我与Alternator的作者就这个问题保持联系,他和我一样感到困惑。简短的故事:我编写了代码的单元测试,使用Alternator模拟框架对DynamoDB进行操作,当我从Eclipse中调用它们时工作正常,但是从maven调用时失败。
失败源于AWS SDK本身:
com.amazonaws.AmazonServiceException: [java.lang.Error: property value is null.]
at com.amazonaws.http.AmazonHttpClient.handleErrorResponse(AmazonHttpClient.java:679) ~[aws-java-sdk-1.5.5.jar:na]
at com.amazonaws.http.AmazonHttpClient.executeHelper(AmazonHttpClient.java:350) ~[aws-java-sdk-1.5.5.jar:na]
at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:202) ~[aws-java-sdk-1.5.5.jar:na]
at com.michelboudreau.alternatorv2.AlternatorDBClientV2.invoke(AlternatorDBClientV2.java:225) ~[alternator-0.6.4.jar:na]
at com.michelboudreau.alternatorv2.AlternatorDBClientV2.updateItem(AlternatorDBClientV2.java:99) ~[alternator-0.6.4.jar:na]
at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper$2.executeLowLevelRequest(DynamoDBMapper.java:646) ~[aws-java-sdk-1.5.5.jar:na]
at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper$SaveObjectHandler.execute(DynamoDBMapper.java:767) ~[aws-java-sdk-1.5.5.jar:na]
at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper.save(DynamoDBMapper.java:658) ~[aws-java-sdk-1.5.5.jar:na]
at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper.save(DynamoDBMapper.java:488) ~[aws-java-sdk-1.5.5.jar:na]
at com.somoglobal.eventdata.Controller.addDeviceKeys(Controller.java:531) ~[classes/:na]
正如您所看到的那样非常非常有用,因为堆栈跟踪本身只是在AWS SDK正在通过(模拟的)远程接收的响应汇总异常时显示堆栈服务。
相关版本号:
进一步深入了解项目的(略微省略的)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/xsd/maven-4.0.0.xsd">
<parent>
<groupId>snip</groupId>
<artifactId>snip</artifactId>
<version>1.14.2-SNAPSHOT</version>
</parent>
<artifactId>snip</artifactId>
<version>1.6.0-SNAPSHOT</version>
<name>snip</name>
<dependencies>
...snip...
<dependency>
<groupId>com.amazonaws</groupId>
<artifactId>aws-java-sdk</artifactId>
<version>1.5.5</version>
</dependency>
<dependency>
<groupId>com.michelboudreau</groupId>
<artifactId>alternator</artifactId>
<version>0.6.4</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
和略微修剪的测试:
package com.xxx;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.UUID;
import org.joda.time.DateTime;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TestRule;
import com.amazonaws.Request;
import com.amazonaws.handlers.RequestHandler;
import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper;
import com.amazonaws.services.dynamodbv2.model.AttributeDefinition;
import com.amazonaws.services.dynamodbv2.model.CreateTableRequest;
import com.amazonaws.services.dynamodbv2.model.CreateTableResult;
import com.amazonaws.services.dynamodbv2.model.KeySchemaElement;
import com.amazonaws.services.dynamodbv2.model.KeyType;
import com.amazonaws.services.dynamodbv2.model.ProvisionedThroughput;
import com.amazonaws.services.dynamodbv2.model.ProvisionedThroughputExceededException;
import com.amazonaws.util.TimingInfo;
import com.michelboudreau.alternator.AlternatorDB;
import com.michelboudreau.alternatorv2.AlternatorDBClientV2;
import com.xxx.stuff;
public class ControllerTest {
private static Controller instance;
private static DynamoDBMapper mapper;
private static AlternatorDB db;
private static AlternatorDBClientV2 client;
@BeforeClass
public static void setup() throws Exception {
client = new AlternatorDBClientV2();
mapper = new DynamoDBMapper(client);
db = new AlternatorDB().start();
// code to create dynamodb was here
instance = new Controller(mapper);
}
@AfterClass
public static void tearDown() throws Exception {
db.stop();
}
@Test
public void testAddDeviceKeys() {
Collection<DeviceKey> keys = EventDataModelMapper.getDeviceKeys(ClassFixtures.event);
assertNotNull("keys should not be null", keys);
assertFalse("keys should not be empty", keys.isEmpty());
boolean result = instance.addDeviceKeys(keys);
assertTrue("result should be true", result);
}
}
测试中的代码可能并不特别涉及此故障 - 我已经完成了足够的调试跟踪,以便在测试期间直接通过Eclipse调用以及从maven运行时执行相同的操作。
修改
实际上,Alternator 可能与此有牵连,因为有问题的错误消息可能来自com.michelboudreau.alternator.validation.ValidatorUtils:
public static <T> List<Error> rejectIfNull(T property) {
List<Error> errors = new ArrayList<Error>();
if (property == null) {
errors.add(new Error("property value is null."));
}
return errors;
}
答案 0 :(得分:1)
好的,Alternator没有错,问题最终发生在我工作场所的一把椅子和键盘之间。有问题的错误消息确实来自Alternator,并且最终源于缺少的表定义 - 由于非常复杂的原因,当测试通过Maven运行时,通过Alternator创建的模拟Dynamodb表的名称与之间存在差异。正在测试的代码试图访问的表名。
我想公开感谢Michel Boudreau在我就此事直接与他联系时花时间作出回应。
答案 1 :(得分:1)
相反,您可以在本地运行Amazon DynamoDB。
http://aws.typepad.com/aws/2013/09/dynamodb-local-for-desktop-development.html
答案 2 :(得分:1)
相反,您可以使用jcabi-dynamodb-maven-plugin
运行DynamoDB Local(我是开发人员)。