“SLF4J 日志绑定”的版本间的差异
		
		
		
		
		
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| Jihongchang(讨论 | 贡献) | Jihongchang(讨论 | 贡献)  | ||
| 第13行: | 第13行: | ||
| [[文件:SLF4J 日志绑定.png|无|缩略图|1271x1271像素]] | [[文件:SLF4J 日志绑定.png|无|缩略图|1271x1271像素]] | ||
| − | ===  | + | === 示例 绑定 logback 日志实现 === | 
| + | |||
| + | ==== pom.xml ==== | ||
| + | <syntaxhighlight lang="xml"> | ||
| + | <?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> | ||
| + | |||
| + |     <groupId>io.github.jihch</groupId> | ||
| + |     <artifactId>slf4j-demo</artifactId> | ||
| + |     <version>1.0-SNAPSHOT</version> | ||
| + | |||
| + |     <properties> | ||
| + |         <maven.compiler.source>8</maven.compiler.source> | ||
| + |         <maven.compiler.target>8</maven.compiler.target> | ||
| + |     </properties> | ||
| + | |||
| + |     <dependencies> | ||
| + |         <!-- slf4j 日志门面 --> | ||
| + |         <dependency> | ||
| + |             <groupId>org.slf4j</groupId> | ||
| + |             <artifactId>slf4j-api</artifactId> | ||
| + |             <version>1.7.27</version> | ||
| + |         </dependency> | ||
| + | |||
| + |         <!-- slf4j 内置的简单实现 --> | ||
| + |         <dependency> | ||
| + |             <groupId>org.slf4j</groupId> | ||
| + |             <artifactId>slf4j-simple</artifactId> | ||
| + |             <version>1.7.21</version> | ||
| + |         </dependency> | ||
| + | |||
| + |         <!-- logback 日志实现 --> | ||
| + |         <dependency> | ||
| + |             <groupId>ch.qos.logback</groupId> | ||
| + |             <artifactId>logback-classic</artifactId> | ||
| + |             <version>1.2.3</version> | ||
| + |         </dependency> | ||
| + | |||
| + |         <dependency> | ||
| + |             <groupId>junit</groupId> | ||
| + |             <artifactId>junit</artifactId> | ||
| + |             <version>4.12</version> | ||
| + |         </dependency> | ||
| + |     </dependencies> | ||
| + | |||
| + | </project> | ||
| + | </syntaxhighlight> | ||
| + | |||
| + | ==== SLF4JTest.java ==== | ||
| + | <syntaxhighlight lang="java"> | ||
| + | import org.junit.Test; | ||
| + | import org.slf4j.Logger; | ||
| + | import org.slf4j.LoggerFactory; | ||
| + | |||
| + | public class SLF4JTest { | ||
| + | |||
| + |     public static final Logger LOGGER = LoggerFactory.getLogger(SLF4JTest.class); | ||
| + | |||
| + |     @Test | ||
| + |     public void test() { | ||
| + |         // 日志输出 | ||
| + |         LOGGER.error("error"); | ||
| + |         LOGGER.warn("warn"); | ||
| + |         LOGGER.info("info"); | ||
| + |         LOGGER.debug("debug"); | ||
| + |         LOGGER.trace("trace"); | ||
| + | |||
| + |         // 使用占位符输出日志信息 | ||
| + |         String name = "jihch"; | ||
| + |         Integer age = 14; | ||
| + |         LOGGER.info("用户:{},{}", name, age); | ||
| + | |||
| + |         // 将系统的异常信息输出 | ||
| + |         try { | ||
| + |             int i = 1/0; | ||
| + |         } catch (Exception e) { | ||
| + | //            e.printStackTrace(); | ||
| + |             LOGGER.error("出现异常:", e); | ||
| + |         } | ||
| + | |||
| + |     } | ||
| + | |||
| + | } | ||
| + | </syntaxhighlight><syntaxhighlight lang="console"> | ||
| + | SLF4J: Class path contains multiple SLF4J bindings. | ||
| + | SLF4J: Found binding in [jar:file:/I:/maven_repository/org/slf4j/slf4j-simple/1.7.21/slf4j-simple-1.7.21.jar!/org/slf4j/impl/StaticLoggerBinder.class] | ||
| + | SLF4J: Found binding in [jar:file:/I:/maven_repository/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.SimpleLoggerFactory] | ||
| + | [main] ERROR io.github.jihch.SLF4JTest - error | ||
| + | [main] WARN io.github.jihch.SLF4JTest - warn | ||
| + | [main] INFO io.github.jihch.SLF4JTest - info | ||
| + | [main] INFO io.github.jihch.SLF4JTest - 用户:jihch,14 | ||
| + | [main] ERROR io.github.jihch.SLF4JTest - 出现异常: | ||
| + | java.lang.ArithmeticException: / by zero | ||
| + | 	at io.github.jihch.SLF4JTest.test(SLF4JTest.java:27) | ||
| + | 	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:498) | ||
| + | 	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50) | ||
| + | 	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) | ||
| + | 	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47) | ||
| + | 	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) | ||
| + | 	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325) | ||
| + | 	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78) | ||
| + | 	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57) | ||
| + | 	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) | ||
| + | 	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) | ||
| + | 	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) | ||
| + | 	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) | ||
| + | 	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) | ||
| + | 	at org.junit.runners.ParentRunner.run(ParentRunner.java:363) | ||
| + | 	at org.junit.runner.JUnitCore.run(JUnitCore.java:137) | ||
| + | 	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69) | ||
| + | 	at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38) | ||
| + | 	at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11) | ||
| + | 	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35) | ||
| + | 	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235) | ||
| + | 	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54) | ||
| + | |||
| + | Process finished with exit code 0 | ||
| + | |||
| + | </syntaxhighlight>在 pom.xml 加入了对 logback 的依赖:<syntaxhighlight lang="xml"> | ||
| + |         <!-- logback 日志实现 --> | ||
| + |         <dependency> | ||
| + |             <groupId>ch.qos.logback</groupId> | ||
| + |             <artifactId>logback-classic</artifactId> | ||
| + |             <version>1.2.3</version> | ||
| + |         </dependency> | ||
| + | </syntaxhighlight>只需要引入 logback-classic,因为依赖传递,就不需要再添加对 logback-core 的依赖 | ||
| + | [[文件:Logback 依赖传递.png|无|缩略图|437x437像素]] | ||
2023年2月26日 (日) 11:21的版本
https://www.bilibili.com/video/BV1iJ411H74S?p=23
SLF4J 支持各种日志框架。SLF4J 发行版附带了几个称为“SLF4J绑定”的 jar 文件,每个绑定对应一个受支持的框架。
使用 SLF4J 的日志绑定流程:
- 添加 slf4j-api 的依赖
- 使用 SLF4J 的 API 在项目中进行统一的日志记录
- 绑定具体的日志实现框架
- 绑定已经实现了 SLF4J 的日志框架,直接添加对应依赖
- 绑定没有实现 SLF4J 的日志框架,先添加日志的适配器,再添加实现类的依赖
 
- SLF4J 有且仅有一个日志实现框架的绑定(如果出现多个默认使用第一个依赖日志实现)
示例 绑定 logback 日志实现
pom.xml
<?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>
    <groupId>io.github.jihch</groupId>
    <artifactId>slf4j-demo</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>
    <dependencies>
        <!-- slf4j 日志门面 -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.27</version>
        </dependency>
        <!-- slf4j 内置的简单实现 -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-simple</artifactId>
            <version>1.7.21</version>
        </dependency>
        <!-- logback 日志实现 -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
    </dependencies>
</project>
SLF4JTest.java
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class SLF4JTest {
    public static final Logger LOGGER = LoggerFactory.getLogger(SLF4JTest.class);
    @Test
    public void test() {
        // 日志输出
        LOGGER.error("error");
        LOGGER.warn("warn");
        LOGGER.info("info");
        LOGGER.debug("debug");
        LOGGER.trace("trace");
        // 使用占位符输出日志信息
        String name = "jihch";
        Integer age = 14;
        LOGGER.info("用户:{},{}", name, age);
        // 将系统的异常信息输出
        try {
            int i = 1/0;
        } catch (Exception e) {
//            e.printStackTrace();
            LOGGER.error("出现异常:", e);
        }
    }
}
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/I:/maven_repository/org/slf4j/slf4j-simple/1.7.21/slf4j-simple-1.7.21.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/I:/maven_repository/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.SimpleLoggerFactory]
[main] ERROR io.github.jihch.SLF4JTest - error
[main] WARN io.github.jihch.SLF4JTest - warn
[main] INFO io.github.jihch.SLF4JTest - info
[main] INFO io.github.jihch.SLF4JTest - 用户:jihch,14
[main] ERROR io.github.jihch.SLF4JTest - 出现异常:
java.lang.ArithmeticException: / by zero
	at io.github.jihch.SLF4JTest.test(SLF4JTest.java:27)
	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:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
	at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
Process finished with exit code 0
在 pom.xml 加入了对 logback 的依赖:
        <!-- logback 日志实现 -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>
只需要引入 logback-classic,因为依赖传递,就不需要再添加对 logback-core 的依赖

