Java 尝试在tomcat中显示某些内容时出现错误404

我做了这一切： 但当我打字时：

http://localhost:8080/spring-sample-1.0-SNAPSHOT/hello

显示此错误：

HTTP Status 404 – Not Found
Type Status Report

Message The requested resource [/spring-sample-1.0-SNAPSHOT/hello] is not available

Description The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

@Configuration
@ComponentScan({"app"})
@EnableWebMvc
public class Config extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[0];
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[0];
    }

    @Override
    protected String[] getServletMappings() {
        return new String[0];
    }
}

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class Hello {

    @GetMapping("/hello")
    public String get(){
        return "Bycza zagroda!";
    }
}

<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>pl.bykowski</groupId>
    <artifactId>spring-sample</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
        <maven.compiler.source>15</maven.compiler.source>
        <maven.compiler.target>15</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.1.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.8</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.8</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.2.3</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

21-Dec-2020 16:49:22.227 INFO [http-nio-8000-exec-17] org.apache.catalina.startup.HostConfig.deployWAR Deploying web application archive [C:\Users\Damian\Desktop\JAVA\apache-tomcat-8.5.61\webapps\spring-sample3-1.0-SNAPSHOT.war]
21-Dec-2020 16:49:24.113 INFO [http-nio-8000-exec-17] org.apache.jasper.servlet.TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
21-Dec-2020 16:49:24.138 INFO [http-nio-8000-exec-17] org.apache.catalina.startup.HostConfig.deployWAR Deployment of web application archive [C:\Users\Damian\Desktop\JAVA\apache-tomcat-8.5.61\webapps\spring-sample3-1.0-SNAPSHOT.war] has finished in [1,907] ms

我唯一改变的是：tomcat/bin/setclasspath.bat，我在那里添加了一行：

set JRE_HOME=C:\Program Files\Java\jre1.8.0_271

因为没有它，服务器就无法启动

好的，所以我的应用程序非常简单，我用java 15创建了mvn项目，然后创建了两个类：

配置：

HTTP Status 404 – Not Found
Type Status Report

Message The requested resource [/spring-sample-1.0-SNAPSHOT/hello] is not available

Description The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

@Configuration
@ComponentScan({"app"})
@EnableWebMvc
public class Config extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[0];
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[0];
    }

    @Override
    protected String[] getServletMappings() {
        return new String[0];
    }
}

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class Hello {

    @GetMapping("/hello")
    public String get(){
        return "Bycza zagroda!";
    }
}

<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>pl.bykowski</groupId>
    <artifactId>spring-sample</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
        <maven.compiler.source>15</maven.compiler.source>
        <maven.compiler.target>15</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.1.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.8</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.8</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.2.3</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

21-Dec-2020 16:49:22.227 INFO [http-nio-8000-exec-17] org.apache.catalina.startup.HostConfig.deployWAR Deploying web application archive [C:\Users\Damian\Desktop\JAVA\apache-tomcat-8.5.61\webapps\spring-sample3-1.0-SNAPSHOT.war]
21-Dec-2020 16:49:24.113 INFO [http-nio-8000-exec-17] org.apache.jasper.servlet.TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
21-Dec-2020 16:49:24.138 INFO [http-nio-8000-exec-17] org.apache.catalina.startup.HostConfig.deployWAR Deployment of web application archive [C:\Users\Damian\Desktop\JAVA\apache-tomcat-8.5.61\webapps\spring-sample3-1.0-SNAPSHOT.war] has finished in [1,907] ms

pom.xml:

HTTP Status 404 – Not Found
Type Status Report

Message The requested resource [/spring-sample-1.0-SNAPSHOT/hello] is not available

Description The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

@Configuration
@ComponentScan({"app"})
@EnableWebMvc
public class Config extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[0];
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[0];
    }

    @Override
    protected String[] getServletMappings() {
        return new String[0];
    }
}

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class Hello {

    @GetMapping("/hello")
    public String get(){
        return "Bycza zagroda!";
    }
}

<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>pl.bykowski</groupId>
    <artifactId>spring-sample</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
        <maven.compiler.source>15</maven.compiler.source>
        <maven.compiler.target>15</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.1.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.8</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.8</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.2.3</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

21-Dec-2020 16:49:22.227 INFO [http-nio-8000-exec-17] org.apache.catalina.startup.HostConfig.deployWAR Deploying web application archive [C:\Users\Damian\Desktop\JAVA\apache-tomcat-8.5.61\webapps\spring-sample3-1.0-SNAPSHOT.war]
21-Dec-2020 16:49:24.113 INFO [http-nio-8000-exec-17] org.apache.jasper.servlet.TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
21-Dec-2020 16:49:24.138 INFO [http-nio-8000-exec-17] org.apache.catalina.startup.HostConfig.deployWAR Deployment of web application archive [C:\Users\Damian\Desktop\JAVA\apache-tomcat-8.5.61\webapps\spring-sample3-1.0-SNAPSHOT.war] has finished in [1,907] ms

4.0.0
比可夫斯基
弹簧样品
1.0-快照
战争
15
15
org.springframework
SpringWebMVC
5.1.5.1发布
com.fasterxml.jackson.core
杰克逊核心
2.9.8
com.fasterxml.jackson.core
杰克逊数据绑定
2.9.8
javax.servlet
javax.servlet-api
4.0.1
假如
org.apache.maven.plugins
maven战争插件
3.2.3
假的

然后我将所有内容打包到war文件中，并将其添加到tomcat manager中：要部署的war文件

之后，我在tomcat模块中单击了/spring-sample-1.0-SNAPSHOT

然后在结尾打招呼

---

你知道怎么回事吗/

首先，我建议为操作系统设置JAVA_HOME或JRE_HOME env变量。 有关详细信息： 无论如何，更改tomcat的文件都不是好主意：）

要解决无法访问url的问题，请检查：

对于已安装的tomcat：

• 通常，war文件的名称是上下文名称和url的一部分（spring-sample-1.0-SNAPSHOT），但该名称可以在context.xml中配置（文档：）
• 打开管理器窗口，如视频中所示(http://localhost:8080/manager/html)并找到web应用程序的链接

对于嵌入式tomcat：

• 上下文路径应该类似于pom.xml中的artifactId
@saver
部署时从tomcat记录：

HTTP Status 404 – Not Found
Type Status Report

Message The requested resource [/spring-sample-1.0-SNAPSHOT/hello] is not available

Description The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

@Configuration
@ComponentScan({"app"})
@EnableWebMvc
public class Config extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[0];
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[0];
    }

    @Override
    protected String[] getServletMappings() {
        return new String[0];
    }
}

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class Hello {

    @GetMapping("/hello")
    public String get(){
        return "Bycza zagroda!";
    }
}

<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>pl.bykowski</groupId>
    <artifactId>spring-sample</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
        <maven.compiler.source>15</maven.compiler.source>
        <maven.compiler.target>15</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.1.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.8</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.8</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.2.3</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

21-Dec-2020 16:49:22.227 INFO [http-nio-8000-exec-17] org.apache.catalina.startup.HostConfig.deployWAR Deploying web application archive [C:\Users\Damian\Desktop\JAVA\apache-tomcat-8.5.61\webapps\spring-sample3-1.0-SNAPSHOT.war]
21-Dec-2020 16:49:24.113 INFO [http-nio-8000-exec-17] org.apache.jasper.servlet.TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
21-Dec-2020 16:49:24.138 INFO [http-nio-8000-exec-17] org.apache.catalina.startup.HostConfig.deployWAR Deployment of web application archive [C:\Users\Damian\Desktop\JAVA\apache-tomcat-8.5.61\webapps\spring-sample3-1.0-SNAPSHOT.war] has finished in [1,907] ms

---

那么，我应该使用哪些版本的JRE和JDK呢？
@daniep kajoi您应该为tomcat在java 15上设置路径，或者在1.8版本上更改pom.xml中的maven.compiler.source属性-两个选项之一。 我在你的日志中看到你的路径是“spring-sample3-1.0-SNAPSHOT.war”

21-Dec-2020 16:49:22.227 INFO [http-nio-8000-exec-17] org.apache.catalina.startup.HostConfig.deployWAR Deploying web application archive [C:\Users\Damian\Desktop\JAVA\apache-tomcat-8.5.61\webapps\spring-sample3-1.0-SNAPSHOT.war]
21-Dec-2020 16:49:24.113 INFO [http-nio-8000-exec-17] org.apache.jasper.servlet.TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
21-Dec-2020 16:49:24.138 INFO [http-nio-8000-exec-17] org.apache.catalina.startup.HostConfig.deployWAR Deployment of web application archive [C:\Users\Damian\Desktop\JAVA\apache-tomcat-8.5.61\webapps\spring-sample3-1.0-SNAPSHOT.war] has finished in [1,907] ms

---

尝试打开url:http://localhost:8080/spring-sample3-1.0-SNAPSHOT.war/hello
我发现了问题：在配置类中，您为servlet映射和servlet配置类提供了不正确的值。 请按如下方式更改配置类：

@Configuration
@ComponentScan({"app"})
@EnableWebMvc
public class Config extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[0];
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[] {Config.class};
    }

    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }
}

@配置
@组件扫描（{“应用程序”}）
@EnableWebMvc
公共类配置扩展了AbstractAnnotationConfigDispatcherServletInitializer{
@凌驾
受保护类[]getRootConfigClasses（）{
返回新类[0]；
}
@凌驾
受保护类[]getServletConfigClasses（）{
返回新类[]{Config.Class}；
}
@凌驾
受保护的字符串[]getServletMappings（）{
返回新字符串[]{”/“}；
}
}

在我的情况下，上下文名称是.war文件名。同样在（）中，我的应用程序以链接形式显示：（/spring-sample-1.0-SNAPSHOT）。ArtifactId='spring sample'在pom.xml@saverwar中该war应用程序在tomcat中的部署状态是什么？我认为，您的应用程序在部署过程中有错误。还有一个问题：您将如何运行编译成Java15的应用程序，而tomcat是在Java1.8下运行的？您将获得不兼容的java版本，但您提供的视频不是英文的。另外，您不应该期望我们观看19分钟的视频来理解您作为代码所做的事情。因此，请提供足够的代码来帮助我们理解您的代码和问题，以便我们能够help@UsemeAlehosaini抱歉，现在我修复了itI下载的Java8，所以现在一切都是Java8。还是一样的问题。是的，我知道，我试着用artifactId:spring-sample3创建新项目。非常感谢你，兄弟，不客气！