课后习题，仅供参考。
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Random;
public class CollectionsTest {
public void testSort1(){
List<Integer> integerList = new ArrayList<Integer>();
Random random = new Random();
Integer k;
for(int i=0; i<10; i++ ){
do{
k = random.nextInt(100);
}while (integerList.contains(k));
integerList.add(k);
}
System.out.println("-----------Before Sorting--------");
for(Integer integer: integerList){
System.out.println(integer);
}
Collections.sort(integerList);
System.out.println("-----------After Sorting---------");
for(Integer integer: integerList){
System.out.println(integer);
}
}
public void testSort2(){
List<String> stringList = new ArrayList<String>();
stringList.add("Apple");
stringList.add("Microsoft");
stringList.add("Google");
System.out.println("-------Before Sorting-------");
for(String string: stringList){
System.out.println(string);
}
Collections.sort(stringList);
System.out.println("-------After Sorting-------");
for(String string: stringList){
System.out.println(string);
}
}
public void testSort3(){
List<String> integerList = new ArrayList<String>();
String string = "1234567890qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM";
Random random = new Random();
for(int i=0; i<10; i++ ){
String str = "";
do{
int a = random.nextInt(string.length());
for(int j=0; j<a; j++){
int k = random.nextInt(string.length());
char m = string.charAt(k);
str = str + m;
}
}while (integerList.contains(str));
integerList.add(str);
}
System.out.println("-----------Before Sorting--------");
for(String str: integerList){
System.out.println(str);
}
Collections.sort(integerList);
System.out.println("-----------After Sorting---------");
for(String str: integerList){
System.out.println(str);
}
}
public static void main(String[] args) {
// TODO Auto-generated method stub
CollectionsTest ct = new CollectionsTest();
// ct.testSort1();
// ct.testSort2();
ct.testSort3();
}
}
