我试图将 firebase 实时数据库与谷歌应用程序引擎应用程序集成。我在调用时收到此错误
> DatabaseReference ref = FirebaseDatabase
> .getInstance()
> .getReference("todoItems");
堆栈跟踪是
03:21:01.450 /productSync java.lang.NoSuchMethodError 错误：
com.google.common.base.Preconditions.checkState(ZLjava/lang/String;Ljava/lang/Object;)V
在
com.google.firebase.FirebaseApp.checkNotDeleted(FirebaseApp.java:314)
在 com.google.firebase.FirebaseApp.getOptions(FirebaseApp.java:260)
在
com.google.firebase.database.FirebaseDatabase.getInstance(FirebaseDatabase.java:80)
在 in.prago.servlet.ProductDataSync.doGet(ProductDataSync.java:83)
在 javax.servlet.http.HttpServlet.service(HttpServlet.java:617) 处
javax.servlet.http.HttpServlet.service(HttpServlet.java:717) 位于
org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
在
org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
在
com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:125)
在
org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
在
com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:37)
在
org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
在
com.google.apphosting.utils.servlet.JdbcMySqlConnectionCleanupFilter.doFilter(JdbcMySqlConnectionCleanupFilter.java:60)
在
org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
在
com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:48)
在
org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
在
org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
在
org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
在
org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
在
org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
在
org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
在
com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle（AppVersionHandlerMap.java:257）
在
org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
在 org.mortbay.jetty.Server.handle(Server.java:326) 处
org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
在
org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
在
com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76)
在 org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
在
com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:145)
在
com.google.apphosting.runtime.JavaRuntime$RequestRunnable.dispatchServletRequest(JavaRuntime.java:644)
在
com.google.apphosting.runtime.JavaRuntime$RequestRunnable.dispatchRequest(JavaRuntime.java:604)
在
com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:574)
在
com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:453)
在
com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:460)
在
com.google.tracing.CurrentContext.runInContext(CurrentContext.java:293)
在
com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:319)
在
com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:311)
在
com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:457)
在
com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:238)
在 java.lang.Thread.run(Thread.java:745)
许多论坛都讨论了同样的问题，人们建议将 Guava 19.0 升级到 Guava 20.0。就我而言，我没有使用任何此类库，因此我尝试添加这两个库，但它对我来说没有成功。每次都出现同样的错误。我还添加了我的 pom.xml 文件，以防有人需要查看它。任何帮助，将不胜感激。
这是一个此类论坛的链接https://github.com/google/guava/issues/2380 https://github.com/google/guava/issues/2380
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<packaging>war</packaging>
<version>1.0</version>
<properties>
<appengine.app.version>1</appengine.app.version>
<appengine.target.version>1.9.53</appengine.target.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>com.google.firebase</groupId>
<artifactId>firebase-admin</artifactId>
<version>5.0.0</version>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>20.0</version>
</dependency>
<!-- Compile/runtime dependencies -->
<dependency>
<groupId>com.google.endpoints</groupId>
<artifactId>endpoints-framework</artifactId>
<version>2.0.7</version>
</dependency>
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-api-1.0-sdk</artifactId>
<version>${appengine.target.version}</version>
</dependency>
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-endpoints</artifactId>
<version>${appengine.target.version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.inject</groupId>
<artifactId>javax.inject</artifactId>
<version>1</version>
</dependency>
<dependency>
<groupId>com.googlecode.objectify</groupId>
<artifactId>objectify</artifactId>
<version>5.0</version>
</dependency>
<dependency>
<groupId>com.google.endpoints</groupId>
<artifactId>endpoints-management-control-appengine</artifactId>
<version>1.0.0-beta.11</version>
</dependency>
<dependency>
<groupId>com.google.endpoints</groupId>
<artifactId>endpoints-framework-auth</artifactId>
<version>1.0.0-beta.11</version>
</dependency>
<!-- Test Dependencies -->
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-testing</artifactId>
<version>${appengine.target.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-api-stubs</artifactId>
<version>${appengine.target.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
</dependency>
</dependencies>
<build>
<outputDirectory>target/${project.artifactId}-${project.version}/WEB-INF/classes</outputDirectory>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<version>2.5.1</version>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
<plugin>
<groupId>com.google.cloud.tools</groupId>
<artifactId>endpoints-framework-maven-plugin</artifactId>
<version>1.0.0-beta5</version>
<configuration>
<!-- plugin configuration -->
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.3</version>
<configuration>
<webXml>${project.build.directory}/generated-sources/appengine-endpoints/WEB-INF/web.xml</webXml>
<webResources>
<resource>
<!-- this is relative to the pom.xml directory -->
<directory>${project.build.directory}/generated-sources/appengine-endpoints</directory>
<!-- the list has a default value of ** -->
<includes>
<include>WEB-INF/*.discovery</include>
<include>WEB-INF/*.api</include>
</includes>
</resource>
</webResources>
</configuration>
</plugin>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-maven-plugin</artifactId>
<version>${appengine.target.version}</version>
<configuration>
<enableJarClasses>false</enableJarClasses>
</configuration>
<executions>
<execution>
<goals>
<goal>endpoints_get_discovery_doc</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
<pluginManagement>
<plugins>
<!--This plugin's configuration is used to store Eclipse m2e settings only. It has no influence on the Maven build itself.-->
<plugin>
<groupId>org.eclipse.m2e</groupId>
<artifactId>lifecycle-mapping</artifactId>
<version>1.0.0</version>
<configuration>
<lifecycleMappingMetadata>
<pluginExecutions>
<pluginExecution>
<pluginExecutionFilter>
<groupId>
com.google.appengine
</groupId>
<artifactId>
appengine-maven-plugin
</artifactId>
<versionRange>
[1.9.3,)
</versionRange>
<goals>
<goal>
endpoints_get_discovery_doc
</goal>
</goals>
</pluginExecutionFilter>
<action>
<ignore></ignore>
</action>
</pluginExecution>
</pluginExecutions>
</lifecycleMappingMetadata>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
<groupId>in.prago</groupId>
<artifactId>prago</artifactId>
</project>
Update :
按照 Auberon 的建议，我使用新版本的 Objectify 5.1.17 更新了我的 pom.xml 并删除了番石榴依赖性。我尝试运行代码，但同样的错误再次出现。这是我的堆栈跟踪
> com.google.api.server.spi.SystemService invokeServiceMethod: exception
> occurred while calling backend method (SystemService.java:398)
>
> java.lang.NoSuchMethodError:
> com.google.common.base.Preconditions.checkState(ZLjava/lang/String;Ljava/lang/Object;)V
> at
> com.google.firebase.FirebaseApp.checkNotDeleted(FirebaseApp.java:314)
> at com.google.firebase.FirebaseApp.getOptions(FirebaseApp.java:260)
> at
> com.google.firebase.database.FirebaseDatabase.getInstance(FirebaseDatabase.java:80)
> at
> in.prago.spi.PragoMerchantApi.saveProfile(PragoMerchantApi.java:189)
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
> at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> at java.lang.reflect.Method.invoke(Method.java:42) at
> com.google.api.server.spi.SystemService.invokeServiceMethod(SystemService.java:363)
> at
> com.google.api.server.spi.SystemServiceServlet.execute(SystemServiceServlet.java:113)
> at
> com.google.api.server.spi.SystemServiceServlet.doPost(SystemServiceServlet.java:71)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) at
> javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at
> org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
> at
> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
> at
> com.googlecode.objectify.ObjectifyFilter.doFilter(ObjectifyFilter.java:48)
> at
> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
> at
> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
> at
> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
> at
> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
> at
> org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
> at
> org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
> at
> org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
> at
> org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
> at
> org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
> at
> org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
> at
> org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
> at org.mortbay.jetty.Server.handle(Server.java:326) at
> org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
> at
> org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
> at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
> at
> com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:453)
> at
> com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:460)
> at
> com.google.tracing.CurrentContext.runInContext(CurrentContext.java:293)
> at
> com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:319)
> at
> com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:311)
> at
> com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:457)
> at java.lang.Thread.run(Thread.java:745)
http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<packaging>war</packaging>
<version>1.0</version>
<properties>
<appengine.app.version>1</appengine.app.version>
<appengine.target.version>1.9.53</appengine.target.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>com.google.firebase</groupId>
<artifactId>firebase-admin</artifactId>
<version>5.0.0</version>
</dependency>
<dependency>
<groupId>com.google.endpoints</groupId>
<artifactId>endpoints-framework</artifactId>
<version>2.0.7</version>
</dependency>
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-api-1.0-sdk</artifactId>
<version>${appengine.target.version}</version>
</dependency>
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-endpoints</artifactId>
<version>${appengine.target.version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.inject</groupId>
<artifactId>javax.inject</artifactId>
<version>1</version>
</dependency>
<dependency>
<groupId>com.googlecode.objectify</groupId>
<artifactId>objectify</artifactId>
<version>5.1.17</version>
</dependency>
<dependency>
<groupId>com.google.endpoints</groupId>
<artifactId>endpoints-management-control-appengine</artifactId>
<version>1.0.0-beta.11</version>
</dependency>
<dependency>
<groupId>com.google.endpoints</groupId>
<artifactId>endpoints-framework-auth</artifactId>
<version>1.0.0-beta.11</version>
</dependency>
<!-- Test Dependencies -->
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-testing</artifactId>
<version>${appengine.target.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-api-stubs</artifactId>
<version>${appengine.target.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
</dependency>
</dependencies>
<build>
<outputDirectory>target/${project.artifactId}-${project.version}/WEB-INF/classes</outputDirectory>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<version>2.5.1</version>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
<plugin>
<groupId>com.google.cloud.tools</groupId>
<artifactId>endpoints-framework-maven-plugin</artifactId>
<version>1.0.0-beta5</version>
<configuration>
<!-- plugin configuration -->
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.3</version>
<configuration>
<webXml>${project.build.directory}/generated-sources/appengine-endpoints/WEB-INF/web.xml</webXml>
<webResources>
<resource>
<!-- this is relative to the pom.xml directory -->
<directory>${project.build.directory}/generated-sources/appengine-endpoints</directory>
<!-- the list has a default value of ** -->
<includes>
<include>WEB-INF/*.discovery</include>
<include>WEB-INF/*.api</include>
</includes>
</resource>
</webResources>
</configuration>
</plugin>
<plugin>
<groupId>com.google.appengine</groupId>
<artifactId>appengine-maven-plugin</artifactId>
<version>${appengine.target.version}</version>
<configuration>
<enableJarClasses>false</enableJarClasses>
</configuration>
<executions>
<execution>
<goals>
<goal>endpoints_get_discovery_doc</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
<pluginManagement>
<plugins>
<!--This plugin's configuration is used to store Eclipse m2e settings only. It has no influence on the Maven build itself.-->
<plugin>
<groupId>org.eclipse.m2e</groupId>
<artifactId>lifecycle-mapping</artifactId>
<version>1.0.0</version>
<configuration>
<lifecycleMappingMetadata>
<pluginExecutions>
<pluginExecution>
<pluginExecutionFilter>
<groupId>
com.google.appengine
</groupId>
<artifactId>
appengine-maven-plugin
</artifactId>
<versionRange>
[1.9.3,)
</versionRange>
<goals>
<goal>
endpoints_get_discovery_doc
</goal>
</goals>
</pluginExecutionFilter>
<action>
<ignore></ignore>
</action>
</pluginExecution>
</pluginExecutions>
</lifecycleMappingMetadata>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
<groupId>in.prago</groupId>
<artifactId>prago</artifactId>
</project>
