Oracle 1z0-809 問題集

質問 1：
Given the code fragments:
class TechName {
String techName;
TechName (String techName) {
this.techName=techName;
}
}
and
List<TechName> tech = Arrays.asList (
new TechName("Java-"),
new TechName("Oracle DB-"),
new TechName("J2EE-")
);
Stream<TechName> stre = tech.stream();
//line n1
Which should be inserted at line n1 to print Java-Oracle DB-J2EE-?
A. stre.map(a-> a.techName).forEach(System.out::print);
B. stre.forEach(System.out::print);
C. stre.map(a-> a).forEachOrdered(System.out::print);
D. stre.forEachOrdered(System.out::print);
正解：A

質問 2：
Given the code fragment:
Path path1 = Paths.get("/app/./sys/");
Path res1 = path1.resolve("log");
Path path2 = Paths.get("/server/exe/");
Path res1 = path1.resolve("/readme/");
System.out.println(res1);
System.out.println(res2);
What is the result?
A. /app/./sys/log/readme
B. /app/sys/log/readme/server/exe
C. /app/log/sys/server/exe/readme
D. /app/./sys/log/server/exe/readme
正解：A

質問 3：
Given the definition of the Emp class:
public class Emp
private String eName;
private Integer eAge;
Emp(String eN, Integer eA) {
this.eName = eN;
this.eAge = eA;
}
public Integer getEAge () {return eAge;}
public String getEName () {return eName;}
}
and code fragment:
List<Emp>li = Arrays.asList(new Emp("Sam", 20), New Emp("John", 60), New Emp("Jim", 51)); Predicate<Emp> agVal = s -> s.getEAge() > 50;//line n1 li = li.stream().filter(agVal).collect(Collectors.toList()); Stream<String> names = li.stream()map.(Emp::getEName);//line n2 names.forEach(n -> System.out.print(n + " ")); What is the result?
A. John Jim
B. A compilation error occurs at line n2.
C. A compilation error occurs at line n1.
D. Sam John Jim
正解：A

質問 4：
Given the code fragment:

What is the result?
A. [X][X, X][X, X, X][X, X, X, X]
B. [X, X]
C. [X][X, X][X, X, X]
D. [X, X][X, X, X, X]
正解：A

質問 5：
Which two reasons should you use interfaces instead of abstract classes? (Choose two.)
A. You expect that classes that implement your interfaces have many common methods or fields, or require access modifiers other than public.
B. You want to share code among several closely related classes.
C. You want to take advantage of multiple inheritance of type.
D. You expect that unrelated classes would implement your interfaces.
E. You want to declare non-static on non-final fields.
正解：C,D

質問 6：
Given:
Item table
* ID, INTEGER: PK
* DESCRIP, VARCHAR(100)
* PRICE, REAL
* QUANTITY< INTEGER
And given the code fragment:
9. try {
10.Connection conn = DriveManager.getConnection(dbURL, username, password);
11. String query = "Select * FROM Item WHERE ID = 110";
12. Statement stmt = conn.createStatement();
13. ResultSet rs = stmt.executeQuery(query);
14.while(rs.next()) {
15.System.out.println("ID:" + rs.getString(1));
16.System.out.println("Description:" + rs.getString(2));
17.System.out.println("Price:" + rs.getString(3));
18. System.out.println(Quantity:" + rs.getString(4));
19.}
20. } catch (SQLException se) {
21. System.out.println("Error");
22. }
Assume that:
The required database driver is configured in the classpath.
The appropriate database is accessible with the dbURL, userName, and passWord exists.
The SQL query is valid.
What is the result?
A. The code prints Error.
B. An exception is thrown at runtime.
C. Compilation fails.
D. The code prints information about Item 110.
正解：C

質問 7：
Given:

and the code fragment:

What is the result?
A. 0
B. 2
C. An Exception is thrown at run time.
D. A compilation error occurs at line n1.
正解：D

質問 8：
Which statement is true about the DriverManager class?
A. It executes SQL statements against the database.
B. it is written by different vendors for their specific database.
C. It returns an instance of Connection.
D. It only queries metadata of the database.
正解：C
解説: (Topexam メンバーにのみ表示されます)

質問 9：
Given:
class Worker extends Thread {
CyclicBarrier cb;
public Worker(CyclicBarrier cb) { this.cb = cb; }
public void run () {
try {
cb.await();
System.out.println("Worker...");
} catch (Exception ex) { }
}
}
class Master implements Runnable { //line n1
public void run () {
System.out.println("Master...");
}
}
and the code fragment:
Master master = new Master();
//line n2
Worker worker = new Worker(cb);
worker.start();
You have been asked to ensure that the run methods of both the Worker and Master classes are executed.
Which modification meets the requirement?
A. Replace line n1 with class Master extends Thread {
B. At line n2, insert CyclicBarrier cb = new CyclicBarrier(1, master);
C. At line n2, insert CyclicBarrier cb = new CyclicBarrier(2, master);
D. At line n2, insert CyclicBarrier cb = new CyclicBarrier(master);
正解：B