Question

我正在尝试使用Gradle，文件看起来像：

// Apply the java plugin to add support for Java
apply plugin: 'java'

// In this section you declare where to find the dependencies of your project
repositories {
    // Use 'jcenter' for resolving your dependencies.
    // You can declare any Maven/Ivy/file repository here.
    mavenCentral()
    jcenter()
}

jar {
    manifest {
        attributes 'Main-Class': 'execute.Entry'
    }
}

// In this section you declare the dependencies for your production and test code
dependencies {
    // The production code uses the SLF4J logging API at compile time
    compile 'org.slf4j:slf4j-api:1.7.12'
    compile 'org.apache.logging.log4j:log4j:2.3'

    // Declare the dependency for your favourite test framework you want to use in your tests.
    // TestNG is also supported by the Gradle Test task. Just change the
    // testCompile dependency to testCompile 'org.testng:testng:6.8.1' and add
    // 'test.useTestNG()' to your build script.
    testCompile 'junit:junit:4.12'
}

如您所见，我添加了两个依赖项，并希望在类

中使用

package execute;

import message.*;
import org.apache.log4j.Logger;

public class Entry {

    public static void main(String[] args) {

        Service s = new Service();
        String msg = s.GetMessage();
        LOGGER.info("Received msg: " + msg);

    }
}

当我执行语句gradle assemble时，我遇到了编译错误。

D:\Java\entrypoint\src\main\java\execute\Entry.java:4: error: package org.apache.log4j does not exist
import org.apache.log4j.Logger;
                       ^
D:\Java\entrypoint\src\main\java\execute\Entry.java:12: error: cannot find symbol
        LOGGER.info("Received msg: " + msg);
        ^
  symbol:   variable LOGGER
  location: class Entry
2 errors
:compileJava FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':compileJava'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Total time: 6.261 secs
Compilation failed; see the compiler error output for details.

我做错了什么？

更新我把我的代码更改为：

package execute;

import message.*;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.LogManager;

public class Entry {

    private static final Logger logger = LogManager.getLogger("HelloWorld");

    public static void main(String[] args) {

        Service s = new Service();
        String msg = s.GetMessage();
        logger.info("Hello, World!");

    }
}

编译器抱怨：

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/logging/log4j/LogManager
        at execute.Entry.<clinit>(Entry.java:9)
Caused by: java.lang.ClassNotFoundException: org.apache.logging.log4j.LogManager
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 1 more

更新2
执行后：

>gradle dependencies
:dependencies                                                                    

------------------------------------------------------------
Root project                 
------------------------------------------------------------

archives - Configuration for archive artifacts.
No dependencies                                                   

compile - Compile classpath for source set 'main'.
\--- org.apache.logging.log4j:log4j-api:2.3                      

default - Configuration for default artifacts.
\--- org.apache.logging.log4j:log4j-api:2.3                      

runtime - Runtime classpath for source set 'main'.
\--- org.apache.logging.log4j:log4j-api:2.3                      

testCompile - Compile classpath for source set 'test'.
+--- org.apache.logging.log4j:log4j-api:2.3                          
\--- junit:junit:4.12        
     \--- org.hamcrest:hamcrest-core:1.3

testRuntime - Runtime classpath for source set 'test'.
+--- org.apache.logging.log4j:log4j-api:2.3                          
\--- junit:junit:4.12        
     \--- org.hamcrest:hamcrest-core:1.3

BUILD SUCCESSFUL

Answer 1

您似乎还需要log4j依赖项：compile: 'log4j:log4j:versionX'

更新1 ：

当然，您应该添加：

private static final Logger logger = Logger.getLogger(DrglMutatieBerichtMdb.class);

更新2 ：

我使用以下依赖项：

compile 'log4j:log4j:1.2.17'
compile 'org.slf4j:slf4j-api:1.7.5'
compile 'org.slf4j:slf4j-log4j12:1.7.5'

比我导入的代码：

import org.apache.log4j.Logger;

并使用这样的记录器：

private static final Logger logger = Logger.getLogger(DrglMutatieBerichtMdb.class);

private static void testLogger(){
    logger.debug("The logger works!");
}

Answer 2

而不是

import org.apache.log4j.Logger;

使用

import org.apache.logging.log4j.Logger;

并定义LOGGER的实例

private static final Logger LOGGER = LogManager.getLogger("HelloWorld");

请参阅此示例 http://logging.apache.org/log4j/2.x/manual/api.html

这与Gradle没什么关系

Answer 3

我还必须添加依赖项：

compile "org.apache.logging.log4j:log4j-api:2.3"

Answer 4

第一个答案 (@helox) 帮助解决了类似的问题，我使用了 gradle 7.1.1 和下面的代码片段解决了由于找不到“org.apache.log4j 的包而导致的无法找到 Logger 错误的符号” .记录器”

testImplementation 'org.slf4j:slf4j-api:1.7.32'
testImplementation 'org.slf4j:slf4j-log4j12:1.7.32'
implementation 'log4j:log4j:1.2.17'

Gradle找不到依赖项

4 个答案: