Java异常-线程"main"中的异常； java.lang.NoClassDefFoundError:net/sourceforge/tess4 j/Tesseract

问题描述

我试图使事情与tess4j(OCR算法)一起工作，我使用以下代码:

I am try to make things works with tess4j (OCR algorithm), and i m using this code:

import java.awt.image.RenderedImage;
import java.io.File;
import java.net.URL;

import javax.imageio.ImageIO;
import net.sourceforge.tess4j.*;

public static void main(String[] args) throws Exception{

    URL imageURL = new URL("http://s4.postimg.org/e75hcme9p/IMG_20130507_190237.jpg");

    RenderedImage img = ImageIO.read(imageURL);
    File outputfile = new File("saved.png");
    ImageIO.write(img, "png", outputfile);

    try {
    Tesseract instance = Tesseract.getInstance(); // JNA Interface Mapping

    //   Tesseract1 instance = new Tesseract1(); // JNA Direct Mapping

        String result = instance.doOCR(outputfile);
        System.out.println(result);

    } catch (Exception e) {
        System.err.println(e.getMessage());
    }

}

当我在Eclipse(juno-64bit)中运行它时，它运行完美！

When i run it in Eclipse (juno-64bit) it works perfect!

但是从命令行我得到了这个异常:

But from the command line i get this Exception:

Exception in thread "main" java.lang.NoClassDefFoundError: net/sourceforge/tess4j/Tesseract
    at SimpleQueueServiceSample.testOCR(SimpleQueueServiceSample.java:73)
    at SimpleQueueServiceSample.main(SimpleQueueServiceSample.java:57)Caused by: java.lang.ClassNotFoundException: net.sourceforge.tess4j.Tesseract
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    ... 2 more

在我的构建类路径中，我有正确的jar文件:

In my build class path, i hame the correct jars files:

tess4j.jar
jai_imageio.jar

此后，我导出一个简单的jar文件(jar在构建路径中的"order and export"处签名)，然后运行我的代码:

After that i export a simple jar file (the jars are sign at 'order and export' in the build path), and run my code:

java -jar manager.jar

请帮助！

推荐答案

您的 jar文件清单应包含类路径条目:

Class-Path: tess4j.jar jai_imageio.jar

然后在执行时将这些jar文件放置在与jar文件相同的目录中，以便可以适当地加载它们.

Those jar files should then be placed in the same directory as your jar file at execution time, so they can be loaded appropriately.

到那时，一切都应该很好.但是，如果清单中没有该条目，则无法将您的jar文件与其依赖的其他jar文件连接起来.

At that point, all should be well. But without that entry in the manifest, there's nothing to connect your jar file with the other jar files it depends on.

这篇关于Java异常-线程"main"中的异常； java.lang.NoClassDefFoundError:net/sourceforge/tess4 j/Tesseract的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！