Question

我一直在使用下面的代码为android中的jpeg图像设置dpi。打开我的应用程序时，它应该是崩溃，就像不幸的应用已经停止。这是我的代码：

import ae.java.awt.image.BufferedImage;
import ae.javax.imageio.IIOImage;
import ae.javax.imageio.ImageIO;
import ae.javax.imageio.ImageTypeSpecifier;
import ae.javax.imageio.ImageWriter;
import ae.javax.imageio.metadata.IIOInvalidTreeException;
import ae.javax.imageio.metadata.IIOMetadata;
import ae.javax.imageio.stream.ImageOutputStream;

private void setDPIJPEG()  {

        int dpi = 100;
        File infile =  new File(ScanConstants.IMAGE_RESULTS,"grayImages.jpg");
        File outfile =  new File(ScanConstants.IMAGE_RESULTS,"density.jpg");
        try {

            BufferedImage sourceImage = ImageIO.read(infile);

            ImageWriter imageWriter = ImageIO.getImageWritersBySuffix("jpeg").next();
            ImageOutputStream ios = ImageIO.createImageOutputStream(outfile);
            imageWriter.setOutput(ios);

            IIOMetadata data = imageWriter.getDefaultImageMetadata(new ImageTypeSpecifier(sourceImage), null);

            Element tree = (Element) data.getAsTree("javax_imageio_jpeg_image_1.0");
            Element jfif = (Element) tree.getElementsByTagName("app0JFIF").item(0);
            jfif.setAttribute("Xdensity", Integer.toString(dpi));
            jfif.setAttribute("Ydensity", Integer.toString(dpi));

            jfif.setAttribute("resUnits", "1"); // density is dots per inch
            data.mergeTree("javax_imageio_jpeg_image_1.0", tree);

            imageWriter.write(data, new IIOImage(sourceImage, null, data), null);
            ios.close();
            imageWriter.dispose();

        } catch (IIOInvalidTreeException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

我收到了以下错误：

09-13 16:29:30.548 29368-29368/com.scanner.demo E/AndroidRuntime: FATAL EXCEPTION: main
                                                                  Process: com.scanner.demo, PID: 29368
                                                                  java.lang.NoClassDefFoundError: sun.awt.AppContext
                                                                      at ae.javax.imageio.spi.IIORegistry.getDefaultInstance(IIORegistry.java:155)
                                                                      at ae.javax.imageio.ImageIO.<clinit>(ImageIO.java:65)
                                                                      at com.scanlibrary.ResultFragment.setDPIJPEG(ResultFragment.java:269)
                                                                      at com.scanlibrary.ResultFragment.access$600(ResultFragment.java:46)
                                                                      at com.scanlibrary.ResultFragment$1.onClick(ResultFragment.java:129)
                                                                      at android.view.View.performClick(View.java:4633)
                                                                      at android.view.View$PerformClick.run(View.java:19274)
                                                                      at android.os.Handler.handleCallback(Handler.java:733)
                                                                      at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                      at android.os.Looper.loop(Looper.java:146)
                                                                      at android.app.ActivityThread.main(ActivityThread.java:5593)
                                                                      at java.lang.reflect.Method.invokeNative(Native Method)
                                                                      at java.lang.reflect.Method.invoke(Method.java:515)
                                                                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
                                                                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
                                                                      at dalvik.system.NativeStart.main(Native Method)

这是我的build.gradle文件

apply plugin: 'com.android.library'

android {
    compileSdkVersion 25
    buildToolsVersion '25.0.3'

    defaultConfig {
        minSdkVersion 14
        targetSdkVersion 21
        versionCode 1
        versionName "1.0"
        ndk
                {
                    moduleName "Scanner"

                }
        multiDexEnabled true
    }
    sourceSets.main
            {
                jni.srcDirs = []
                jniLibs.srcDir 'src/main/libs'
            }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile 'com.github.beyka:androidtiffbitmapfactory:0.9.7.6'
    compile 'com.android.support:appcompat-v7:25.3.1'
    compile project(path: ':openCVLibrary310')
    compile 'com.android.support:multidex:1.0.1'
    compile files('libs/ae-awt.jar')
}

这是扫描库是我的应用程序中的一个模块。如何解决它。如果有人知道，请帮助我。我使用的是Android Studio 2.3.3 java 1.8。

Answer 1

com.scanlibrary未设置为与Android配合使用。如果这是第三方代码，请切换到适用于Android的库。

如果com.scanlibrary 您的代码...您导入了一堆不属于Android SDK的ae类。这些类又包含对JDK中的类的引用（例如，sun.awt.AppContext），这些类不是Android的一部分。因此，ae类未设置为与Android一起使用。切换到适用于Android的库。

如何在android中解析java.lang.NoClassDefFoundError：sun.awt.AppContext

1 个答案: