Question

java+mysql，频繁连接报错

由于数据库里面表的关联性，需要不停连接和释放，数据有1500多条，用java批量插入的，每次插入到980多条时候报错，错误信息如下，期间连接约3000次，要更改配置还是代码问题？我每次开连接都关闭的，都是一开一关对应的

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Last packet sent to the server was 0 ms ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
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:2120)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:723)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
at sun.reflect.GeneratedConstructorAccessor5.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:207)
at com.job.database.ConnDB.getConn(ConnDB.java:39)
at com.job.dept.Major.<init>(Major.java:60)
at com.test.app.BathInsertOthers.main(BathInsertOthers.java:73)
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The driver was unable to create a connection due to an inability to establish the client portion of a socket.

Answer 1

需要程序
插入这么多，不一定每次都创建连接，然后释放连接。
可以只创建一次连接，插入所有数据后，在释放这个唯一的连接。

Answer 2

连接数据库的时候做成静态的语句块,不用每次添加都要去连接数据,去关闭连接

Answer 3

你要改你的SQL 语句，每次允许处理2500条左右