关于下载的问题

httpServletResponse.reset();
httpServletResponse.setHeader("Content-Disposition","attachment;filename="+filename);
httpServletResponse.getOutputStream().print(ss);
这是我做的下载,SS为从文件中读出来的字符串,当文件大小为20KB左右的时候下载能正常完成,可当文件大小超过100KB时SS能成功获得可下载就会出错,请问为什么呢??
这是报的异常:
ClientAbortException:  java.net.SocketException: Connection reset by peer: socket write error
at org.apache.coyote.tomcat4.OutputBuffer.realWriteBytes(OutputBuffer.java:367)
at org.apache.tomcat.util.buf.ByteChunk.append(ByteChunk.java:294)
at org.apache.tomcat.util.buf.IntermediateOutputStream.write(C2BConverter.java:230)
at sun.nio.cs.StreamEncoder$CharsetSE.writeBytes(Unknown Source)
at sun.nio.cs.StreamEncoder$CharsetSE.implFlushBuffer(Unknown Source)
at sun.nio.cs.StreamEncoder$CharsetSE.implFlush(Unknown Source)
at sun.nio.cs.StreamEncoder.flush(Unknown Source)
at java.io.OutputStreamWriter.flush(Unknown Source)
at org.apache.tomcat.util.buf.WriteConvertor.flush(C2BConverter.java:179)
at org.apache.tomcat.util.buf.C2BConverter.flushBuffer(C2BConverter.java:122)
at org.apache.coyote.tomcat4.OutputBuffer.realWriteChars(OutputBuffer.java:564)
at org.apache.tomcat.util.buf.CharChunk.flushBuffer(CharChunk.java:435)
at org.apache.tomcat.util.buf.CharChunk.append(CharChunk.java:366)
at org.apache.coyote.tomcat4.OutputBuffer.write(OutputBuffer.java:510)
at org.apache.coyote.tomcat4.OutputBuffer.write(OutputBuffer.java:524)
at org.apache.coyote.tomcat4.CoyoteOutputStream.print(CoyoteOutputStream.java:88)
at ts.LogDownload.doPost(LogDownload.java:53)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:716)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:809)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:200)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:146)
at tyco.ccure.util.CharacterFilter.MyFilter.doFilter(MyFilter.java:31)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:146)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:209)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:596)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:433)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:948)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:144)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:596)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:433)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:948)
at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2358)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:133)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:596)
at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:118)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:594)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:116)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:594)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:433)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:948)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:127)
at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:596)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:433)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:948)
at org.apache.coyote.tomcat4.CoyoteAdapter.service(CoyoteAdapter.java:152)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
at java.lang.Thread.run(Unknown Source)