无法与MySQL建立JDBC连接（使用Java，IntelliJ和Linux）

我在使用以下代码尝试获取数据库连接时遇到问题：

I am having issues trying to get a database connection using the code below:

  try {
        Class.forName("com.mysql.jdbc.Driver");
        Properties p = new Properties();
        p.put("user", user_name);
        p.put("password", password);
        connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1/jsp_test", p);
    } catch (SQLException ex) {
        // handle any errors
        ex.printStackTrace();
        System.out.println("SQLException: " + ex.getMessage());
        System.out.println("SQLState: " + ex.getSQLState());
        System.out.println("VendorError: " + ex.getErrorCode());
        return false;
    } catch (ClassNotFoundException e) {
        e.printStackTrace();  
    }

输出的错误信息是：

/ usr / lib / jvm / java-6-openjdk / bin / java
-Didea.launcher.port = 7532 -Didea.launcher.bin.path = / usr / bin / idea / bin
-Dfile.encoding = UTF-8 -classpath /usr/lib/jvm/java-6-openjdk/jre/lib/jce.jar:/usr/lib/jvm /java-6-openjdk/jre/lib/about.jar:/usr/lib/jvm/java-6-openjdk/jre/lib/resources.jar:/usr/lib/jvm/java-6-openjdk/jre /lib/management-agent.jar:/usr/lib/jvm/java-6-openjdk/jre/lib/jsse.jar:/usr/lib/jvm/java-6-openjdk/jre/lib/charsets.jar ：/usr/lib/jvm/java-6-openjdk/jre/lib/rt.jar：/usr/lib/jvm/java-6-openjdk/jre/lib/ext/localedata.jar：/ usr / lib中/ JVM / JAVA -6-的openjdk / JRE / lib / ext目录/程序（sunjce_provider.jar）：/usr/lib/jvm/java-6-openjdk/jre/lib/ext/sunpkcs11.jar：/ usr / lib中/ JVM / Java的6-openjdk / jre / lib / ext / dnsns.jar：/ home / bedtimes / Java
Projects / db_demo / out / production / db_demo：/ opt / java / jre / lib / ext / mysql-connector-java -5.1.10-bin.jar：/usr/bin/idea/lib/idea_rt.jar com.intellij.rt。 execution.application.AppMain
Main
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException：
通讯链接失败

/usr/lib/jvm/java-6-openjdk/bin/java -Didea.launcher.port=7532 -Didea.launcher.bin.path=/usr/bin/idea/bin -Dfile.encoding=UTF-8 -classpath /usr/lib/jvm/java-6-openjdk/jre/lib/jce.jar:/usr/lib/jvm/java-6-openjdk/jre/lib/about.jar:/usr/lib/jvm/java-6-openjdk/jre/lib/resources.jar:/usr/lib/jvm/java-6-openjdk/jre/lib/management-agent.jar:/usr/lib/jvm/java-6-openjdk/jre/lib/jsse.jar:/usr/lib/jvm/java-6-openjdk/jre/lib/charsets.jar:/usr/lib/jvm/java-6-openjdk/jre/lib/rt.jar:/usr/lib/jvm/java-6-openjdk/jre/lib/ext/localedata.jar:/usr/lib/jvm/java-6-openjdk/jre/lib/ext/sunjce_provider.jar:/usr/lib/jvm/java-6-openjdk/jre/lib/ext/sunpkcs11.jar:/usr/lib/jvm/java-6-openjdk/jre/lib/ext/dnsns.jar:/home/bedtimes/Java Projects/db_demo/out/production/db_demo:/opt/java/jre/lib/ext/mysql-connector-java-5.1.10-bin.jar:/usr/bin/idea/lib/idea_rt.jar com.intellij.rt.execution.application.AppMain Main com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

最后数据包成功发送到
服务器是0毫秒前。
驱动程序没有从服务器收到任何
的数据包。 at
sun.reflect.NativeConstructorAccessorImpl.newInstance0（Native
Method）at
sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructorAccessorImpl.java:57）
at
sun。 reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:45）
at
java.lang.reflect.Constructor.newInstance（Constructor.java:532）
at
com.mysql。 jdbc.Util.handleNewInstance（Util.java:406）
at
com.mysql.jdbc.SQLError.createCommunicationsException（SQLError.java:1074）
at
com.mysql。 jdbc.ConnectionImpl.createNewIO（ConnectionImpl.java:2214）
at
com.mysql.jdbc.ConnectionImpl。（ConnectionImpl.java:781）
at
com.mysql.jdbc .JDBC4Connection。（JDBC4Connection.java:46）
at
sun.reflect.NativeConstructorAccessorImpl.newInstance0（Native
Method）at
sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructorAccessorImpl.java ：57）
at
sun.reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:45）
at
java.lang.reflect.Constructor.newInstance（Constructor.java:532)
at
com.mysql.jdbc.Util.handleNewInstance（Util.java:406）
at
com.mysql.jdbc.ConnectionImpl.getInstance（ConnectionImpl.java:352)
at
com.mysql.jdbc.NonRegisteringDriver.connect（NonRegisteringDriver.java:284）
at
java.sql.DriverManager.getConnection（DriverManager.java:620)
at
java.sql.DriverManager.getConnection（DriverManager.java:169）
at
database.Database.connect（Database.java:80）
at Main.main（Main。 java：13）at
sun.reflect.NativeMethodAccessorImpl.invoke0（Native
Method）at
sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:57）
at
sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）
at
java.lang.reflect.Method.invoke（Method.java:616）
at
com.intellij.rt.execution.application.AppMain.main（AppMain.java:110)
引起：
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException：
通信链接失败

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:532) at com.mysql.jdbc.Util.handleNewInstance(Util.java:406) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2214) at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:781) at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:46) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:532) at com.mysql.jdbc.Util.handleNewInstance(Util.java:406) at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:352) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:284) at java.sql.DriverManager.getConnection(DriverManager.java:620) at java.sql.DriverManager.getConnection(DriverManager.java:169) at database.Database.connect(Database.java:80) at Main.main(Main.java:13) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:616) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:110) Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

最后一个数据包成功发送到
服务器是0毫秒前。
驱动程序没有从服务器收到任何
的数据包。 at
sun.reflect.NativeConstructorAccessorImpl.newInstance0（Native
Method）at
sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructorAccessorImpl.java:57）
at
sun。 reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:45）
at
java.lang.reflect.Constructor.newInstance（Constructor.java:532）
at
com.mysql。 jdbc.Util.handleNewInstance（Util.java:406）
at
com.mysql.jdbc.SQLError.createCommunicationsException（SQLError.java:1074）
at
com.mysql。 jdbc.MysqlIO。（MysqlIO.java:343）
at
com.mysql.jdbc.ConnectionImpl.createNewIO（ConnectionImpl.java:2137）
... 18更多引起：
java.net.ConnectException：连接
在
java.net.PlainSocketImpl.socketConnect（Native
方法）处拒绝
java.net.AbstractPlainSocketImpl.doConnect（AbstractPlainSocketImpl.java） ：310）
at
java.net.AbstractPl ainSocketImpl.connectToAddress（AbstractPlainSocketImpl.java:176）
at
java.net.AbstractPlainSocketImpl.connect（AbstractPlainSocketImpl.java:163）
at
java.net.SocksSocketImpl.connect（ SocksSocketImpl.java:384）
at
java.net.Socket.connect（Socket.java:542）
at
java.net.Socket.connect（Socket.java： 492）
at
java.net.Socket。（Socket.java:389）
at
java.net.Socket。（Socket.java:232）
at
com.mysql.jdbc.StandardSocketFactory.connect（StandardSocketFactory.java:253）
at
com.mysql.jdbc.MysqlIO。（MysqlIO.java:292)
。 .. 19更多SQLException：
通信链接失败

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:532) at com.mysql.jdbc.Util.handleNewInstance(Util.java:406) at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074) at com.mysql.jdbc.MysqlIO.(MysqlIO.java:343) at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2137) ... 18 more Caused by: java.net.ConnectException: Connection refused at java.net.PlainSocketImpl.socketConnect(Native Method) at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:310) at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:176) at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:163) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:384) at java.net.Socket.connect(Socket.java:542) at java.net.Socket.connect(Socket.java:492) at java.net.Socket.(Socket.java:389) at java.net.Socket.(Socket.java:232) at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:253) at com.mysql.jdbc.MysqlIO.(MysqlIO.java:292) ... 19 more SQLException: Communications link failure

服务器成功发送到
的最后一个数据包是0毫秒前。
驱动程序没有从服务器收到任何
的数据包。 SQLState：08S01
VendorError：0

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. SQLState: 08S01 VendorError: 0

完成退出代码0的流程

我确实不知道如何解决此错误消息。数据库存在。用户名和密码存在。我目前没有在数据库中添加任何表格，但我认为这不是问题所在，因为我毕竟只是建立连接...

I've, literally, no idea how to troubleshoot this error message. The database exists. The username and password exists. I've currently not added any tables to the database but I don't think that can be the issue, since I'm only making a connection after all...

如果需要，我可以提供额外的信息。我觉得我已经尝试了很多。有没有人知道如何获得有关失败的方式和原因的更多信息？

I can provide extra information if needs be. I feel like I've tried a lot. Does anybody know any ways of getting further information on how and why it's failing?

感谢您的帮助！ ：）