jFreeChart图片不能自动删除的问题

一般情况下，当你的session过期的时候，它是会自动删除的。当然也会出现例外的情况。比如说：忽然关闭服务器等等要是你的程序全部不能自动删除创建的图像的话，那就有点问题了需要修改一点源代码了，重新打包一下就可以了

解决方案 »

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用VML做的.<html xmlns:v="urn:schemas-microsoft-com:vml"><head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<meta name="GENERATOR" content="Microsoft FrontPage 4.0">
<meta name="ProgId" content="FrontPage.Editor.Document">
<title></title>
<style>v\:*{behavior:url(#default#vml)}/*声明v为vml变量*/</style>
</head><body onload="InitVRML();"><script>
//模拟数据
var RecordSetArray=new Array();
//模拟记录条数
var iRecordCount=20;
for(iIndex=0;iIndex<iRecordCount;iIndex++)
{
var UnitArray=new Array();
UnitArray[0]=iIndex;
UnitArray[1]=Math.round(Math.random()*1000);
RecordSetArray[iIndex]=UnitArray;
}
//模拟数据Y轴最大值[范围]
var iRecordMaxX=20;//模拟数据X轴最大值[范围]
var iRecordMaxY=1000;//模拟数据Y轴最大值[范围]
//坐标系统
var iScreenWidth=400;//真实宽度PX
var iScreenHeight=400;//真实高度PX
var iCoordSizeX=4000;//分隔宽度
var iCoordSizeY=4000;//分隔高度
var iCoordSizeStep=200;//坐标轴与边距
var iRectSize=100;//柱状图柱体宽度
var vGroup=null;//VRML区域
function Line(iRecordCount)
{
VRMLID.innerHTML="";
InitVRML();
CoordSize();
CoordSizeLine();
var iFromX=iCoordSizeStep;
var iFromY=0;
for(iIndex=0;iIndex<iRecordCount;iIndex++)
{
var vLine=document.createElement("v:line");
vLine.style.left="0";
vLine.style.top="0";
vLine.from="'"+iFromX+","+iFromY+"'";
iFromX=iCoordSizeStep+Math.round(RecordSetArray[iIndex][0]*(iCoordSizeX-iCoordSizeStep)/iRecordMaxX);
iFromY=Math.round(RecordSetArray[iIndex][1]*(iCoordSizeY-iCoordSizeStep)/iRecordMaxY);
vLine.to="'"+iFromX+","+iFromY+"'";
vLine.strokecolor="#000000";
vLine.strokeweight="1";
vLine.title="模拟数据第"+RecordSetArray[iIndex][0]+"条";
//var vStroke=document.createElement("v:stroke");
//vStroke.EndArrow="Classic";
//vStroke.StartArrow="Oval";
//vLine.appendChild(vStroke);
vGroup.appendChild(vLine);
}
}
function Circle(iRecordCount)
{
VRMLID.innerHTML="";
InitVRML();
var varMax=Math.pow(2,16)*360;
var vTotal=1;
var vStartAngle=0;
var vEndAngle=0;
var vPreAngle=0;
for(kIndex=0;kIndex<iRecordCount;kIndex++)
{
vTotal+=RecordSetArray[kIndex][1];
}
for(iIndex=0;iIndex<iRecordCount;iIndex++)
{
var vShape=document.createElement("v:shape");
vStartAngle+=vPreAngle;
vPreAngle=RecordSetArray[iIndex][1]/vTotal;
         vEndAngle=RecordSetArray[iIndex][1]/vTotal; vShape.style.width=iCoordSizeX-2*iCoordSizeStep;
vShape.style.height=iCoordSizeY-2*iCoordSizeStep;
vShape.style.top=iCoordSizeStep;
vShape.style.left=iCoordSizeStep;
vShape.strokecolor="black";
vShape.fillcolor=RandColor();         vShape.path="M 2000 2000 AE 2000 2000 2000 2000 "+parseInt(varMax*vStartAngle)+" "+parseInt(varMax*vEndAngle)+" xe";
vShape.title="第"+RecordSetArray[iIndex][0]+"块";
vShape._scale=parseInt(360*(vStartAngle+vEndAngle/2));
vGroup.appendChild(vShape);
}
}
function Bar(iRecordCount)
{
VRMLID.innerHTML="";
InitVRML();
CoordSize();
CoordSizeLine();
var iStep=Math.round(iCoordSizeX/iRecordCount);
for(iIndex=1;iIndex<iRecordCount;iIndex++)
{
var iRnd=Math.round(Math.random()*(iCoordSizeY-iCoordSizeStep));
var vRect=document.createElement("v:rect");
vRect.style.left=iStep*iIndex;
vRect.style.top=(iCoordSizeY-iCoordSizeStep)-Math.round(RecordSetArray[iIndex][1]*(iCoordSizeY-iCoordSizeStep)/iRecordMaxY);
vRect.style.width=iRectSize;
vRect.style.height=Math.round(RecordSetArray[iIndex][1]*(iCoordSizeY-iCoordSizeStep)/iRecordMaxY);
vRect.fillColor="#EEEEEE";
vRect.title="模拟数据第"+RecordSetArray[iIndex][0]+"条的Y轴图示";
vGroup.appendChild(vRect);
}
}
function DrawLinesX(iMaxX,Object)
{
var iStep=Math.round(iCoordSizeX/iMaxX);
for(var iIndex=1;iIndex<=iMaxX;iIndex++)
{
var vLine=document.createElement("v:line");
vLine.from=iStep*iIndex+","+(iCoordSizeY-iCoordSizeStep);
vLine.to=iStep*iIndex+","+(iCoordSizeY-Math.round(iCoordSizeStep/2));
var vStroke=document.createElement("v:stroke");
vStroke.endArrow="Diamond";
vStroke.dashStyle="dot";
vLine.appendChild(vStroke);
Object.appendChild(vLine);
}
}
function DrawLinesY(iMaxY,Object)
{
var iStep=Math.round(iCoordSizeY/iMaxY);
for(var iIndex=0;iIndex<iMaxY;iIndex++)
{
var vLine=document.createElement("v:line");
vLine.from=iCoordSizeStep+","+iStep*iIndex;
vLine.to=Math.round(iCoordSizeStep/2)+","+iStep*iIndex;
var vStroke=document.createElement("v:stroke");
vStroke.endArrow="Diamond";
vStroke.dashStyle="dot";
vLine.appendChild(vStroke);
Object.appendChild(vLine);
}
}
function InitVRML()
{
VRMLID.innerHTML="";
vGroup=document.createElement("v:group");
vGroup.style.width=iScreenWidth+"px";
vGroup.style.height=iScreenHeight+"px";
vGroup.coordsize=iCoordSizeX+","+iCoordSizeY;

var vRect=document.createElement("v:rect");
vRect.style.width=iCoordSizeX+"px";
vRect.style.height=iCoordSizeY+"px";
vRect.fillColor="#FFFFFF";
vRect.strokeColor="#000000";
var vShadow=document.createElement("v:shadow");
vShadow.on="true";
vShadow.type="single";
vShadow.color="silver";
vShadow.offset="5pt,5pt";
vRect.appendChild(vShadow);
vGroup.appendChild(vRect); VRMLID.appendChild(vGroup);
}
function CoordSize()
{
var vLineX=document.createElement("v:line");
vLineX.from=iCoordSizeStep+","+iCoordSizeStep;
vLineX.to=iCoordSizeStep+","+(iCoordSizeY-iCoordSizeStep);
var vStrokeX=document.createElement("v:stroke");
vStrokeX.startArrow="classic";
vStrokeX.endArrow="oval";
vStrokeX.dashStyle="single";
vLineX.appendChild(vStrokeX);
vGroup.appendChild(vLineX); var vLineY=document.createElement("v:line");
vLineY.from=iCoordSizeStep+","+(iCoordSizeY-iCoordSizeStep);
vLineY.to=(iCoordSizeX-iCoordSizeStep)+","+(iCoordSizeY-iCoordSizeStep);
var vStrokeY=document.createElement("v:stroke");
vStrokeY.startArrow="oval";
vStrokeY.endArrow="classic";
vStrokeY.dashStyle="single";
vLineY.appendChild(vStrokeY);
vGroup.appendChild(vLineY);
}
function CoordSizeLine()
{
DrawLinesX(RecordSetArray.length,vGroup);
DrawLinesY(RecordSetArray.length,vGroup);
}
function RandColor()
{
return "rgb("+parseInt(Math.random()*255)+","+parseInt(Math.random()*255)+","+parseInt(Math.random()*255)+")";
}
function Zoom(iValue)
{
var varX=4000;
var varY=4000;
vGroup.coordsize=parseInt(varX/iValue)+","+parseInt(varY/iValue);
}
</script>
<center>
<input type="button" value="初始设置" onclick="InitVRML();">
<input type="button" value="柱状图" onclick="Bar(RecordSetArray.length);">
<input type="button" value="饼图" onclick="Circle(RecordSetArray.length);">
<input type="button" value="折线图" onclick="Line(RecordSetArray.length)">
<select onchange="Zoom(this.value)">
  <option value="0.2" selected>20%</option>
  <option value="0.25">25%</option>
  <option value="0.4">40%</option>
  <option value="0.5">50%</option>
  <option value="0.75">75%</option>
  <option value="0.8">80%</option>
  <option value="1">原始大小</option>
  <option value="1.25">125%</option>
  <option value="1.5">150%</option>
  <option value="2">200%</option>
  <option value="3">300%</option>
  <option value="4">400%</option>
</select>
<br>
<br>
<div id=VRMLID></div>
</center>
</body></html>