在使用OpenCSV解析csv文件时找不到类“java.beans.Introspector”

Question

我正在使用OpenCsv为我的Android应用程序解析.csv文件。我用 kotlin 编写代码。这是我的代码：

我是这样解析csv文件的:

val beans: List<csvDataClass> = CsvToBeanBuilder<csvDataClass>(FileReader(file))
            .withType(csvDataClass::class.java).build().parse()

    for (i:Int in 0..beans.size-1) {
        Log.d("Tag", " NAME = ${beans.get(i).name} Number = ${beans.get(i).phone_one_value}")
    }

这是我要将csv数据转换为的对象类。

class csvDataClass {
@CsvBindByName (column = "Name")
var name:String = ""
@CsvBindByName (column = "Phone 1 - Value")
var phone_one_value:Int = 0

constructor() {}
constructor(name: String, phone_one_value: Int) {
    this.name = name
    this.phone_one_value = phone_one_value
}

}

我已经在build.gradle文件中添加了这一行:

implementation 'com.opencsv:opencsv:4.1'

这是我的csv文件内容：

Name,Phone 1 - Value

G T，11111 11111 H K，2222222222 KK，33333 33333 P K，44444 44444

但是当我运行代码时，我得到：

05-04 16:13:31.821 25829-25829/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.pk.opencsvpoc, PID: 25829
java.lang.NoClassDefFoundError: Failed resolution of: Ljava/beans/Introspector;
    at com.opencsv.bean.HeaderColumnNameMappingStrategy.loadDescriptors(HeaderColumnNameMappingStrategy.java:372)
    at com.opencsv.bean.HeaderColumnNameMappingStrategy.loadDescriptorMap(HeaderColumnNameMappingStrategy.java:284)
    at com.opencsv.bean.HeaderColumnNameMappingStrategy.setType(HeaderColumnNameMappingStrategy.java:415)
    at com.opencsv.bean.opencsvUtils.determineMappingStrategy(opencsvUtils.java:83)
    at com.opencsv.bean.CsvToBeanBuilder.build(CsvToBeanBuilder.java:156)
    at com.example.pardeepkumar.opencsvpoc.MainActivity.readCsvFile(MainActivity.kt:46)
    at com.example.pardeepkumar.opencsvpoc.MainActivity.onCreate(MainActivity.kt:38)
    at android.app.Activity.performCreate(Activity.java:6726)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2619)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2727)
    at android.app.ActivityThread.-wrap12(ActivityThread.java)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1478)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6121)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:889)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:779)
 Caused by: java.lang.ClassNotFoundException: Didn't find class "java.beans.Introspector" on path: DexPathList[[zip file "/data/app/com.example.pk.opencsvpoc-1/base.apk", zip file "/data/app/com.example.pk.opencsvpoc-1/split_lib_dependencies_apk.apk", zip file "/data/app/com.example.pk.opencsvpoc-1/split_lib_slice_0_apk.apk", zip file "/data/app/com.example.pk.opencsvpoc-1/split_lib_slice_1_apk.apk", zip file "/data/app/com.example.pk.opencsvpoc-1/split_lib_slice_2_apk.apk", zip file "/data/app/com.example.pk.opencsvpoc-1/split_lib_slice_3_apk.apk", zip file "/data/app/com.example.pk.opencsvpoc-1/split_lib_slice_4_apk.apk", zip file "/data/app/com.example.pk.opencsvpoc-1/split_lib_slice_5_apk.apk", zip file "/data/app/com.example.pk.opencsvpoc-1/split_lib_slice_6_apk.apk", zip file "/data/app/com.example.pk.opencsvpoc-1/split_lib_slice_7_apk.apk", zip file "/data/app/com.example.pk.opencsvpoc-1/split_lib_slice_8_apk.apk", zip file "/data/app/com.example.pk.opencsvpoc-1/split_lib_slice_9_apk.apk"],nativeLibraryDirectories=[/data/app/com.example.pk.opencsvpoc-1/lib/arm64, /system/lib64, /vendor/lib64]]
    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:380)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
    at com.opencsv.bean.HeaderColumnNameMappingStrategy.loadDescriptors(HeaderColumnNameMappingStrategy.java:372) 
    at com.opencsv.bean.HeaderColumnNameMappingStrategy.loadDescriptorMap(HeaderColumnNameMappingStrategy.java:284) 
    at com.opencsv.bean.HeaderColumnNameMappingStrategy.setType(HeaderColumnNameMappingStrategy.java:415) 
    at com.opencsv.bean.opencsvUtils.determineMappingStrategy(opencsvUtils.java:83) 
    at com.opencsv.bean.CsvToBeanBuilder.build(CsvToBeanBuilder.java:156) 
    at com.example.pardeepkumar.opencsvpoc.MainActivity.readCsvFile(MainActivity.kt:46) 
    at com.example.pardeepkumar.opencsvpoc.MainActivity.onCreate(MainActivity.kt:38) 
    at android.app.Activity.performCreate(Activity.java:6726) 
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119) 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2619) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2727) 
    at android.app.ActivityThread.-wrap12(ActivityThread.java) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1478) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:154) 
    at android.app.ActivityThread.main(ActivityThread.java:6121) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:889) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:779) 

Answer 1

Android上的Bean处理需要一个外部库：openbeans。

然而，我不确定如果你把这个库添加到你的类路径中，OpenCSV是否会起作用，因为OpenBeans中的Introspector等类的包名称与原始JDK包不匹配。

你也可以试试我的库:univocity-parsers，它可以在Android上用OpenBeans生成你的类的实例。

这样使用：

CsvRoutines routines = new CsvRoutines();

for (csvDataClass bean : routines.iterate(csvDataClass.class, file)) {
        System.out.println(bean);
}

希望这有帮助。