jasperreport applet 打印问题？？？？

[melack_2008]

异常：java.lang.NoClassDefFoundError:
net/sf/jasperreports/engine/print/JRPrinterAWT$1
版本3.7.2 包内没有JRPrinterAWT$1.class这个文件

Exception in thread "thread applet-PrinterApplet.class-1" java.lang.NoClassDefFoundError: net/sf/jasperreports/engine/print/JRPrinterAWT$1
	at net.sf.jasperreports.engine.print.JRPrinterAWT.printPages(JRPrinterAWT.java:143)
	at net.sf.jasperreports.engine.print.JRPrinterAWT.printPages(JRPrinterAWT.java:84)
	at net.sf.jasperreports.engine.JasperPrintManager.printPages(JasperPrintManager.java:350)
	at net.sf.jasperreports.engine.JasperPrintManager.printReport(JasperPrintManager.java:241)
	at PrinterApplet.start(PrinterApplet.java:44)
	at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: net.sf.jasperreports.engine.print.JRPrinterAWT$1
	at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	at java.lang.ClassLoader.loadClass(Unknown Source)
	... 7 more
Caused by: java.io.IOException: open HTTP connection failed:http://127.0.0.1/applet/net/sf/jasperreports/engine/print/JRPrinterAWT$1.class
	at sun.plugin2.applet.Applet2ClassLoader.getBytes(Unknown Source)
	at sun.plugin2.applet.Applet2ClassLoader.access$000(Unknown Source)
	at sun.plugin2.applet.Applet2ClassLoader$1.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	... 10 more

applet代码：

import java.applet.Applet;
import java.net.URL;
import javax.swing.JOptionPane;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.JasperPrintManager;
import net.sf.jasperreports.engine.util.JRLoader;

public class PrinterApplet extends Applet {
	private static final long serialVersionUID = 4948181907178944882L;
	private URL url = null;
	private JasperPrint jasperPrint = null;

	public PrinterApplet() {

	}

	public void init() {
		String strUrl = getParameter("REPORT_URL");
		if (strUrl != null) {
			try {
				url = new URL(getCodeBase(), strUrl);
			} catch (Exception e) {
				JOptionPane.showMessageDialog(this, e.getMessage());
			}
		} else {
			JOptionPane.showMessageDialog(this, "Source URL not specified");
		}
	}

	@Override
	public void start() {
		if (url != null) {
			if (jasperPrint == null) {
				try {
					jasperPrint = (JasperPrint) JRLoader.loadObject(url);
				} catch (Exception e) {
					JOptionPane.showMessageDialog(this, e.getStackTrace());
				}
			}

			if (jasperPrint != null) {
				final JasperPrint print = jasperPrint;
				try {
					JasperPrintManager.printReport(print, true);
				} catch (Exception e) {
					JOptionPane.showMessageDialog(this, e.getMessage());
				}
			} else {
				JOptionPane.showMessageDialog(this, "Empty report.");
			}
		} else {
			JOptionPane.showMessageDialog(this, "Source URL not specified");
		}
	}

}

[牛叔]

[生活]

这是类加载器的问题，类加载器规范有定，父类加载器不能加载子类加载器里的类

回帖是美德
结贴也是美德
结贴率0% 都没人回答你了
还有你结贴的话会返还给你50%的分 不结贴和 无答案都不会返回

[kdflove]

我最近刚刚也碰到java.lang.NoClassDefFoundError这个问题，搞了很久，
最后发现是jar包的问题，有部分损坏，你可以重新用一个jar包。

[japt88_115656292]

这是类加载器的问题，类加载器规范有定，父类加载器不能加载子类加载器里的类

回帖是美德
结贴也是美德
结贴率0% 都没人回答你了
还有你结贴的话会返还给你50%的分 不结贴和 无答案都不会返回


jf

[长公子冰]

我今天也遇到这个问题了，官方例子打印没问题，同样的文件，同样的代码放到我的项目里就报这个异常。我都要崩溃了，不知如何是好。昨天还打印了呢，今天一来就。。。。。杯具啊。。。。