1、Jdbc内存泄露问题
1 严重: The web application [] registered the JDBC driver [com.alibaba.druid.proxy.DruidDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered. 2 3 6月 02, 2018 2:42:06 下午 org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc 4 5 严重: The web application [] registered the JDBC driver [com.alibaba.druid.mock.MockDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered. 6 7 6月 02, 2018 2:42:06 下午 org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc 8 9 严重: The web application [] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered. 10 11 6月 02, 2018 2:42:06 下午 org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc 12 13 严重: The web application [] registered the JDBC driver [com.mysql.fabric.jdbc.FabricMySQLDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered. 14 15 6月 02, 2018 2:42:06 下午 org.apache.catalina.loader.WebappClassLoader clearReferencesThreads 16 17 严重: The web application [] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak. 18 19 6月 02, 2018 2:42:06 下午 org.apache.coyote.AbstractProtocol start
网上查询之后知道得到错误原因是DruidDriver内存泄漏，
要避免这个信息，应用或框架应该自己来保证在销毁时将JDBC Driver反注册掉。
我想DruidDriver应该有解决办法，于是改变关键词继续百度，发现最新版本的DruidDriver已经修复了这个bug，于是将版本更新为1.1.9
更新之后还是失败，
最后找到原因是pageHelper和逆向工程冲突使得没有办法销毁jdbc
2、web层接收数据错误
1 com.alibaba.dubbo.remoting.RemotingException: Failed to send response: Response [id=2, version=2.0.0, status=20, event=false, error=null, result=RpcResult [[email protected]42a0, exception=null]], cause: java.lang.IllegalStateException: Serialized class cn.thyonline.taotao.common.pojo.EasyUIDataGridResult must implement java.io.Serializable 2 3 java.lang.IllegalStateException: Serialized class cn.thyonline.taotao.common.pojo.EasyUIDataGridResult must implement java.io.Serializable 4 5 at com.alibaba.com.caucho.hessian.io.SerializerFactory.getDefaultSerializer(SerializerFactory.java:261) 6 7 at com.alibaba.com.caucho.hessian.io.SerializerFactory.getSerializer(SerializerFactory.java:233) 8 9 at com.alibaba.com.caucho.hessian.io.Hessian2Output.writeObject(Hessian2Output.java:406) 10 11 at com.alibaba.dubbo.common.serialize.support.hessian.Hessian2ObjectOutput.writeObject(Hessian2ObjectOutput.java:92) 12 13 at com.alibaba.dubbo.rpc.protocol.dubbo.DubboCodec.encodeResponseData(DubboCodec.java:200) 14 15 at com.alibaba.dubbo.remoting.exchange.codec.ExchangeCodec.encodeResponse(ExchangeCodec.java:276) 16 17 at com.alibaba.dubbo.remoting.exchange.codec.ExchangeCodec.encode(ExchangeCodec.java:77) 18 19 at com.alibaba.dubbo.rpc.protocol.dubbo.DubboCountCodec.encode(DubboCountCodec.java:39) 20 21 at com.alibaba.dubbo.remoting.transport.netty.NettyCodecAdapter$InternalEncoder.encode(NettyCodecAdapter.java:81) 22 23 at org.jboss.netty.handler.codec.oneone.OneToOneEncoder.doEncode(OneToOneEncoder.java:66) 24 25 at org.jboss.netty.handler.codec.oneone.OneToOneEncoder.handleDownstream(OneToOneEncoder.java:59) 26 27 at org.jboss.netty.channel.DefaultChannelPipeline.sendDownstream(DefaultChannelPipeline.java:591) 28 29 at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendDownstream(DefaultChannelPipeline.java:784) 30 31 at org.jboss.netty.channel.SimpleChannelHandler.writeRequested(SimpleChannelHandler.java:292) 32 33 at com.alibaba.dubbo.remoting.transport.netty.NettyHandler.writeRequested(NettyHandler.java:99) 34 35 at org.jboss.netty.channel.SimpleChannelHandler.handleDownstream(SimpleChannelHandler.java:254) 36 37 at org.jboss.netty.channel.DefaultChannelPipeline.sendDownstream(DefaultChannelPipeline.java:591) 38 39 at org.jboss.netty.channel.DefaultChannelPipeline.sendDownstream(DefaultChannelPipeline.java:582) 40 41 at org.jboss.netty.channel.Channels.write(Channels.java:704) 42 43 at org.jboss.netty.channel.Channels.write(Channels.java:671) 44 45 at org.jboss.netty.channel.AbstractChannel.write(AbstractChannel.java:248) 46 47 at com.alibaba.dubbo.remoting.transport.netty.NettyChannel.send(NettyChannel.java:98) 48 49 at com.alibaba.dubbo.remoting.transport.AbstractPeer.send(AbstractPeer.java:51) 50 51 at com.alibaba.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.received(HeaderExchangeHandler.java:171) 52 53 at com.alibaba.dubbo.remoting.transport.DecodeHandler.received(DecodeHandler.java:52) 54 55 at com.alibaba.dubbo.remoting.transport.dispatcher.ChannelEventRunnable.run(ChannelEventRunnable.java:82) 56 57 at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1135) 58 59 at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) 60 61 at java.base/java.lang.Thread.run(Thread.java:844)
java.io.Serializable可以发现因为在dubbo中传递的数据类型为EasyUIDataGridResult不是字节流形式传递，需要序列化操作
序列化是什么：
序列化就是将一个对象的状态（各个属性量）保存起来，然后在适当的时候再获得。
序列化分为两大部分：序列化和反序列化。序列化是这个过程的第一部分，将数据分解成字节流，以便存储在文件中或在网络上传输。反序列化就是打开字节流并重构对象。对象序列化不仅要将基本数据类型转换成字节表示，有时还要恢复数据。恢复数据要求有恢复数据的对象实例
3、pageHelper出错
1 警告: Hessian/Burlap: ‘com.github.pagehelper.Page‘ is an unknown class in WebappClassLoader 2 3 context: 4 5 delegate: false 6 7 repositories: 8 9 /WEB-INF/classes/ 10 11 ----------> Parent Classloader: 12 13 ClassRealm[plugin>org.apache.tomcat.maven:tomcat7-maven-plugin:2.2, parent: [email protected]] 14 15 : 16 17 java.lang.ClassNotFoundException: com.github.pagehelper.Page
com.github.pagehelper.Page是一个没有找到的类。Google之后发现原因是
service层有pageHelper的依赖，但是web层没有，所以传递过来的pageHelper的数据没有找对对应的类，解决办法就是在web层中加入pageHelper的依赖
4、页面没有显示查询列表，但是后端数据测试知道已经传递到前端
1 Uncaught TypeError: Cannot read property ‘length‘ of undefined 2 3 at Object.render (jquery.easyui.min.js:9903) 4 5 at _5f6 (jquery.easyui.min.js:8837) 6 7 at jquery.easyui.min.js:9422 8 9 at Object.success (jquery.easyui.min.js:10128) 10 11 at j (jquery.min.js:2) 12 13 at Object.fireWith [as resolveWith] (jquery.min.js:2) 14 15 at x (jquery.min.js:4) 16 17 at XMLHttpRequest.b (jquery.min.js:4)
查看网页的响应会发现数据已经在网页端接收到
所以可以推断整个架构没有问题。但是没能在页面正常显示。查看静态页面的写好的数据：
1 {"total":28,"rows":[
2
3 {"productid":"FI-SW-01","unitcost":10.00,"status":"P","listprice":36.50,"attr1":"Large","itemid":"EST-1"},
4
5 {"productid":"K9-DL-01","unitcost":12.00,"status":"P","listprice":18.50,"attr1":"Spotted Adult Female","itemid":"EST-10"},
6
7 {"productid":"RP-SN-01","unitcost":12.00,"status":"P","listprice":28.50,"attr1":"Venomless","itemid":"EST-11"},
8
9 {"productid":"RP-SN-01","unitcost":12.00,"status":"P","listprice":26.50,"attr1":"Rattleless","itemid":"EST-12"},
10
11 {"productid":"RP-LI-02","unitcost":12.00,"status":"P","listprice":35.50,"attr1":"Green Adult","itemid":"EST-13"},
12
13 {"productid":"FL-DSH-01","unitcost":12.00,"status":"P","listprice":158.50,"attr1":"Tailless","itemid":"EST-14"},
14
15 {"productid":"FL-DSH-01","unitcost":12.00,"status":"P","listprice":83.50,"attr1":"With tail","itemid":"EST-15"},
16
17 {"productid":"FL-DLH-02","unitcost":12.00,"status":"P","listprice":63.50,"attr1":"Adult Female","itemid":"EST-16"},
18
19 {"productid":"FL-DLH-02","unitcost":12.00,"status":"P","listprice":89.50,"attr1":"Adult Male","itemid":"EST-17"},
20
21 {"productid":"AV-CB-01","unitcost":92.00,"status":"P","listprice":63.50,"attr1":"Adult Male","itemid":"EST-18"}
22
23 ],"footer":[
24
25 {"unitcost":19.80,"listprice":60.40,"productid":"Average:"},
26
27 {"unitcost":198.00,"listprice":604.00,"productid":"Total:"}
28
29 ]}
检查传来数据的名称和json需要的数据的名称可以发现EasyUIDataGridResult里面的参数写成了row然后转成json数据传递。但是在页面需要的数据为rows则不匹配。
于是将EasyUIDataGridResult中的数据名称修改，再次运行则成功显示。
原文地址：https://www.cnblogs.com/thyHome/p/9127772.html
时间： 2024-08-05 13:15:33