Oracle Upgrade to Java SE 7 Programmer (1Z0-805日本語版) - 1Z0-805日本語 Exam Practice Test

public class SampleClass {
public static void main(String[] args) {
SampleClass sc = new SampleClass();
sc.processCD();
}
private void processCD() {
try (CDStream cd = new CDStream()) {
cd.open();
cd.read();
cd.write("lullaby");
cd.close();
} catch (Exception e) {
System.out.println("Exception thrown");
}
}
class CDStream {
String cdContents = null;
public void open() {
cdContents = "CD Contents";
System.out.println("Opened CD stream");
}
public String read() throws Exception {
throw new Exception("read error");
}
public void write(String str) {
System.out.println("CD str is: " + str);
}
public void close() {
cdContents = null;
}

public class MyGrades {
private final List<Integer> myGrades = new ArrayList<Integer>();
private final ReadWriteLock rwlock = new ReentrantReadWriteLock();
public void addGrade(Integer grade) {
/*
lock and modify
*/
}
public void averageGrades() {
// acquire _______ lock Line **
double sum = 0;
int i = 0;
for (i = 0; i < myGrades.size(); i++) {
sum += myGrades.get(i);
}
// release __________ lock Line ***
System.out.println("The average is: " + sum/(i+1));
}
}

public class DAOManager {
public AccountDAO getAccountDAO() {
return new AccountJDBCDAO();
}
}