Oracle驱动程序可能不在使用任务“ gradle jar”的类路径中

Question

我用Java编写了一个简单的程序，该程序打开与oracle数据库的连接，然后关闭连接。

我将gradle设置为香草项目。这是我的build.gradle文件：

plugins {
    id 'java'
    id 'application'
    id 'maven'
}

repositories {
    jcenter()
    mavenLocal()
}

dependencies {
    implementation 'com.google.guava:guava:26.0-jre'
    implementation 'com.oracle:ojdbc8:19.3'
    testImplementation 'junit:junit:4.12'
}

// Define the main class for the application
mainClassName = 'lab2.jdbc.App'

jar {
    manifest {
        attributes(
            'Class-Path': configurations.compile.collect { it.getName() }.join(' '),
            'Main-Class': 'lab2.jdbc.App'
        )
    }
}

这是我的主班：

package lab2.jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;

public class App {

    public static void main(String[] args) {
        Properties props = new Properties();
        props.put("user", "user");
        props.put("password", "password");
        try {
            Connection connection = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:XE", props);
            System.out.println("Successfully connected!");
            try {
                connection.close();
                System.out.println("Successfully disconnected");
            } catch (SQLException e) {
                System.out.println("Failed to disconnect: " + e);
            }
        } catch (SQLException e) {
            System.out.println("Failed to connect: " + e);
        }
    }
}

[当我使用任务run运行项目时，它运行正常：

> Task :run
Successfully connected!
Successfully disconnected

BUILD SUCCESSFUL in 6s
2 actionable tasks: 2 executed

但是当我尝试运行jar时，它不起作用：

./gradlew jar
java -jar build/libs/lab2-jdbc.jar
Failed to connect: java.sql.SQLException: No suitable driver found for jdbc:oracle:thin:@localhost:1521:XE

怎么了？

Answer 1

build.gradle文件存在两个问题：

1）Oracle JDBC依赖项应为：

implementation 'com.oracle.ojdbc:ojdbc8:19.3.0.0'

2）您不包括创建胖罐子的类路径依赖项。为此，您需要更改以下内容：

    jar {
        manifest {
            attributes(
                    'Main-Class': 'lab2.jdbc.App'
            )
        }
        from {
            configurations.compileClasspath.filter { it.exists() }.collect { it.isDirectory() ? it : zipTree(it) }
        }
    }