Question

我想获取SQS队列中的消息。我是第一次使用maven。以下是我到目前为止所做的步骤。

1。使用此命令创建maven项目：

mvn archetype:generate -DgroupId=com.mycompany.app -DartifactId=aws-try -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

上面的命令使用src文件夹和pom.xml创建了一个 aws-try 目录。

2。在pom.xml中添加了AWS-SDK依赖项：

<dependency>
  <groupId>com.amazonaws</groupId>
  <artifactId>aws-java-sdk</artifactId>
  <version>1.11.78</version>
</dependency>

第3。在src＆gt;下添加了SQSTry.java文件主要＆gt; java＆gt; com＆gt; mycompany＆gt; app＆gt; SQSTry.java

package com.mycompany.app;

import java.util.List;
import java.util.Map.Entry;

import com.amazonaws.AmazonClientException;
import com.amazonaws.AmazonServiceException;
import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.profile.ProfileCredentialsProvider;
import com.amazonaws.regions.Region;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.sqs.AmazonSQS;
import com.amazonaws.services.sqs.AmazonSQSClient;
import com.amazonaws.services.sqs.model.CreateQueueRequest;
import com.amazonaws.services.sqs.model.DeleteMessageRequest;
import com.amazonaws.services.sqs.model.DeleteQueueRequest;
import com.amazonaws.services.sqs.model.Message;
import com.amazonaws.services.sqs.model.ReceiveMessageRequest;
import com.amazonaws.services.sqs.model.SendMessageRequest;


public class SQSTry {

public static void main (String args[]) {


System.out.println("SQSTry");

        AWSCredentials credentials = null;
        try {
            credentials = new ProfileCredentialsProvider().getCredentials();
        } catch (Exception e) {
            throw new AmazonClientException(
                    "Cannot load the credentials from the credential profiles file. " +
                    "Please make sure that your credentials file is at the correct " +
                    "location (~/.aws/credentials), and is in valid format.",
                    e);
        }

        AmazonSQS sqs = new AmazonSQSClient(credentials);
        Region apNortheast1 = Region.getRegion(Regions.AP_NORTHEAST_1);
        sqs.setRegion(apNortheast1);

        System.out.println("===========================================");
        System.out.println("Getting Started with Amazon SQS");
        System.out.println("===========================================\n");



}
}

4。现在打包命令

mvn package

上面的命令是针对aws-try目录的根目录中的pom.xml运行的。

这会出现以下错误：

Exception in thread "main" java.lang.NoClassDefFoundError: com/amazonaws/AmazonClientException
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2625)
    at java.lang.Class.getMethod0(Class.java:2866)
    at java.lang.Class.getMethod(Class.java:1676)
    at sun.launcher.LauncherHelper.getMainMethod(LauncherHelper.java:494)
    at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:486)
Caused by: java.lang.ClassNotFoundException: com.amazonaws.AmazonClientException
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    ... 6 more

我已正确添加了依赖项。如果你注意到上面的SQSTry.java文件，那么 AWSCredentials 也是来自amazon的包，但是id不会给出任何错误。

我错过了什么？

Answer 1

你能试试mvn clean install吗？还要验证您是否使用了适用于SDK的版本

尝试添加

<!-- https://mvnrepository.com/artifact/com.amazonaws/aws-java-sdk-core -->
<dependency>
    <groupId>com.amazonaws</groupId>
    <artifactId>aws-java-sdk-core</artifactId>
    <version>1.11.78</version>
</dependency>

Answer 2

您需要将 maven-shade-plugin 添加到pom.xml，它将所有AWS sdk jar打包到一个独立的jar文件中。

添加以下内容对我有用：

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <version>2.3</version>
        <configuration>
          <createDependencyReducedPom>false</createDependencyReducedPom>
        </configuration>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>shade</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>

我从here找到了这个解决方案。

如何使用AWS SDK for Java与maven？

2 个答案: