java - Log4j2 无法使用 json 配置文件

Question

看起来 log4j 正在尝试通过 XML 解析器解析 .json 配置文件，但为什么呢？

我通过命令行参数设置 log4j 配置文件:

-Dlog4j.configurationFile=src/log4j2.json

文件内容:

{
    "configuration": {
        "appenders": {
            "Console": {
                "name": "Console",
                "target": "SYSTEM_OUT",
                "PatternLayout": {
                    "pattern": "%date %thread %logger %message"
                }
            }
        },
        "loggers": {
            "root": {
                "level": "debug",
                "appender-ref": {
                    "ref": "Console"
                }
            }
        }
    }
}

我得到了什么:

[Fatal Error] log4j2.json:1:1: Content is not allowed in prolog.
ERROR StatusLogger Error parsing D:\Dev\HDelphiCrawler\src\log4j2.json org.xml.sax.SAXParseException; systemId: file:///D:/Dev/HDelphiCrawler/src/log4j2.json; lineNumber: 1; columnNumber: 1; Content is not allowed in prolog.
    at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:257)
    at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:348)
    at org.apache.logging.log4j.core.config.xml.XmlConfiguration.<init>(XmlConfiguration.java:140)
    at org.apache.logging.log4j.core.config.xml.XmlConfigurationFactory.getConfiguration(XmlConfigurationFactory.java:44)
    at org.apache.logging.log4j.core.config.ConfigurationFactory$Factory.getConfiguration(ConfigurationFactory.java:410)
    ....and so on...
ERROR StatusLogger No logging configuration

我的 lib 文件夹中的 jar:

• hamcrest-junit-2.0.0.0.jar
• jackson-annotations-2.6.1.jar
• jackson-core-2.6.1.jar
• jackson-databind-2.6.1.jar
• java-hamcrest-2.0.0.0.jar
• junit-4.12.jar
• kotlin-reflect.jar
• kotlin-runtime-sources.jar
• kotlin-runtime.jar
• log4j-api-2.3.jar
• log4j-core-2.3.jar
• log4j-slf4j-impl-2.3.jar

Answer 1

即使已经有一个被接受的答案，我也会发布我的解决方案。也许这对将来的其他人有帮助......

它对我不起作用的原因是我没有可用的 jackson-core 和 jackson-databind 库。添加后

compile 'com.fasterxml.jackson.core:jackson-core:2.8.7'
compile 'com.fasterxml.jackson.core:jackson-databind:2.6.2'

到我的build.gradle文件，一切正常。