在 Java 构建路径上找不到超类“javax.servlet.http.HttpServlet”
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The superclass "javax.servlet.http.HttpServlet" was not found on the Java Build Path
提问by disable1992
I have a project created by Maven integration in Eclipse. All work fine, but in the work space in all JSP files have this:
我有一个由 Maven 集成在 Eclipse 中创建的项目。一切正常，但在所有 JSP 文件的工作空间中都有这样的：
The superclass "javax.servlet.http.HttpServlet" was not found on the Java Build Path
To the first string where place:
到第一个字符串 where 的地方：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
When I create a basic dynamic web project and JSP in - all is fine, no errors.
当我创建一个基本的动态 Web 项目和 JSP 时 - 一切都很好，没有错误。
回答by disable1992
Include servlet-api-3.1.jarin your dependencies.
包含servlet-api-3.1.jar在您的依赖项中。
Maven
<dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.1.0</version> <scope>provided</scope> </dependency>Gradle
configurations { provided } sourceSets { main { compileClasspath += configurations.provided } } dependencies { provided 'javax.servlet:javax.servlet-api:3.1.0' }
马文
<dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.1.0</version> <scope>provided</scope> </dependency>摇篮
configurations { provided } sourceSets { main { compileClasspath += configurations.provided } } dependencies { provided 'javax.servlet:javax.servlet-api:3.1.0' }
回答by Anant Pathak
Select project → Properties→ Project Facets→ Target Runtimes→ VMware Server.
选择 project → Properties→ Project Facets→ Target Runtimes→ VMware Server。
It worked for me.
它对我有用。
回答by DMF
Project → Properties→ Target Runtimes→ Apache Tomcatworked for me. There is no Target Runtimes under Facets (I'm on Eclipse v4.2(Juno)).
项目 →属性→目标运行时→ Apache Tomcat为我工作。Facets 下没有目标运行时（我使用的是Eclipse v4.2(Juno)）。
回答by kas
As this is unanswered, I am guessing something other than Maven dependencies are wrong with the ops build.
由于这是未解决的问题，我猜测 ops 构建除了 Maven 依赖项之外还有其他问题。
While not using Maven, I have the same problem from time to time when re-creating my development environment from svn, and I always forget why and have to figure it out. Unfortunately it seems this is a problem with Eclipse.
虽然不使用 Maven，但从 svn 重新创建我的开发环境时，我不时遇到同样的问题，我总是忘记原因，必须弄清楚。不幸的是，这似乎是 Eclipse 的问题。
I am able to remove all such errors from once working projects by picking just one of the dynamic web projects, or just tomcat dependent projects, and move a dependency in the build order. This seems to force all projects to rebuild properly and all of the errors are then resolved.
我可以通过仅选择一个动态 Web 项目或仅依赖于 tomcat 的项目，并在构建顺序中移动依赖项，从一次工作项目中删除所有此类错误。这似乎迫使所有项目正确重建，然后解决所有错误。
Right click on a web project, select "build Path" -> "Configure Build Path". Go to the tab "Order and Export", then pick a library or jar entry and move it up or down. I used the JRE System Library and moved it to the top.
右键单击一个 Web 项目，选择“构建路径”->“配置构建路径”。转到“订购和导出”选项卡，然后选择一个库或 jar 条目并将其向上或向下移动。我使用了 JRE 系统库并将其移至顶部。
Click OK, and all that red goes away!
单击“确定”，所有红色都消失了！
回答by Mahder
If you are not using Maven, just drop the javax.servlet-api.jar in your project lib folder.
如果您不使用 Maven，只需将 javax.servlet-api.jar 放在您的项目 lib 文件夹中。
回答by Ajil Mohan
Add a runtime first and select project properties. Then check the server name from the 'Runtimes' tab as shown in the image.
首先添加运行时并选择项目属性。然后从“运行时”选项卡中检查服务器名称，如图所示。
回答by Burak Durmu?
Project → Properties→ Target Runtimes→ *Apache Tomcat worked for me. There is no Target Runtimes under Facets (I'm on Eclipse v4.4(Luna)).
项目 →属性→目标运行时→ *Apache Tomcat 为我工作。Facets 下没有目标运行时（我使用的是Eclipse v4.4(Luna)）。
回答by A. El Idrissi
Just add these dependencies to your pom.xmlfile:
只需将这些依赖项添加到您的pom.xml文件中：
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.0.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>javax.servlet.jsp-api</artifactId>
<version>2.2.1</version>
<scope>provided</scope>
</dependency>
回答by adarsh hegde
Adding the Tomcat server in the server runtime will do the job:
在服务器运行时添加 Tomcat 服务器将完成这项工作：
Project properties → Java Build Path→ Add Library→ Select "Server Runtime"from the list → Next→ Select "Apache Tomcat" → Finish.
项目属性→ Java 构建路径→添加库→从列表中选择“服务器运行时”→下一步→选择“Apache Tomcat”→完成。
回答by shashank
In case of JBoss...right click on project → Build Java path→ add external JAR files.
对于 JBoss...右键单击项目 →构建 Java 路径→ 添加外部 JAR 文件。
Then browse to jboss-folder → Common→ lib→ servlet-api.jar
然后浏览到 jboss-folder → Common→ lib→ servlet-api.jar
. . Click OK, refresh the project, and run it...
. . 单击OK，刷新项目，然后运行它...
