>
        <version>7.0</version>
        <scope>provided</scope>
    </dependency>

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-dependency-plugin</artifactId>
            <version>2.1</version>
            <executions>
                <execution>
                    ...
                    <configuration>
                        ...
                        <artifactItems>
                            <artifactItem>
                                <groupId>javax</groupId>
                                <artifactId>javaee-endorsed-api</artifactId>
                                <version>7.0</version>
                                <type>jar</type>
                            </artifactItem>
                        </artifactItems>
                    </configuration>
                </execution>
            </executions>
        </plugin>

org.apache.maven.plugins
maven依赖插件
2.1
...
...
爪哇
javaee认可的api
7
罐子

由@Matthias Herlitzius提供的答案基本上是正确的。只是为了进一步澄清

servlet api jar最好由服务器来管理

尽管如此，要添加的依赖项可能因服务器/容器而异。例如，在Wildfly中，依赖项是

<dependency>
    <groupId>org.jboss.spec.javax.servlet</groupId>
    <artifactId>jboss-servlet-api_3.1_spec</artifactId>
    <scope>provided</scope>
</dependency>

org.jboss.spec.javax.servlet
jboss-servlet-api_3.1_规范
假如

---

因此，请注意检查容器是如何提供servlet实现的。

可能不存在javaee-api-7.0.jar。 下载这个jar并在你的项目上点击右键

在项目上单击鼠标右键

构建路径

配置生成路径

添加外部罐子

javaee-api-7.0.jar选择

涂抹并完成

---

我还需要导入JavaEEAPI

  <dependency>
     <groupId>javax</groupId>
     <artifactId>javaee-api</artifactId>
     <version>7.0</version>
  </dependency>

---

我在Gradle构建中遇到了类似的问题，并以类似的方式修复了它：

Unable to load class hudson.model.User due to missing dependency javax/servlet/ServletException

固定为：

dependencies {
   implementation('javax.servlet:javax.servlet-api:3.0.1')
}

---

请使用有效的包名，如示例中所示。编写“package com.example；”而不是“package Bean；”。此外，关于Java命名约定，我建议以大写字母（Filtro而不是Filtro）开头类名。你还收到错误消息吗？包名还可以，当我在文件夹“Bean”中创建一个新类时，它是在intellij中自动生成的，