Jackson Object Mapper从Java 7到Java 8的版本问题

Question

我正在尝试将Java版本升级1.7到1.8.除了在Maven插件中将目标版本升级到1.8之外,没有更改任何代码.

Error: cannot access Versioned.

资源:

private ObjectMapper mapper = new ObjectMapper();
return mapper.writeValueAsString(data);

无法在互联网上的任何地方找到任何文档.我认为1.8应该完全向后兼容.

编辑:如果我没有改变pom,如果我将我的本地maven设置为Java 8,它仍然会破坏.所以用Java 8编译有问题:(

[INFO] |  +- com.fasterxml.jackson.core:jackson-annotations:jar:2.2.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-core-asl:jar:1.1.0:compile
[INFO] +- com.fasterxml.jackson.core:jackson-core:jar:2.2.2:compile
[INFO] +- com.fasterxml:jackson-xml-databind:jar:0.6.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-mapper-asl:jar:1.9.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-xc:jar:1.9.2:compile
[INFO] +- com.fasterxml.jackson.core:jackson-databind:jar:2.2.2:compile
[INFO] |  +- com.fasterxml.jackson.core:jackson-annotations:jar:2.2.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-core-asl:jar:1.1.0:compile
[INFO] +- com.fasterxml.jackson.core:jackson-core:jar:2.2.2:compile
[INFO] +- com.fasterxml:jackson-xml-databind:jar:0.6.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-mapper-asl:jar:1.9.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-xc:jar:1.9.2:compile
[INFO] +- com.fasterxml.jackson.core:jackson-databind:jar:2.2.2:compile
[INFO] |  +- com.fasterxml.jackson.core:jackson-annotations:jar:2.2.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-core-asl:jar:1.1.0:compile
[INFO] +- com.fasterxml.jackson.core:jackson-core:jar:2.2.2:compile
[INFO] +- com.fasterxml:jackson-xml-databind:jar:0.6.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-mapper-asl:jar:1.9.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-xc:jar:1.9.2:compile
[INFO] +- com.fasterxml.jackson.core:jackson-databind:jar:2.2.2:compile
[INFO] |  +- com.fasterxml.jackson.core:jackson-annotations:jar:2.2.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-core-asl:jar:1.1.0:compile
[INFO] +- com.fasterxml.jackson.core:jackson-core:jar:2.2.2:compile
[INFO] +- com.fasterxml:jackson-xml-databind:jar:0.6.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-mapper-asl:jar:1.9.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-xc:jar:1.9.2:compile
[INFO] +- com.fasterxml.jackson.core:jackson-databind:jar:2.2.2:compile
[INFO] |  +- com.fasterxml.jackson.core:jackson-annotations:jar:2.2.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-core-asl:jar:1.1.0:compile
[INFO] |  +- org.codehaus.jackson:jackson-jaxrs:jar:1.9.11:compile
[INFO] |  +- org.codehaus.jackson:jackson-mapper-asl:jar:1.9.11:compile
[INFO] +- com.fasterxml.jackson.core:jackson-core:jar:2.2.2:compile
[INFO] +- com.fasterxml:jackson-xml-databind:jar:0.6.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-xc:jar:1.9.2:compile
[INFO] +- com.fasterxml.jackson.core:jackson-databind:jar:2.2.2:compile
[INFO] +- org.codehaus.jackson:jackson-core-asl:jar:1.9.13:compile
[INFO] |  |  +- org.codehaus.jackson:jackson-jaxrs:jar:1.9.11:compile
[INFO] |  +- com.fasterxml.jackson.core:jackson-annotations:jar:2.6.0-rc2:compile
[INFO] +- com.fasterxml.jackson.core:jackson-core:jar:2.2.2:compile
[INFO] +- com.fasterxml:jackson-xml-databind:jar:0.6.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-mapper-asl:jar:1.9.2:compile
[INFO] |  +- org.codehaus.jackson:jackson-xc:jar:1.9.2:compile
[INFO] +- com.fasterxml.jackson.core:jackson-databind:jar:2.2.2:compile

-X输出:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile) on project my-module: Compilation failure
[ERROR] /Users/xxxxxx/MyApp.java:[52,15] error: cannot access Versioned
[ERROR] -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile) on project myntra-orch-lms: Compilation failure
/Users/xxxxxx/MyApp.java:[52,15] error: cannot access Versioned

    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:212)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
    at org.apache.maven.cli.MavenCli.execute(MavenCli.java:862)
    at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:286)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:197)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.plugin.CompilationFailureException: Compilation failure
/Users/xxxxxx/MyApp.java:[52,15] error: cannot access Versioned

    at org.apache.maven.plugin.AbstractCompilerMojo.execute(AbstractCompilerMojo.java:656)
    at org.apache.maven.plugin.CompilerMojo.execute(CompilerMojo.java:128)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
    ... 20 more
[ERROR]
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException

Answer 1

看起来您正在使用非常旧的杰克逊版本的混合。我怀疑在 Java 8 中 Maven 编译器插件使用的 .jar 文件的顺序可能与 Java 7 中不同，因此Versioned可能找不到接口。这可能是一个问题，因为在 Java 8 中，java 编译器在编译实现时要求接口存在于类路径中 ( JDK-8055048 )。

该Versioned界面是在 1.6.0 中引入的，而您拥有的org.codehaus.jackson:jackson-core-asl版本是 1.1.0。这可能是问题的根本原因。

低风险修复可能是org.codehaus.jackson:jackson-core-asl通过在 .pom 文件中添加以下依赖项将版本提升到 1.9.2 以对应其他库：

<dependency>
    <groupId>org.codehaus.jackson</groupId>
    <artifactId>jackson-core-asl</artifactId>
    <version>1.9.2</version>
</dependency>

作为一个长期解决方案，我建议考虑com.fastxml.jackson在所有项目中将 Jackson 版本升级到最新的 2.X（打包在 参考资料中），并停止使用版本 1.X（打包在 参考资料中org.codehaus.jackson）。