将jfreechart-0.9.6.zip解压。 然后将jfreechart-0.9.6.jar和lib里面的jcommon-0.7.2.jar两个文件加入Classpath。主要使用com.jrefinery.chart.ChartFactory生成各种不同的JFreeChart对象。然后产生图片,显示出来。 另外用DefaultPieDataset类生成需要显示的数据集合。下面我做了一个applet显示图表。Applet1.java ---------------------------- package testjdbc;import java.awt.*; import java.awt.event.*; import java.applet.*; import com.jrefinery.chart.*; import com.jrefinery.data.*; import java.awt.image.*;public class Applet1 extends Applet { boolean isStandalone = false; String var0; //Get a parameter value public String getParameter(String key, String def) { return isStandalone ? System.getProperty(key, def) : (getParameter(key) != null ? getParameter(key) : def); } //Construct the applet public Applet1() { } public void paint(Graphics g){ DefaultPieDataset pieDataset = new DefaultPieDataset(); pieDataset.setValue("JavaWorld", new Integer(75)); pieDataset.setValue("Other", new Integer(25)); com.jrefinery.chart.JFreeChart chart1 = com.jrefinery.chart.ChartFactory.createPieChart("aaa",pieDataset,true,true,true); BufferedImage image = chart1.createBufferedImage(500,300); g.drawImage(image,0,0,this); super.paint(g); } //Initialize the applet public void init() { try { jbInit(); } catch(Exception e) { e.printStackTrace(); } } //Component initialization private void jbInit() throws Exception { } //Get Applet information public String getAppletInfo() { return "Applet Information"; } //Get parameter info public String[][] getParameterInfo() { String[][] pinfo = { {"name", "String", ""}, }; return pinfo; } }------------------------------------------------- Applet1.html ------------------------------------------------- <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=GB2312"> <title> HTML Test Page </title> </head> <body> testjdbc.Applet1 will appear below in a Java enabled browser.<br> <applet codebase = "." code = "testjdbc.Applet1.class" name = "TestApplet" width = "400" height = "300" hspace = "0" vspace = "0" align = "top" > <param name = "name" value = "FreeChart"> </applet> </body> </html>
我运行上面的例子时,出现以下问题: D:\learning>javac Applet3.javaD:\learning>appletviewer Applet3.html java.lang.NoClassDefFoundError: org/jfree/data/PieDataset at java.lang.Class.getDeclaredConstructors0(Native Method) at java.lang.Class.privateGetDeclaredConstructors(Class.java:1576) at java.lang.Class.getConstructor0(Class.java:1748) at java.lang.Class.newInstance0(Class.java:266) at java.lang.Class.newInstance(Class.java:249) at sun.applet.AppletPanel.createApplet(AppletPanel.java:548) at sun.applet.AppletPanel.runLoader(AppletPanel.java:477) at sun.applet.AppletPanel.run(AppletPanel.java:290) at java.lang.Thread.run(Thread.java:536)版本是:0.9.8 请问怎么解决?
然后将jfreechart-0.9.6.jar和lib里面的jcommon-0.7.2.jar两个文件加入Classpath。主要使用com.jrefinery.chart.ChartFactory生成各种不同的JFreeChart对象。然后产生图片,显示出来。
另外用DefaultPieDataset类生成需要显示的数据集合。下面我做了一个applet显示图表。Applet1.java
----------------------------
package testjdbc;import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import com.jrefinery.chart.*;
import com.jrefinery.data.*;
import java.awt.image.*;public class Applet1 extends Applet {
boolean isStandalone = false;
String var0;
//Get a parameter value
public String getParameter(String key, String def) {
return isStandalone ? System.getProperty(key, def) :
(getParameter(key) != null ? getParameter(key) : def);
} //Construct the applet
public Applet1() {
} public void paint(Graphics g){
DefaultPieDataset pieDataset = new DefaultPieDataset();
pieDataset.setValue("JavaWorld", new Integer(75));
pieDataset.setValue("Other", new Integer(25));
com.jrefinery.chart.JFreeChart chart1 = com.jrefinery.chart.ChartFactory.createPieChart("aaa",pieDataset,true,true,true);
BufferedImage image = chart1.createBufferedImage(500,300); g.drawImage(image,0,0,this);
super.paint(g);
}
//Initialize the applet
public void init() {
try {
jbInit();
}
catch(Exception e) {
e.printStackTrace();
}
}
//Component initialization
private void jbInit() throws Exception {
}
//Get Applet information
public String getAppletInfo() {
return "Applet Information";
}
//Get parameter info
public String[][] getParameterInfo() {
String[][] pinfo =
{
{"name", "String", ""},
};
return pinfo;
}
}-------------------------------------------------
Applet1.html
-------------------------------------------------
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GB2312">
<title>
HTML Test Page
</title>
</head>
<body>
testjdbc.Applet1 will appear below in a Java enabled browser.<br>
<applet
codebase = "."
code = "testjdbc.Applet1.class"
name = "TestApplet"
width = "400"
height = "300"
hspace = "0"
vspace = "0"
align = "top"
>
<param name = "name" value = "FreeChart">
</applet>
</body>
</html>
D:\learning>javac Applet3.javaD:\learning>appletviewer Applet3.html
java.lang.NoClassDefFoundError: org/jfree/data/PieDataset
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:1576)
at java.lang.Class.getConstructor0(Class.java:1748)
at java.lang.Class.newInstance0(Class.java:266)
at java.lang.Class.newInstance(Class.java:249)
at sun.applet.AppletPanel.createApplet(AppletPanel.java:548)
at sun.applet.AppletPanel.runLoader(AppletPanel.java:477)
at sun.applet.AppletPanel.run(AppletPanel.java:290)
at java.lang.Thread.run(Thread.java:536)版本是:0.9.8 请问怎么解决?