导入了mysql驱动包 按老师说的打了一次，琢磨好久 还是报错，求救

Question

com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: ** BEGIN NESTED EXCEPTION ** com.mysql.jdbc.CommunicationsExceptionMESSAGE: Communications link failure due to underlying exception: ** BEGIN NESTED EXCEPTION ** java.io.EOFExceptionMESSAGE: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.STACKTRACE:java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost. at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1997) at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2411) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2916) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:885) at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1300) at com.mysql.jdbc.Connection.createNewIO(Connection.java:2775) at com.mysql.jdbc.Connection.<init>(Connection.java:1555) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285) at java.sql.DriverManager.getConnection(DriverManager.java:571) at java.sql.DriverManager.getConnection(DriverManager.java:215) at DButil.DButil.main(DButil.java:20)** END NESTED EXCEPTION **Last packet sent to the server was 7 ms ago.STACKTRACE:com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: ** BEGIN NESTED EXCEPTION ** java.io.EOFExceptionMESSAGE: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.STACKTRACE:java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost. at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1997) at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2411) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2916) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:885) at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1300) at com.mysql.jdbc.Connection.createNewIO(Connection.java:2775) at com.mysql.jdbc.Connection.<init>(Connection.java:1555) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285) at java.sql.DriverManager.getConnection(DriverManager.java:571) at java.sql.DriverManager.getConnection(DriverManager.java:215) at DButil.DButil.main(DButil.java:20)** END NESTED EXCEPTION **Last packet sent to the server was 7 ms ago. at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2622) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2916) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:885) at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1300) at com.mysql.jdbc.Connection.createNewIO(Connection.java:2775) at com.mysql.jdbc.Connection.<init>(Connection.java:1555) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285) at java.sql.DriverManager.getConnection(DriverManager.java:571) at java.sql.DriverManager.getConnection(DriverManager.java:215) at DButil.DButil.main(DButil.java:20)** END NESTED EXCEPTION **Last packet sent to the server was 7 ms ago. at com.mysql.jdbc.Connection.createNewIO(Connection.java:2847) at com.mysql.jdbc.Connection.<init>(Connection.java:1555) at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285) at java.sql.DriverManager.getConnection(DriverManager.java:571) at java.sql.DriverManager.getConnection(DriverManager.java:215) at DButil.DButil.main(DButil.java:20)

Answer 1

你的URL后面多了个?号