请求的资源不可用错误：Rest Jersey (Eclipse)答案

【问题标题】：The requested resource is not available error: Rest Jersey (Eclipse)请求的资源不可用错误：Rest Jersey (Eclipse)
【发布时间】：2018-02-07 12:48:09
【问题描述】：

我一直在尝试使用 jersey、tomcat 和 eclipse 处理 Rest 应用程序，但我收到 404 错误（请求的资源不可用。）我确实遇到了所有类似的错误，但我无法解决这个问题。

这是我的 web.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- This web.xml file is not required when using Servlet 3.0 container,
     see implementation details http://jersey.java.net/nonav/documentation/latest/jax-rs.html -->
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    <servlet>
        <servlet-name>Jersey Web Application</servlet-name>
        <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
        <init-param>
            <param-name>jersey.config.server.provider.packages</param-name>
            <param-value>org.kushal.rest.testRest</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>Jersey Web Application</servlet-name>
        <url-pattern>/webapi/*</url-pattern>
    </servlet-mapping>
</web-app>

我交叉检查了 servlet 名称，它是匹配的。我尝试使用 jdk 1.7 和 tomcat 7 以及 jdk 1.8 和 tomcat 8 以及不同版本的球衣，我尝试的最新版本是 2.25。

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/maven-v4_0_0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>org.kushal.rest</groupId>
    <artifactId>testRest</artifactId>
    <packaging>war</packaging>
    <version>0.0.1-SNAPSHOT</version>
    <name>testRest</name>

    <build>
        <finalName>testRest</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.5.1</version>
                <inherited>true</inherited>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.glassfish.jersey</groupId>
                <artifactId>jersey-bom</artifactId>
                <version>${jersey.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>org.glassfish.jersey.containers</groupId>
            <artifactId>jersey-container-servlet-core</artifactId>
            <!-- use the following artifactId if you don't need servlet 2.x compatibility -->
            <!-- artifactId>jersey-container-servlet</artifactId -->
        </dependency>
        <!-- uncomment this to get JSON support
        <dependency>
            <groupId>org.glassfish.jersey.media</groupId>
            <artifactId>jersey-media-moxy</artifactId>
        </dependency>
        -->
    </dependencies>
    <properties>
        <jersey.version>2.25</jersey.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
</project>

这是我的 resource.java 文件

package org.kushal.rest.testRest;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

/**
 * Root resource (exposed at "myresource" path)
 */
@Path("/myresource")
public class MyResource {

    /**
     * Method handling HTTP GET requests. The returned object will be sent
     * to the client as "text/plain" media type.
     *
     * @return String that will be returned as a text/plain response.
     */
    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String getIt() {
        return "Got it!";
    }
}

http://localhost:8080/testRest/myresource http://localhost:8080/testRest 请让我知道我做错了什么，因为我在过去 3 天被卡住了。

here are the logs:

Aug 29, 2017 5:11:03 PM org.apache.tomcat.util.digester.SetPropertiesRule begin
WARNING: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:messenger' did not find a matching property.
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server version:        Apache Tomcat/8.0.39
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server built:          Nov 9 2016 08:48:39 UTC
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server number:         8.0.39.0
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Name:               Windows 10
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Version:            10.0
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Architecture:          amd64
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Java Home:             C:\Program Files\Java\jre1.8.0_91
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Version:           1.8.0_91-b15
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Vendor:            Oracle Corporation
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_BASE:         C:\Users\kushaldileep\New_Rest\.metadata\.plugins\org.eclipse.wst.server.core\tmp0
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_HOME:         C:\Courses\273\apache-tomcat-8.0.39
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.base=C:\Users\kushaldileep\New_Rest\.metadata\.plugins\org.eclipse.wst.server.core\tmp0
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.home=C:\Courses\273\apache-tomcat-8.0.39
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dwtp.deploy=C:\Users\kushaldileep\New_Rest\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Djava.endorsed.dirs=C:\Courses\273\apache-tomcat-8.0.39\endorsed
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dfile.encoding=Cp1252
Aug 29, 2017 5:11:03 PM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: C:\Program Files\Java\jre1.8.0_91\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:/Program Files/Java/jre1.8.0_91/bin/server;C:/Program Files/Java/jre1.8.0_91/bin;C:/Program Files/Java/jre1.8.0_91/lib/amd64;C:\ProgramData\Oracle\Java\javapath;C:\Program Files (x86)\CodeBlocks\MinGW\bin;C:\Program Files (x86)\Brackets\command;C:\Program Files\Java\jdk1.8.0_65\bin;C:\Program Files (x86)\GtkSharp\2.12\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\Program Files\Git\cmd;C:\Program Files (x86)\Skype\Phone\;C:\Program Files\nodejs\;C:\Program Files\MySQL\MySQL Utilities 1.6\;C:\Users\kushaldileep\AppData\Local\Programs\Python\Python36-32\Scripts\;C:\Users\kushaldileep\AppData\Local\Programs\Python\Python36-32\;C:\Users\kushaldileep\Anaconda2;C:\Users\kushaldileep\Anaconda2\Scripts;C:\Users\kushaldileep\Anaconda2\Library\bin;C:\Users\kushaldileep\AppData\Roaming\npm;C:\Users\kushaldileep\AppData\Local\Microsoft\WindowsApps;;C:\Courses\273\Enide-2015-7-windows-x64-20150706\eclipse;;.
Aug 29, 2017 5:11:03 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-nio-8080"]
Aug 29, 2017 5:11:03 PM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
INFO: Using a shared selector for servlet write/read
Aug 29, 2017 5:11:03 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["ajp-nio-8009"]
Aug 29, 2017 5:11:03 PM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
INFO: Using a shared selector for servlet write/read
Aug 29, 2017 5:11:03 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 1636 ms
Aug 29, 2017 5:11:04 PM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
Aug 29, 2017 5:11:04 PM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/8.0.39
Aug 29, 2017 5:11:04 PM org.apache.catalina.util.SessionIdGeneratorBase createSecureRandom
INFO: Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [101] milliseconds.
Aug 29, 2017 5:11:04 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-nio-8080"]
Aug 29, 2017 5:11:04 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["ajp-nio-8009"]
Aug 29, 2017 5:11:04 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in 901 ms

【问题讨论】：

testRest/webapi/myresource。看起来 web.xml url 模式。这是网址的一部分。
你有日志吗？例如，对于 tomcat，检查 catalina.out 和 localhost_access 日志以及部署到它的应用程序会很有用。
@peeskillet 我试过这个localhost:8080/messenger/webapi/myresource 仍然显示相同。
@SergeiSirik：我刚刚在新工作区中创建了一个新的 Maven 项目以再次检查我已在问题中附加了日志
尝试访问localhost:8080/testRest/webapi/myresource URL

标签： java eclipse rest tomcat jersey-2.0

【解决方案1】：

我认为您需要更改 pom.xml 的创建方式，首先我开始使用您的 pom.xml 但它给了我同样的错误。

不要尝试这个，pom.xml 是基于 maven 存储库和依赖项创建的，我可以检测到它们是您项目的必需项。这是一步一步的（在这种情况下，我使用的是 Eclipse Oxygen、Tomcat 9、java 8）

打开 Eclipse
文件 > 新建 > 动态 Web 项目
2.1 项目名称：my-jersey-project
点击完成
右键单击my-jersey-project > 配置 > 转换为 Maven 项目
4.1 群号：org.jersey.demo.project
4.2 点击完成
在</build> 部分添加此依赖项后打开 pom.xml

依赖关系：

<dependencies>
    <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.core/jersey-server -->
    <dependency>
        <groupId>org.glassfish.jersey.core</groupId>
        <artifactId>jersey-server</artifactId>
        <version>2.25.1</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.core/jersey-common -->
    <dependency>
        <groupId>org.glassfish.jersey.core</groupId>
        <artifactId>jersey-common</artifactId>
        <version>2.25.1</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.containers/jersey-container-servlet -->
    <dependency>
        <groupId>org.glassfish.jersey.containers</groupId>
        <artifactId>jersey-container-servlet</artifactId>
        <version>2.25.1</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.glassfish.jersey.containers/jersey-container-servlet-core -->
    <dependency>
        <groupId>org.glassfish.jersey.containers</groupId>
        <artifactId>jersey-container-servlet-core</artifactId>
        <version>2.25.1</version>
    </dependency>
</dependencies>

展开my-jersey-project项目并右键单击部署描述符：my-jersey-project > 选择生成部署描述符存根
打开刚刚从上一步创建的web.xml，

是web.xml的内容

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">
  <display-name>my-jersey-project</display-name>
 <servlet>
    <servlet-name>Jersey REST Service</servlet-name>
    <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
     <!-- Register resources and providers under com.vogella.jersey.first package. -->
    <init-param>
        <param-name>jersey.config.server.provider.packages</param-name>
        <param-value>org.jersey.demo.project</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>Jersey REST Service</servlet-name>
    <url-pattern>/rest/*</url-pattern>
  </servlet-mapping>
  </web-app>

转到src文件夹，并创建一个名为org.jersey.demo.project的新包
在org.jersey.demo.project 中创建一个名为Hello 的新java 类

是Hello类的内容

package org.jersey.demo.project;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.core.Response;

@Path("/hello")
public class Hello {

    @GET
    @Path("/{param}")
    public Response getMsg(@PathParam("param") String msg) {

        String output = "Hello Jersey this is the param value: " + msg;

        return Response.status(200).entity(output).build();

    }

}

这一步很重要

右击my-jersey-project>Maven>更新项目，确保my-jersey-project被选中>点击确定，等一下maven依赖项已正确加载到您的项目中。
在my-jersey-project上右击>运行方式>在服务器上运行>选择tomcat服务器（假设你的eclipse上已经配置了tomcat服务器）>点击完成
终于试试你的休息服务：http://localhost:8080/my-jersey-project/rest/hello/hijersey
这是我从测试中得到的输出：Hello Jersey 这是参数值：hijersey

希望这些信息对您有所帮助。

【讨论】：

非常感谢丹尼尔。但是我收到了这个错误：org.glassfish.jersey.servlet.ServletContainer ClassNotFoundException 所以我做了以下设置：项目属性 -> 部署程序集 -> 添加 -> Java 构建路径条目 -> Gradle 依赖项 -> 完成。
话虽如此，我只是想知道。为什么无法正常创建 maven 项目？？
其实我第一次换了pom.xml就得到了ClassNotFoundException我注意到eclipse没有完成Building Workspace的任务，然后我重启eclipse并右键点击project > maven > update项目，然后当我看到构建工作区任务完成时，我以服务器身份运行并开始工作。有时当这种情况发生在我身上时，我也会删除我的整个.m2 repo 并重新开始，我不知道 Eclipse 的这种行为的根本原因可能是我的电脑。
顺便问一下，它在你的电脑上能用吗？我的意思是球衣休息服务，休息调用是否成功？
是的，我在我的电脑上工作，我确实在调用方面取得了成功，并且还创建了更多资源。

【解决方案2】：

好的，我刚刚构建了你的包并将war文件复制到tomcatwebapps目录，这个端点localhost:8080/testRest/webapi/myresource工作。这是关于 testRest.war 部署的 catalina.out sn-p：

30-Aug-2017 12:21:52.872 INFO [main] org.apache.catalina.core.AprLifecycleListener.lifecycleEvent The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: /Users/ssiryk/Library/Java/Extensions:/Library/Java/Extensions:/Network/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java:.
30-Aug-2017 12:21:53.020 INFO [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["http-nio-8080"]
30-Aug-2017 12:21:53.052 INFO [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read
30-Aug-2017 12:21:53.056 INFO [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["http-nio-8000"]
30-Aug-2017 12:21:53.056 INFO [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read
30-Aug-2017 12:21:53.057 INFO [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["https-jsse-nio-8443"]
30-Aug-2017 12:21:53.310 INFO [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read
30-Aug-2017 12:21:53.310 INFO [main] org.apache.coyote.AbstractProtocol.init Initializing ProtocolHandler ["ajp-nio-8009"]
30-Aug-2017 12:21:53.312 INFO [main] org.apache.tomcat.util.net.NioSelectorPool.getSharedSelector Using a shared selector for servlet write/read
30-Aug-2017 12:21:53.313 INFO [main] org.apache.catalina.startup.Catalina.load Initialization processed in 883 ms
30-Aug-2017 12:21:53.342 INFO [main] org.apache.catalina.core.StandardService.startInternal Starting service Catalina
30-Aug-2017 12:21:53.342 INFO [main] org.apache.catalina.core.StandardEngine.startInternal Starting Servlet Engine: Apache Tomcat/8.5.11
**30-Aug-2017 12:21:53.368 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployWAR Deploying web application archive /Applications/apache-tomcat-8.5.11/webapps/testRest.war
30-Aug-2017 12:21:54.119 INFO [localhost-startStop-1] 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.
30-Aug-2017 12:21:54.959 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployWAR Deployment of web application archive /Applications/apache-tomcat-8.5.11/webapps/testRest.war has finished in 1,590 ms**
30-Aug-2017 12:21:54.960 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deploying web application directory /Applications/apache-tomcat-8.5.11/webapps/docs
30-Aug-2017 12:21:54.972 INFO [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory Deployment of web application directory /Applications/apache-tomcat-8.5.11/webapps/docs has finished in 12 ms

我标记了有关testRest.war 部署的行。希望这会有所帮助！

【讨论】：