字符串数组到java中的Array List问题

Question

我在java collection util中面临一些问题,基本上我通过打破这些步骤在arrayList上使用了removeall ()但它抛出java.lang.UnsupportedOperationException,当我在单行中执行它时,它按预期正常工作.所以当我分几个步骤打破它时,我不明白是什么问题.代码是

public class Test4 {

public static void main(String args[]){
    String unInstall="com.mobikwik_new,com.cleanmaster.mguard,com.htc.flashlight,com.mobilemotion.dubsmash";
    String  install="com.mobikwik_new,com.cleanmaster.mguard,com.htc.flashlight";
    List<String> installList = new ArrayList<String>();
    List<String> unInstallList = new ArrayList<String>();
    String inL[] = install.split(",");
    String UnInL[] = unInstall.split(",");
    installList = Arrays.asList(inL);
    unInstallList = Arrays.asList(UnInL);
    unInstallList.remove(installList);
    //List<String> installList = new ArrayList<>(Arrays.asList(install.split(",")));
    //List<String> unInstallList = new ArrayList<>(Arrays.asList(unInstall.split(",")));

    unInstallList.removeAll(installList);

    System.out.println("unInstall : "+unInstallList);
}
}

注意:当我只使用注释行而不是上述所有步骤时,它的工作正常

投掷的例外是 -

Exception in thread "main" java.lang.UnsupportedOperationException
at java.util.AbstractList.remove(Unknown Source)
at java.util.AbstractList$Itr.remove(Unknown Source)
at java.util.AbstractCollection.removeAll(Unknown Source)
at Test4.main(Test4.java:21)

谢谢 !

Answer 1

Arrays.asList返回一个固定大小的列表,因为它由作为参数给出的数组支持.返回的列表不支持该remove操作,如您所看到的错误消息所示.

如果要从列表中删除某些内容,请将返回的列表包装在ArrayList:中new ArrayList<>(Arrays.asList(inL));.