java - 运行 jar 时项目抛出 IOException(未找到文件)

Question

我使用 Eclipse 用 java 创建了一个项目。

这是项目结构:

当我在 Eclipse 中将项目作为 java 应用程序运行时，它运行得很好。

现在，我需要将其导出为 jar。因此，我使用此链接上的第三个答案中描述的方法创建了 jar(由 Fever 回答):

Failing to run jar file from command line: “no main manifest attribute”

这是 jar tf EventLogger.jar 的输出:

META-INF/MANIFEST.MF
com/
com/project/
com/project/eventLogger/
com/project/eventLogger/KafkaConsumerGroup.class
com/project/eventLogger/KafkaProducer.class
com/project/eventLogger/ConsumeConfig.class
com/project/eventLogger/ConsumerThread.class
com/project/eventLogger/Formatter.class
com/project/eventLogger/Execute.class
com/project/eventLogger/Config.class
com/project/eventLogger/package-info.class
com/project/eventLogger/ProdConfig.class
com/project/eventLogger/FormatConfig.class
resources/
resources/Config.properties
resources/ConsumerConfig.properties
resources/FormatterConfig.properties
resources/ProducerConfig.properties
resources/log4j.properties

这是 list 文件:

Manifest-Version: 1.0
Built-By: vishrant
Class-Path: lib/json-simple-1.1.1.jar lib/junit-4.10.jar lib/hamcrest-
 core-1.1.jar lib/kafka_2.9.2-0.8.2.2.jar lib/jopt-simple-3.2.jar lib/
 kafka-clients-0.8.2.2.jar lib/log4j-1.2.16.jar lib/lz4-1.2.0.jar lib/
 metrics-core-2.2.0.jar lib/slf4j-api-1.7.6.jar lib/snappy-java-1.1.1.
 7.jar lib/slf4j-log4j12-1.6.1.jar lib/zkclient-0.3.jar lib/zookeeper-
 3.4.6.jar lib/jline-0.9.94.jar lib/netty-3.7.0.Final.jar lib/scala-li
 brary-2.9.2-RC3.jar
Build-Jdk: 1.8.0_74
Created-By: Maven Integration for Eclipse
Main-Class: com.project.eventLogger.Execute

并且，这是一个异常(exception):

java.io.FileNotFoundException: ConsumerConfig.properties (No such file or directory)
    at java.io.FileInputStream.open0(Native Method)
    at java.io.FileInputStream.open(FileInputStream.java:195)
    at java.io.FileInputStream.<init>(FileInputStream.java:138)
    at java.io.FileInputStream.<init>(FileInputStream.java:93)
    at com.project.eventLogger.ConsumeConfig.loadPropertiesFile(ConsumeConfig.java:34)
    at com.project.eventLogger.ConsumeConfig.<clinit>(ConsumeConfig.java:42)
    at com.project.eventLogger.Execute.main(Execute.java:18)
Exception in thread "main" java.lang.ExceptionInInitializerError
    at com.project.eventLogger.Execute.main(Execute.java:18)
Caused by: java.lang.NullPointerException
    at com.project.eventLogger.ConsumeConfig.<clinit>(ConsumeConfig.java:47)
    ... 1 more

看到异常，很明显它无法加载在 ConsumeConfig.java 中完成的 ConsumerConfig.properties。

这里是ConsumeConfig.java:

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Properties;

/**
 * @author vishrant
 *
 */
public class ConsumeConfig {

    public static String zookeeper;
    public static String balance;
    public static String bootstrap_servers;
    public static String zk_session_to;
    public static String zk_sync;
    public static String auto_commit;
    public static String[] topics;
    private static String kafka_bin;
    private static final String PROPERTIES_FILE_PATH = "src/main/resources/ConsumerConfig.properties";

    private static Properties loadPropertiesFile() throws IOException {
        Properties properties = new Properties();
        InputStream in = new FileInputStream(PROPERTIES_FILE_PATH);
        properties.load(in);
        return properties;
    }

    static {
        Properties property = null;
        try {
            property = loadPropertiesFile();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        zookeeper = property.getProperty("ZOOKEEPER");
        balance = property.getProperty("BALANCE");
        bootstrap_servers = property.getProperty("BOOTSTRAP_SERVERS");
        zk_session_to = property.getProperty("ZK_SESSION_TO");
        zk_sync = property.getProperty("ZK_SYNC_TIME");
        auto_commit = property.getProperty("AUTO_COMMIT_INTERVAL");
        topics = property.getProperty("CONSUMER_TOPICS").split(",");
        kafka_bin = property.getProperty("KAFKA_BIN_PATH");
    }
}

有人可以告诉我问题是什么以及如何解决吗？

在 Eclipse 本身中运行时运行得非常好。

编辑1:

现在，异常(exception)是:

Exception in thread "main" java.lang.ExceptionInInitializerError
    at com.project.eventLogger.Execute.main(Execute.java:18)
Caused by: java.lang.NullPointerException
    at java.util.Properties$LineReader.readLine(Properties.java:434)
    at java.util.Properties.load0(Properties.java:353)
    at java.util.Properties.load(Properties.java:341)
    at com.project.eventLogger.ConsumeConfig.loadPropertiesFile(ConsumeConfig.java:35)
    at com.project.eventLogger.ConsumeConfig.<clinit>       (ConsumeConfig.java:42)
    ... 1 more

第 35 行:

props.load(resourceStream);

这是现在的代码:

private static final String PROPERTIES_FILE_PATH = "ConsumerConfig.properties";

private static Properties loadPropertiesFile() throws IOException {
    ClassLoader loader = Thread.currentThread().getContextClassLoader();
    Properties props = new Properties();
    InputStream resourceStream = loader.getResourceAsStream(PROPERTIES_FILE_PATH);
    props.load(resourceStream);
    return props;
}

Answer 1

我认为原因如下:

• 无法为 Maven 项目正确创建 jar 文件，因为目录 resources 通常不会按原样复制到 target 目录，即，而不是 <

resources/Config.properties

它应该看起来没有资源目录:

Config.properties

直接在jar文件的根目录下。

• 第二点是您在代码中使用以下内容

private static final String PROPERTIES_FILE_PATH = "src/main/resources/ConsumerConfig.properties";

在您的 IDE(本例中为 Eclipse)之外不会看到此路径，因为 src/main/resources 不应存在于 jar 文件中，正如您在 jar 文件列表中看到的那样.

• 最后一点是，您应该使用类加载器的 getResourceAsStream()，因为 Vikrant Kashyap 已经指出了。