java类中生成jfreechart,返回图表的url地址 代码分享

<servlet>
<servlet-name>displaychart</servlet-name>
<servlet-class>org.jfree.chart.servlet.displaychart</servlet-class>
</servlet >
<servlet-mapping>
<servlet-name>displaychart</servlet-name>
<url-pattern>/displaychart</url-pattern>
</servlet-mapping>

public string getchart(string series[],double score[][],string type[],string name){
final int num=8;
defaultcategorydataset defaultcategorydataset = new defaultcategorydataset();
for(int i=0;i<type.length;i++){ 
type[i]=type[i].substring(0, (type[i].length()<num)?type[i].length():num);
}

for(int j=0;j<series.length;j++){
int i=0;
for( i=0;i<type.length;i++){
defaultcategorydataset.addvalue(score[j][i], series[j], type[i]); 
}
}

jfreechart jfreechart = chartfactory.createlinechart(name,null,null,defaultcategorydataset,plotorientation.vertical,true,true,false);

jfreechart.getlegend().setposition(rectangleedge.right);

jfreechart.setbackgroundpaint(color.white);

categoryplot categoryplot = (categoryplot)jfreechart.getplot();
categoryplot.setnodatamessage("无数据可供显示！");
categoryplot.setbackgroundpaint(color.white);
categoryplot.setdomaingridlinesvisible(true);
categoryplot.setrangegridlinesvisible(true);
categoryplot.setrangegridlinepaint(color.gray);
categoryplot.setdomaingridlinepaint(color.gray);
categoryplot.setbackgroundalpha(0.8f);
font font1 = new font("黑体",font.bold, 14);
jfreechart.gettitle().setfont(font1);

font font3 = new font("隶书",font.bold, 12);
jfreechart.getlegend().setitemfont(font3);

categoryaxis categoryaxis = categoryplot.getdomainaxis();
//  categoryaxis.setcategorylabelpositions(categorylabelpositions.up_45);
categoryaxis.setmaximumcategorylabellines(10);//行数，根据需要自己设
categoryaxis.setmaximumcategorylabelwidthratio(0.5f);//每行宽度，这里设一个汉字宽

numberaxis numberaxis = (numberaxis)categoryplot.getrangeaxis();
numberaxis.setstandardtickunits(numberaxis.createintegertickunits());
numberaxis.setautorangeincludeszero(true);
numberaxis.setrangewithmargins(0, 3);

numberaxis.setuppermargin(0.8);////设置最高的一个 item 与图片顶端的距离
numberaxis.setupperbound(3.5);//纵坐标最大值

categoryaxis.setticklabelfont(new font("宋体", font.bold, 12));
numberaxis.setticklabelfont(new font("隶书", font.bold, 12));
font font2 = new font("simsun", font.bold, 16);
categoryaxis.setlabelfont(font2);
numberaxis.setlabelfont(font2);
categoryplot.setaxisoffset(new rectangleinsets(0d, 0d,0d, 10d));//设置曲线图与xy轴的距离
lineandshaperenderer lineandshaperenderer = (lineandshaperenderer)categoryplot.getrenderer();
lineandshaperenderer.setshapesvisible(true); //数据点可见

lineandshaperenderer.setseriesstroke(0, new basicstroke(2.0f, 1, 1, 1.0f, new float[] {
10f, 6f
}, 0.0f)); //定义series点之间的连线 ，这里是虚线，默认是直线
lineandshaperenderer.setseriesstroke(1, new basicstroke(2.0f, 1, 1, 1.0f, new float[] {
6f, 6f
}, 0.0f));

lineandshaperenderer.setbaseitemlabelsvisible(true);
lineandshaperenderer.setbaseitemlabelgenerator(new standardcategoryitemlabelgenerator());

chartrenderinginfo info=new chartrenderinginfo(new standardentitycollection());
string filename = null;
try
{
filename = servletutilities.savechartaspng(jfreechart, 700,300, info, null);//生成图片
}
catch (ioexception e)
{
e.printstacktrace();
}

string graphurl = "/projectname/displaychart?filename=" + filename; //projectname为对应项目的路径path,一般就是项目名称

//jsp中这样使用： string graphurl = request.getcontextpath() + "/servlet/displaychart?filename=" + filename;
return graphurl;//返回生成图片的地址
}

　　 getchart(stus,score_field,type,"总分图");