springboot启动嵌入式tomcat报错找不到jar包，关键字：FileNotFoundException，derbyLocale_cs.jar，StandardJarScanner.scan

柔情只为你懂 2021-06-24 15:59 354阅读 0赞

异常：

java.io.FileNotFoundException: /Users/lanhuajian/.m2/repository/org/apache/derby/derby/10.13.1.1/derbyLocale_cs.jar (No such file or directory)
        at java.util.zip.ZipFile.open(Native Method) ~[?:1.8.0_152]
        at java.util.zip.ZipFile.<init>(ZipFile.java:225) ~[?:1.8.0_152]
        at java.util.zip.ZipFile.<init>(ZipFile.java:155) ~[?:1.8.0_152]
        at java.util.jar.JarFile.<init>(JarFile.java:166) ~[?:1.8.0_152]
        at java.util.jar.JarFile.<init>(JarFile.java:130) ~[?:1.8.0_152]
        at org.apache.tomcat.util.scan.JarFileUrlJar.<init>(JarFileUrlJar.java:60) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.tomcat.util.scan.JarFactory.newInstance(JarFactory.java:49) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.tomcat.util.scan.StandardJarScanner.process(StandardJarScanner.java:338) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.tomcat.util.scan.StandardJarScanner.scan(StandardJarScanner.java:288) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.jasper.servlet.TldScanner.scanJars(TldScanner.java:262) [tomcat-embed-jasper-8.5.23.jar:?]
        at org.apache.jasper.servlet.TldScanner.scan(TldScanner.java:104) [tomcat-embed-jasper-8.5.23.jar:?]
        at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:101) [tomcat-embed-jasper-8.5.23.jar:?]
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5196) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1419) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1409) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266) [?:1.8.0_152]
        at java.util.concurrent.FutureTask.run(FutureTask.java) [?:1.8.0_152]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_152]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_152]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_152]

springboot集成hadoop等组件后会报这个错，一般和hadoop集成需要把老版本的sevlet、jsp、tomcat依赖去掉，但是我去掉之后还是存在。  
所以我跟踪了springboot初始化tomcat的代码，发现在`TomcatEmbeddedServletContainerFactory#prepareContext()`有个`tldSkipPatterns`的东西， 就心想这个是不是会告诉tomcat不要扫描这些jar包呢？试了一下，真的可以！

因此可以得出如下解决方案，在初始化`TomcatEmbeddedServletContainerFactory`后，在后置bean处理器中给它加上tldSkipPatterns即可

import org.springframework.beans.BeansException;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.beans.factory.config.BeanPostProcessor;
    import org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    import java.util.Arrays;
    import java.util.List;
    
    import static java.util.stream.Collectors.toList;
    
    @Configuration
    public class TomcatContainerConfig {
        @Value("${tldSkipPatterns}")
        private String[] tldSkipPatterns;
    
        @Bean
        public BeanPostProcessor TomcatContainerPostProcessor() {
            List<String> notEmptyTldSkipPatterns = Arrays.stream(tldSkipPatterns)
                .filter(tldSkipPattern -> !tldSkipPattern.trim().isEmpty())
                .collect(toList());
    
    
            return new BeanPostProcessor() {
                @Override
                public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
                    return bean;
                }
    
                @Override
                public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
                    if (beanName.equals("tomcatEmbeddedServletContainerFactory") &&
                            bean instanceof TomcatEmbeddedServletContainerFactory) {
                        TomcatEmbeddedServletContainerFactory factory = (TomcatEmbeddedServletContainerFactory) bean;
                        if (!notEmptyTldSkipPatterns.isEmpty()) {
                            factory.addTldSkipPatterns(notEmptyTldSkipPatterns.toArray(new String[0]));
                        }
                    }
                    return bean;
                }
            };
        };
    }

增加下面的配置到 `application.properties`:

tldSkipPatterns=derbyLocale_*.jar,jaxb-api.jar,jsr173_1.0_api.jar,jaxb1-impl.jar,activation.jar