我有一个应用程序引擎项目。Here https://github.com/KevinWorkman/GoogleCloudExamples/tree/master/hello-world是一个示例存储库,但它只包含几个文件:
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>io.happycoding</groupId>
<artifactId>google-cloud-hello-world</artifactId>
<version>1</version>
<packaging>war</packaging>
<properties>
<!-- App Engine currently supports Java 8 -->
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<failOnMissingWebXml>false</failOnMissingWebXml>
</properties>
<dependencies>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-maven-plugin</artifactId>
<version>1.9.71</version>
</plugin>
</plugins>
</build>
</project>
appengine-web.xml
<?xml version="1.0" encoding="utf-8"?>
<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
<application>MY_PROJECT_ID_HERE</application>
<version>1</version>
<threadsafe>false</threadsafe>
<sessions-enabled>true</sessions-enabled>
<runtime>java8</runtime>
</appengine-web-app>
HelloWorldServlet.java
package io.happycoding.servlets;
import java.io.IOException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/hello")
public class HelloWorldServlet extends HttpServlet {
@Override
public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
response.setContentType("text/html;");
response.getOutputStream().println("<h1>Hello world!</h1>");
}
}
我没有 web.xml 文件因为我正在使用@WebServlet
改为注释。多年来,这一直非常有效。
唯一的问题是我只能使用 Java 8,所以我很高兴看到 App Engineannounce https://cloud.google.com/blog/products/application-development/turn-it-up-to-eleven-java-11-runtime-comes-to-app-engine对 Java 11 的支持。我现在正在尝试将我的 App Engine 项目升级到 Java 11。
我首先改变了appengine-web.xml
文件包含这一行:
<runtime>java11</runtime>
我也改变了pom.xml
file:
<maven.compiler.source>11</maven.compiler.source>
<maven.compiler.target>11</maven.compiler.target>
I run mvn appengine:devserver
(在此更改之前工作正常),我收到此错误:
ClassLoader is jdk.internal.loader.ClassLoaders$AppClassLoader@78308db1, not a URLClassLoader.
I gather https://stackoverflow.com/questions/55490900/unable-to-build-bookshelf-app-for-java-on-app-engine-standard-environment-exam这是因为 App Engine Maven 插件本身需要 Java 8。我还了解到App Engine Maven 插件已弃用 https://cloud.google.com/appengine/docs/standard/java/tools/migrate-maven,并且我应该升级到 Cloud SDK Maven 插件。好的。
我跟随本指南 https://cloud.google.com/appengine/docs/standard/java11/using-maven我改变了我的插件pom.xml
文件到此:
<plugin>
<groupId>com.google.cloud.tools</groupId>
<artifactId>appengine-maven-plugin</artifactId>
<version>2.2.0</version>
</plugin>
然后我跑mvn package appengine:run
(当然,因为运行开发服务器的命令也发生了变化),但现在我收到此错误:
java.io.FileNotFoundException: /home/kevin/gcloud-tutorials/hello-world/target/hello-world-1/WEB-INF/web.xml (No such file or directory)
该错误表示找不到web.xml
文件,但我不需要这个文件,因为我正在使用@WebServlet
注解!我的pom.xml
文件还包含一个<failOnMissingWebXml>false</failOnMissingWebXml>
属性,但我不知道这是否对新插件有任何作用。
我错过了一个步骤或财产吗?如何升级我的 App Engine 项目以使用 Java 11,而不需要web.xml
file?