1z1-830試験無料問題集（85題）「Oracle Java SE 21 Developer Professional 認定」

出題：1

Given a properties file on the classpath named Person.properties with the content:
ini
name=James
And:
java
public class Person extends ListResourceBundle {
protected Object[][] getContents() {
return new Object[][]{
{"name", "Jeanne"}
};
}
}
And:
java
public class Test {
public static void main(String[] args) {
ResourceBundle bundle = ResourceBundle.getBundle("Person");
String name = bundle.getString("name");
System.out.println(name);
}
}
What is the given program's output?

A. Compilation fails

B. James

C. Jeanne

D. JamesJeanne

E. MissingResourceException

F. JeanneJames

正解：C 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：2

Which of the followingisn'ta correct way to write a string to a file?

A. java
try (FileOutputStream outputStream = new FileOutputStream("file.txt")) { byte[] strBytes = "Hello".getBytes(); outputStream.write(strBytes);
}

B. java
try (BufferedWriter writer = new BufferedWriter("file.txt")) {
writer.write("Hello");
}

C. None of the suggestions

D. java
Path path = Paths.get("file.txt");
byte[] strBytes = "Hello".getBytes();
Files.write(path, strBytes);

E. java
try (PrintWriter printWriter = new PrintWriter("file.txt")) {
printWriter.printf("Hello %s", "James");
}

F. java
try (FileWriter writer = new FileWriter("file.txt")) {
writer.write("Hello");
}

正解：B 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：3

Given:
java
System.out.print(Boolean.logicalAnd(1 == 1, 2 < 1));
System.out.print(Boolean.logicalOr(1 == 1, 2 < 1));
System.out.print(Boolean.logicalXor(1 == 1, 2 < 1));
What is printed?

A. Compilation fails

B. truefalsetrue

C. truetruefalse

D. truetruetrue

E. falsetruetrue

正解：B 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：4

Which of the following doesnotexist?

A. DoubleSupplier

B. BooleanSupplier

C. BiSupplier<T, U, R>

D. Supplier<T>

E. LongSupplier

F. They all exist.

正解：C 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：5

Which of the following methods of java.util.function.Predicate aredefault methods?

A. test(T t)

B. not(Predicate<? super T> target)

C. negate()

D. isEqual(Object targetRef)

E. or(Predicate<? super T> other)

F. and(Predicate<? super T> other)

正解：C,E,F 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：6

Given:
java
Object myVar = 0;
String print = switch (myVar) {
case int i -> "integer";
case long l -> "long";
case String s -> "string";
default -> "";
};
System.out.println(print);
What is printed?

A. Compilation fails.

B. string

C. long

D. integer

E. nothing

F. It throws an exception at runtime.

正解：A 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：7

Given:
java
var ceo = new HashMap<>();
ceo.put("Sundar Pichai", "Google");
ceo.put("Tim Cook", "Apple");
ceo.put("Mark Zuckerberg", "Meta");
ceo.put("Andy Jassy", "Amazon");
Does the code compile?

A. True

B. False

正解：B 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

出題：8

Given:
java
public class ExceptionPropagation {
public static void main(String[] args) {
try {
thrower();
System.out.print("Dom Perignon, ");
} catch (Exception e) {
System.out.print("Chablis, ");
} finally {
System.out.print("Saint-Emilion");
}
}
static int thrower() {
try {
int i = 0;
return i / i;
} catch (NumberFormatException e) {
System.out.print("Rose");
return -1;
} finally {
System.out.print("Beaujolais Nouveau, ");
}
}
}
What is printed?

A. Beaujolais Nouveau, Chablis, Saint-Emilion

B. Beaujolais Nouveau, Chablis, Dom Perignon, Saint-Emilion

C. Rose

D. Saint-Emilion

正解：A 解答を投票する

解説: (GoShiken メンバーにのみ表示されます)

1z1-830試験無料問題集「Oracle Java SE 21 Developer Professional 認定」