我正在尝试在 Java 9 maven 项目中使用孵化器中的 HttpClient。我没有收到任何编译问题。项目成功构建。但是当我尝试运行 Main 类时，它给了我以下异常：
Exception in thread "main" java.lang.NoClassDefFoundError: jdk/incubator/http/HttpClient
at java9.http_client.Main.main(Main.java:18)
Caused by: java.lang.ClassNotFoundException: jdk.incubator.http.HttpClient
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:185)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:496)....
我的代码只是一个模块信息文件和一个 Main 类，它只调用 google.com 并尝试读取响应：
模块信息.java
module java9.http_client {
requires jdk.incubator.httpclient;
}
主.java
public final class Main {
public static void main(String[] args) {
try {
HttpClient client = HttpClient.newHttpClient();
URI httpURI = new URI("http://www.google.com/");
HttpRequest request = HttpRequest.newBuilder(httpURI).GET().build();
HttpResponse<String> response = client.send(request, HttpResponse.BodyHandler.asString());
String responseBody = response.body();
int responseStatusCode = response.statusCode();
System.out.println(responseBody + "\n" + responseStatusCode);
} catch (URISyntaxException | IOException | InterruptedException e) {
throw new RuntimeException("Unable to run Java 9 Http Client examples", e);
}
}
}
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.javacodegeeks.java9</groupId>
<artifactId>http_client</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>Java9HttpClient</name>
<description>Java Http Client example</description>
<properties>
<java-version>1.9</java-version>
<maven-compiler-plugin-version>3.6.1</maven-compiler-plugin-version>
<maven-shade-plugin-version>3.0.0</maven-shade-plugin-version>
</properties>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven-compiler-plugin-version}</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>${maven-shade-plugin-version}</version>
</plugin>
</plugins>
</pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${java-version}</source>
<target>${java-version}</target>
<verbose>true</verbose>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<transformers>
<transformer
implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
<mainClass>com.javacodegeeks.java9.http_client.Main</mainClass>
</transformer>
</transformers>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
我错过了什么？我发现了很多关于这个的文章，但他们都是这样做的。
任何帮助都值得赞赏。谢谢！
使用 --add-modules 时执行的命令
cd /home/mansi/NetBeansProjects/java9-http-client; JAVA_HOME=/home/mansi/jdk-9 /home/mansi/netbeans-dev-201709070001/java/maven/bin/mvn "-Dexec.args=--add-modules=jdk.incubator.httpclient -classpath %classpath java9.http_client.Main" -Dexec.executable=/home/mansi/jdk-9/bin/java -Dexec.classpathScope=runtime org.codehaus.mojo:exec-maven-plugin:1.5.0:exec
不使用 --add-modules 时
cd /home/mansi/NetBeansProjects/java9-http-client; JAVA_HOME=/home/mansi/jdk-9 /home/mansi/netbeans-dev-201709070001/java/maven/bin/mvn "-Dexec.args=-classpath %classpath java9.http_client.Main" -Dexec.executable=/home/mansi/jdk-9/bin/java -Dexec.classpathScope=runtime org.codehaus.mojo:exec-maven-plugin:1.5.0:exec