Java程序在Netbeans中运行得很好，但是从构建的JAR中运行时就不工作了

Question

我现在是java的一个新手，我所要做的就是为Minecraft服务器添加MySQL日志到这个java代理。

当程序在NetBeans中运行时，程序运行得非常好，没有任何错误。但是，当构建一个jar并从jar中运行程序时，当登录到Minecraft服务器时，会抛出此错误:

SQLNestedException错误:不能创建类'com.mysql.jdbc的JDBC驱动程序。驱动程序'用于连接URL 'jdbc:mysql://localhost:3306/userips' @ org.apache.commons.dbcp.BasicDataSource:1452

基本上它应该做的是记录用户的IP，用户名，时间和登录日期。

我使用Netbeans IDE 7.2.1，并使用Maven构建jar来处理所有依赖项。

我已经使用maven将commons-dbcp-1.4.jar, mysql-connector-java-5.1.22.jar和commons-pool-1.5.4.jar导入到我的Dependencies中，它们位于jar文件中。

下面是建立连接的类:

import java.sql.Connection;
import java.sql.SQLException;
import org.apache.commons.dbcp.BasicDataSource;

public final class ConnectionPooler {
    public static final Configuration config = new Configuration();

    private static final BasicDataSource dataSource = new BasicDataSource();
    static {
        config.load();
        dataSource.setDriverClassName("com.mysql.jdbc.Driver");
        dataSource.setUrl(config.sql_url);
        dataSource.setUsername(config.sql_user);
        dataSource.setPassword(config.sql_pass);
        dataSource.setInitialSize(5);
        dataSource.setMaxActive(30);
    }
    public static Connection getConnection() throws SQLException {
        return dataSource.getConnection();
    } 
}

下面是执行mysql查询的类:

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;
public class IPLogger {

public boolean logip(String player, String ipp) throws SQLException {
    Connection connection = null;
    PreparedStatement statement = null;
    ResultSet resultSet = null;

    Calendar now = Calendar.getInstance();
    TimeZone timeZone1 = now.getTimeZone();
    String timeZone = timeZone1.getDisplayName();
    DateFormat dateFormat = new SimpleDateFormat("MM/dd/yyyy");
    DateFormat timeFormat = new SimpleDateFormat("HH:mm:ss");
    Date date1 = new Date();
    Date date2 = new Date();
    String date;
    String time;
    date = dateFormat.format(date1);
    time = timeFormat.format(date2);

    String SQL_EXIST = "INSERT INTO `proxyips` (`username`, `ip`,`date`,`time`) VALUES ('"+player+"', '"+ipp+"','"+date+"','"+time+" "+timeZone+"')";
    try{
        connection = ConnectionPooler.getConnection();
        statement = connection.prepareStatement(SQL_EXIST);
        statement.executeUpdate();
    } finally {
        if (resultSet != null) {
            try { resultSet.close(); } catch (SQLException ignore) {ignore.printStackTrace(); }
        }
        if (statement != null) {
            try { statement.close(); } catch (SQLException ignore) {ignore.printStackTrace(); }
        }
        if (connection != null) {
            try { connection.close(); } catch (SQLException ignore) {ignore.printStackTrace(); }
        }
    }       
    return true;
}
}

下面是pom.xml，以防我在构建过程中出现错误或类似的情况:

<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>net.md-5</groupId>
    <artifactId>BungeeCordKC</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>BungeeCordKC</name>
    <url>http://maven.apache.org</url>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                  <showDeprecation>false</showDeprecation>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>2.0</version>
                <configuration>
                    <filters>
                        <filter>
                            <artifact>*:*</artifact>
                            <excludes>
                                <exclude>**/*.java</exclude>
                                <exclude>**/*.properties</exclude>
                                <exclude>**/*.SF</exclude>
                                <exclude>**/*.DSA</exclude>
                            </excludes>
                        </filter>
                    </filters>
                </configuration>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>2.4</version>
                <configuration>
                    <archive>
                        <manifestEntries>
                            <Main-Class>${main.class}</Main-Class>
                            <Implementation-Version>${describe}</Implementation-Version>
                        </manifestEntries>
                    </archive>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <build.number>unknown</build.number>
        <main.class>net.md_5.bungee.BungeeCord</main.class>
    </properties>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.yaml</groupId>
            <artifactId>snakeyaml</artifactId>
            <version>1.11</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>0.11.4</version>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>13.0.1</version>
        </dependency>
        <dependency>
            <groupId>com.google.code.findbugs</groupId>
            <artifactId>annotations</artifactId>
            <version>2.0.1</version>
        </dependency>
        <dependency>
            <groupId>org.bouncycastle</groupId>
            <artifactId>bcprov-ext-jdk15on</artifactId>
            <version>1.47</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.22</version>
            <type>jar</type>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>1.4</version>
        </dependency>
        <dependency>
            <artifactId>commons-pool</artifactId>
            <groupId>commons-pool</groupId>
            <type>jar</type>
            <version>1.5.4</version>
        </dependency>
    </dependencies>
</project>

如果有人知道什么是错的，或者如果你对我如何设置我的环境有任何问题，请告诉我。

编辑:当我将catch语句添加到try块中时，这里是完整的堆栈跟踪。

org.apache.commons.dbcp.SQLNestedException: Cannot create JDBC driver of class '
com.mysql.jdbc.Driver' for connect URL 'jdbc:mysql://localhost.com:3306/use
rips'
        at org.apache.commons.dbcp.BasicDataSource.createConnectionFactory(Basic
DataSource.java:1452)
        at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSou
rce.java:1371)
        at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource
.java:1044)
        at net.md_5.bungee.ConnectionPooler.getConnection(ConnectionPooler.java:
30)
        at net.md_5.bungee.IPLogger.logip(IPLogger.java:44)
        at net.md_5.bungee.InitialHandler.run(InitialHandler.java:77)
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
        at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
        at java.util.concurrent.FutureTask.run(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ExceptionInInitializerError
        at com.mysql.jdbc.Util.stackTraceToString(Util.java:355)
        at com.mysql.jdbc.Util.<clinit>(Util.java:120)
        at com.mysql.jdbc.NonRegisteringDriver.parseURL(NonRegisteringDriver.jav
a:764)
        at com.mysql.jdbc.NonRegisteringDriver.acceptsURL(NonRegisteringDriver.j
ava:265)
        at java.sql.DriverManager.getDriver(Unknown Source)
        at org.apache.commons.dbcp.BasicDataSource.createConnectionFactory(Basic
DataSource.java:1437)
        ... 11 more
Caused by: java.lang.RuntimeException: Can't load resource bundle due to underly
ing exception java.util.MissingResourceException: Can't find bundle for base nam
e com.mysql.jdbc.LocalizedErrorMessages, locale en_US
        at com.mysql.jdbc.Messages.<clinit>(Messages.java:61)
        ... 17 more
Caused by: java.util.MissingResourceException: Can't find bundle for base name c
om.mysql.jdbc.LocalizedErrorMessages, locale en_US
        at java.util.ResourceBundle.throwMissingResourceException(Unknown Source
)
        at java.util.ResourceBundle.getBundleImpl(Unknown Source)
        at java.util.ResourceBundle.getBundle(Unknown Source)
        at com.mysql.jdbc.Messages.<clinit>(Messages.java:59)
        ... 17 more

Answer 1

出现错误的原因是在使用maven-shade构建JAR时排除了.properties文件。我强烈建议你不要构建大的jar，而只是简单地使用类路径机制，并将驱动程序等保存在自己的jar文件中。

这是由堆栈跟踪的以下部分演示的:

Caused by: java.lang.RuntimeException: Can't load resource bundle due to underly
ing exception java.util.MissingResourceException: Can't find bundle for base nam
e com.mysql.jdbc.LocalizedErrorMessages, locale en_US
        at com.mysql.jdbc.Messages.<clinit>(Messages.java:61)

资源包也是.properties。

所以要解决这个问题，我的第一个建议是不要建立一个大罐子，否则，你需要通过从

中删除<exclude>**/*.properties</exclude>来改变maven-shade排除过滤器:

<filters>
    <filter>
        <artifact>*:*</artifact>
        <excludes>
            <exclude>**/*.java</exclude>
            <exclude>**/*.properties</exclude>
            <exclude>**/*.SF</exclude>
            <exclude>**/*.DSA</exclude>
        </excludes>
    </filter>
</filters>

它在IDE中工作的原因是它使用使用maven下载的实际JAR文件。