运行jar文件

今天药忘吃喽~ 2023-10-17 09:03 94阅读 0赞

> 平时都是在eclipse或者IntelliJ IDEA等IDE中运行java程序。突然有一天，需要将程序打包运行！怎么办呢？今天就给大家分享一下。

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首先，我们看一下示例小程序的整体结构：

![这里写图片描述][20161017112138934]

小程序很简单吧，注意看三个额外的依赖jar包，后面要提及的。

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接下来，简单地看一下代码：

log4j.rootLogger = debug,stdout,D,E
    
    log4j.appender.stdout = org.apache.log4j.ConsoleAppender
    log4j.appender.stdout.Target = System.out
    log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
    log4j.appender.stdout.layout.ConversionPattern = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n
    
    log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
    log4j.appender.D.Append = true
    log4j.appender.D.Threshold = DEBUG 
    log4j.appender.D.layout = org.apache.log4j.PatternLayout
    log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n
    
    log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
    log4j.appender.E.Append = true
    log4j.appender.E.Threshold = ERROR 
    log4j.appender.E.layout = org.apache.log4j.PatternLayout
    log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

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drivername=com.mysql.jdbc.Driver
    dburl=jdbc:mysql://node3.quantumsec.cn:3306/mydatabase?zeroDateTimeBehavior=convertToNull&autoReconnect=true&characterEncoding=UTF-8&characterSetResults=UTF-8
    username=root
    password=hadoop123

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package com.metron.database;
    
    import java.io.IOException;
    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.sql.Statement;
    import java.util.Properties;
    
    public class DBConnection {
        
        public static Connection conn = null;
        public static String driverClass = "";
        public static String dbURL = "";
        public static String dbUser = "";
        public static String dbPwd = "";
    
        static {
            loadProperty();
        }
    
        public static boolean loadProperty() {
            Properties properties = new Properties();
            try {
                properties.load(DBConnection.class.getResourceAsStream("db.properties"));
                driverClass = properties.getProperty("drivername");
                dbURL = properties.getProperty("dburl");
                dbUser = properties.getProperty("username");
                dbPwd = properties.getProperty("password");
            } catch (IOException e) {
                return false;
            }
            return true;
        }
    
        public static void openConn() {
            try {
                Class.forName(driverClass).newInstance();
                conn = DriverManager.getConnection(dbURL, dbUser, dbPwd);
            } catch (InstantiationException | IllegalAccessException | ClassNotFoundException | SQLException e) {
                return;
            }
        }
    
        public static void closeConn() {
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
                conn = null;
            }
        }
    
        public static void closeStatement(Statement stmt) {
            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
                stmt = null;
            }
        }
    
        public static void closeResultSet(ResultSet rs) {
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
                rs = null;
            }
        }
    }

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package com.metron.database;
    
    public class Person {
        
        private String name;
        private int age;
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public int getAge() {
            return age;
        }
    
        public void setAge(int age) {
            this.age = age;
        }
    
        @Override
        public String toString() {
            // TODO Auto-generated method stub
            return "name : " + this.name + " , age : " + this.age;
        }
    
    }

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package com.metron.database;
    
    import java.io.IOException;
    import java.sql.PreparedStatement;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    
    public class MainTest {
    
        private static Logger _LOG = LoggerFactory.getLogger(MainTest.class);
    
        public static void main(String[] args) throws IOException {
    
            Person person = new Person();
    
            if (DBConnection.conn == null) {
                DBConnection.openConn();
            }
    
            _LOG.info("url : " + DBConnection.dbURL);
            _LOG.info("usr : " + DBConnection.dbUser);
            _LOG.info("pwd : " + DBConnection.dbPwd);
    
            try {
                String sql = "select * from person";
                PreparedStatement ps = DBConnection.conn.prepareStatement(sql);
                ResultSet rs = ps.executeQuery();
                while (rs.next()) {
                    person.setName(rs.getString("name"));
                    person.setAge(rs.getInt("age"));
                    _LOG.info(person.toString());
                }
                DBConnection.closeResultSet(rs);
                DBConnection.closeStatement(ps);
                DBConnection.closeConn();
            } catch (SQLException e) {
                e.printStackTrace();
            }
    
    
        }
    
    }

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确定代码没有问题，我们就可以打包了：  
![这里写图片描述][20161017112626786]  
![这里写图片描述][20161017112637973]

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到这里，程序还是不能直接运行的，因为我们的依赖包是没有包含进来。下面添加依赖包。在jar文件里边的META-INF目录下，有一个名为MANIFEST.MF的文件，我们打开它，添加下面一句话：

Class-Path: lib/mysql-connector-java-5.1.37-bin.jar lib/slf4j-api-1.7.7.jar lib/slf4j-simple-1.7.1.jar

![这里写图片描述][20161017113108355]

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好了，依赖包确实配置好了，可是包放在哪里呢？是这样的：我们在刚才的程序包–MysqlConnTestDemo.jar的统计目录下创建一个名为“lib”的文件夹，然后将依赖的jar包放进去就可以了。

![这里写图片描述][20161017113459047]

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接下来，就可以运行程序了。  
![这里写图片描述][20161017113631315]

[20161017112138934]: https://img-blog.csdn.net/20161017112138934
[20161017112626786]: https://img-blog.csdn.net/20161017112626786
[20161017112637973]: https://img-blog.csdn.net/20161017112637973
[20161017113108355]: https://img-blog.csdn.net/20161017113108355
[20161017113459047]: https://img-blog.csdn.net/20161017113459047
[20161017113631315]: https://img-blog.csdn.net/20161017113631315