今天启动springboot 遇到这个么错误
Connected to the target VM, address: '127.0.0.1:10568', transport:
'socket' SLF4J: Class path contains multiple SLF4J bindings. SLF4J:
Found binding in
[jar:file:/D:/java/java_workSpace/WeixinKaipiao/lib/baiwang-bopsdk-1.3.0.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in
[jar:file:/D:/java/apache-maven-3.6.0-bin/apache-maven-3.6.0/respontry/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an
explanation. SLF4J: Actual binding is of type
[org.slf4j.impl.Log4jLoggerFactory] Exception in thread "main"
java.lang.IllegalArgumentException: LoggerFactory is not a Logback
LoggerContext but Logback is on the classpath. Either remove Logback
or the competing implementation (class
org.slf4j.impl.Log4jLoggerFactory loaded from
file:/D:/java/java_workSpace/WeixinKaipiao/lib/baiwang-bopsdk-1.3.0.jar).
If you are using WebLogic you will need to add 'org.slf4j' to
prefer-application-packages in WEB-INF/weblogic.xml:
org.slf4j.impl.Log4jLoggerFactory at
org.springframework.util.Assert.instanceCheckFailed(Assert.java:637)
at org.springframework.util.Assert.isInstanceOf(Assert.java:537)
原因
大致看了看也能猜到一二，在类路径中 Found binding 2次 SLF4J 日志接口。
经查官方日志文档：
SLF4J API is designed to bind with one and only one underlying logging framework at a time. If more than one binding is present on the class path, SLF4J will emit a warning, listing the location of those bindings.
When multiple bindings are available on the class path, select one and only one binding you wish to use, and remove the other bindings. For example, if you have both slf4j-simple-1.8.0-beta4.jar and slf4j-nop-1.8.0-beta4.jar on the class path and you wish to use the nop (no-operation) binding, then remove slf4j-simple-1.8.0-beta4.jar from the class path.
The list of locations that SLF4J provides in this warning usually provides sufficient information to identify the dependency transitively pulling in an unwanted SLF4J binding into your project. In your project's pom.xml file, exclude this SLF4J binding when declaring the unscrupulous dependency. For example, cassandra-all version 0.8.1 declares both log4j and slf4j-log4j12 as compile-time dependencies. Thus, when you include cassandra-all as a dependency in your project, the cassandra-all declaration will cause both slf4j-log4j12.jar and log4j.jar to be pulled in as dependencies. In case you do not wish to use log4j as the the SLF4J backend, you can instruct Maven to exclude these two artifacts as shown next:
<dependencies>
<dependency>
<groupId> org.apache.cassandra</groupId>
<artifactId>cassandra-all</artifactId>
<version>0.8.1</version>
<exclusions>
<exclusion>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</exclusion>
<exclusion>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
NOTE The warning emitted by SLF4J is just that, a warning. Even when multiple bindings are present, SLF4J will pick one logging framework/implementation and bind with it. The way SLF4J picks a binding is determined by the JVM and for all practical purposes should be considered random. As of version 1.6.6, SLF4J will name the framework/implementation class it is actually bound to.
Embedded components such as libraries or frameworks should not declare a dependency on any SLF4J binding but only depend on slf4j-api. When a library declares a compile-time dependency on a SLF4J binding, it imposes that binding on the end-user, thus negating SLF4J's purpose. When you come across an embedded component declaring a compile-time dependency on any SLF4J binding, please take the time to contact the authors of said component/library and kindly ask them to mend their ways.
给出引用依赖，但是我的引用外部jar 和 springboot本身的slf4j 冲突，这个依赖不能解决我的问题。
所以最后将jar或者 springboot本身的slf4j 去除一个，可以解决。
jar 又得重新编译打包，麻烦，果断去除sb本身的slf4j 。
解决办法：
starter-web 启动依赖中剔除slf4j
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
</exclusion>
</exclusions>
或者添加依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
启动会以jar的默认日志级别启动。
然后成功启动！
SLF4J 文档 ： http://www.slf4j.org/codes.html#multiple_bindings
