并发数据库访问提供 IllegalStateException [英] Concurrent database access giving IllegalStateException

问题描述

我正在尝试为一种方法生成一个线程.我收到一个 IllegalStateException(见下文).这个方法是做什么的，它接受一个到数据库的连接和数据库名称，它会从中生成 XML.(这部分有效，我只是想通过一个新线程让它运行得更快，因为我要创建多个 XML 文件.

I am trying to spawn a thread for just 1 method. Im getting an IllegalStateException (see below). What this method does it accept a Connection to a database and the database name, and it will generate XML from it. (That part works I am just trying to make it go faster with a new thread because I have multiple XML files to create.

    Thread table = new Thread(new Runnable() {
    public void run() {
    try {
     System.out.println("starting");
     tableXml(tableConn, dbName);
     System.out.println("ending");
     }
     catch (Exception e) {
      // TODO Auto-generated catch block
        e.printStackTrace();
      }
  }
});

    table.start();

异常:

java.lang.IllegalStateException: Current state = RESET, new state = FLUSHED
    at java.nio.charset.CharsetEncoder.throwIllegalStateException(CharsetEncoder.java:951)
    at java.nio.charset.CharsetEncoder.flush(CharsetEncoder.java:640)
    at java.nio.charset.CharsetEncoder.encode(CharsetEncoder.java:769)
    at com.informix.lang.JavaToIfxType.doConversion(JavaToIfxType.java:841)
    at com.informix.lang.JavaToIfxType.JavaToIfxChar(JavaToIfxType.java:145)
    at com.informix.jdbc.IfxVarChar.toString(IfxVarChar.java:247)
    at com.informix.jdbc.IfxResultSet.getString(IfxResultSet.java:742)
    at com.informix.jdbc.IfxResultSet.getString(IfxResultSet.java:785)
    at org.apache.commons.dbcp.DelegatingResultSet.getString(DelegatingResultSet.java:225)
    at com.test.ex.ExportTask$1.run(ExportTask.java:151)
    at java.lang.Thread.run(Thread.java:662)

导致异常的代码行是 resultSet.executeQuery();

所以问题是:我做错了什么?

So the question is: what am I doing wrong?

感谢您的帮助，如果您需要信息，请告诉我

Thanks for your help, let me know if you need information

推荐答案

问题似乎是因为您的代码不是线程安全的.尝试为产生的每个新线程提供自己的连接，而不是在应用程序中的所有线程之间共享单个连接的引用.

It seems that the problem is because your code is not thread safe. Try giving each new thread that is spawned its own connection instead of sharing a reference of a single connection between all threads in your application.

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