Skip to content

Commit 21071ef

Browse files
limicalalimicala
committed
think in java
1 parent 7c18bb7 commit 21071ef

File tree

13 files changed

+424
-0
lines changed

13 files changed

+424
-0
lines changed

‎src/test/java/org/thinkinjava/initialization/Mugs.java

+45
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,45 @@
1+
package org.thinkinjava.initialization;
2+
3+
/**
4+
* 实例初始化子句
5+
* {
6+
* xxx;
7+
* xxx;
8+
* }
9+
*/
10+
class Mug {
11+
Mug (int marker) {
12+
System.out.println("Mug(" + marker + ")");
13+
}
14+
15+
void f (int marker) {
16+
System.out.println("f(" + marker + ")");
17+
}
18+
}
19+
20+
21+
public class Mugs {
22+
Mug mug1;
23+
Mug mug2;
24+
{
25+
mug1 = new Mug(1);
26+
mug2 = new Mug(2);
27+
System.out.println("mug1 & mug2 initialized");
28+
}
29+
30+
Mugs() {
31+
System.out.println("Mugs()");
32+
}
33+
34+
Mugs(int marker){
35+
System.out.println("Mugs(int)");
36+
}
37+
38+
public static void main(String[] args) {
39+
System.out.println("Inside main()");
40+
new Mugs();
41+
System.out.println("new Mugs() completed");
42+
new Mugs(1);
43+
System.out.println("new Mugs(1) completed");
44+
}
45+
}

‎src/test/java/org/thinkinjava/initialization/OverloadingVarargs2.java

+15
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,15 @@
1+
package org.thinkinjava.initialization;
2+
3+
public class OverloadingVarargs2 {
4+
static void f(float i, Character... args){
5+
System.out.println("first");
6+
}
7+
static void f(Character... args){
8+
System.out.println("second");
9+
}
10+
11+
public static void main(String[] args) {
12+
f(1, 'a');
13+
f('a', 'b');
14+
}
15+
}

‎src/test/java/org/thinkinjava/initialization/StaticInitialization.java

+55
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,55 @@
1+
package org.thinkinjava.initialization;
2+
3+
/**
4+
* 初始化的顺序是
5+
* 先初始化静态对象
6+
* 类里面的其它属性会按照定义的顺序来初始化
7+
*/
8+
class Bowl{
9+
Bowl(int marker) {
10+
System.out.println("Bowl(" + marker + ")");
11+
}
12+
13+
void f1(int marker){
14+
System.out.println("f1(" + marker + ")");
15+
}
16+
}
17+
18+
class Table{
19+
static Bowl bowl1 = new Bowl(1);
20+
Table() {
21+
System.out.println("Table()");
22+
bowl1.f1(1);
23+
}
24+
void f2(int marker) {
25+
System.out.println("f2(" + marker + ")");
26+
}
27+
static Bowl bowl2 = new Bowl(2);
28+
}
29+
30+
class Cupboard {
31+
Bowl bowl3 = new Bowl(3);
32+
static Bowl bowl4 = new Bowl(4);
33+
34+
Cupboard() {
35+
System.out.println("Cupboard()");
36+
bowl4.f1(2);
37+
}
38+
void f3(int marker) {
39+
System.out.println("f3(" + marker + ")");
40+
}
41+
static Bowl bowl5 = new Bowl(5);
42+
}
43+
public class StaticInitialization {
44+
public static void main(String[] args) {
45+
System.out.println("Creating new Cupboard() in main");
46+
new Cupboard();
47+
System.out.println("Creating new Cupboard() in main");
48+
new Cupboard();
49+
table.f2(1);
50+
cupboard.f3(1);
51+
}
52+
53+
static Table table = new Table();
54+
static Cupboard cupboard = new Cupboard();
55+
}

‎src/test/java/org/thinkinjava/innerclasses/Outer.java

+25
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,25 @@
1+
package org.thinkinjava.innerclasses;
2+
3+
/**
4+
* 练习1
5+
* 编写一个名为Outer的类，它包含一个名为Inner的类。
6+
* 在Outer中添加一个方法，它返回一个Inner类型的对象。
7+
* 在main()中，创建并初始化一个指向某个Inner对象的引用。
8+
*/
9+
10+
public class Outer {
11+
12+
class Inner {
13+
14+
}
15+
public Inner inners(){
16+
return new Inner();
17+
}
18+
19+
public static void main(String[] args) {
20+
// 先创建外部类对象
21+
Outer outer = new Outer();
22+
23+
Outer.Inner inner = outer.inners();
24+
}
25+
}

‎src/test/java/org/thinkinjava/innerclasses/Sequence.java

+49
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,49 @@
1+
package org.thinkinjava.innerclasses;
2+
3+
//: innerclasses/Sequence.java
4+
// Holds a sequence of Objects.
5+
6+
interface Selector {
7+
boolean end();
8+
Object current();
9+
void next();
10+
}
11+
12+
public class Sequence {
13+
private Object[] items;
14+
private int next = 0;
15+
public Sequence(int size) { items = new Object[size]; }
16+
public void add(Object x) {
17+
if(next < items.length)
18+
items[next++] = x;
19+
}
20+
private class SequenceSelector implements Selector {
21+
private int i = 0;
22+
public boolean end() { return i == items.length; }
23+
public Object current() { return items[i]; }
24+
public void next() { if(i < items.length) i++; }
25+
26+
/**
27+
* 练习四
28+
* 在Sequence.SequenceSelector类中增加一个方法，它可以生成堆外部类Sequence的引用
29+
*/
30+
public Sequence sequence(){
31+
return Sequence.this;
32+
}
33+
}
34+
public Selector selector() {
35+
return new SequenceSelector();
36+
}
37+
public static void main(String[] args) {
38+
Sequence sequence = new Sequence(10);
39+
for(int i = 0; i < 10; i++)
40+
sequence.add(Integer.toString(i));
41+
Selector selector = sequence.selector();
42+
while(!selector.end()) {
43+
System.out.print(selector.current() + " ");
44+
selector.next();
45+
}
46+
}
47+
} /* Output:
48+
0 1 2 3 4 5 6 7 8 9
49+
*///:~

‎src/test/java/org/thinkinjava/innerclasses/exercise02.java

+34
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,34 @@
1+
package org.thinkinjava.innerclasses;
2+
3+
/**
4+
* 练习2
5+
* 创建一个类，它持有一个String，并且有一个显示这个String的toString()方法。
6+
* 将你的新类的若干个对象添加到一个Sequence对象中，然后显示它们。
7+
*/
8+
class StringObject {
9+
public String name;
10+
11+
public StringObject(String name){
12+
this.name = name;
13+
}
14+
public String toString(){
15+
return name;
16+
}
17+
}
18+
public class exercise02 {
19+
20+
public static void main(String[] args) {
21+
Sequence sequence = new Sequence(5);
22+
23+
for(int i = 0; i < 5; i++){
24+
sequence.add(new StringObject("obj" + i));
25+
}
26+
27+
Selector selector = sequence.selector();
28+
29+
while (!selector.end()){
30+
System.out.println(selector.current());
31+
selector.next();
32+
}
33+
}
34+
}

‎src/test/java/org/thinkinjava/innerclasses/exercise05.java

+23
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,23 @@
1+
package org.thinkinjava.innerclasses;
2+
3+
/**
4+
* 练习五
5+
* 创建一个包含内部类的类，
6+
* 在另一个独立的类中，创建此内部类的实例
7+
*/
8+
class OutA{
9+
class InnerA{
10+
void print(){
11+
System.out.println("--------");
12+
}
13+
}
14+
}
15+
public class exercise05 {
16+
public static void main(String[] args) {
17+
OutA outA = new OutA();
18+
19+
OutA.InnerA oia = outA.new InnerA();
20+
21+
oia.print();
22+
}
23+
}

‎src/test/java/org/thinkinjava/innerclasses/exercise6/package1/MyInterface.java

+13
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,13 @@
1+
package org.thinkinjava.innerclasses.exercise6.package1;
2+
3+
/**
4+
* 练习六
5+
* 在第一个包中创建一个至少有一个方法的接口。
6+
* 然后在第二个包内创建一个类，
7+
* 在其中增加一个protected的内部类以实现那个接口。
8+
* 在第三个包中，继承这个类，并在一个方法中返回该protected内部类的对象，
9+
* 在返回的时候向上转型为第一个包中的接口的类型
10+
*/
11+
public interface MyInterface {
12+
void print();
13+
}

‎src/test/java/org/thinkinjava/innerclasses/exercise6/package2/MyInnerImpl.java

+16
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,16 @@
1+
package org.thinkinjava.innerclasses.exercise6.package2;
2+
3+
import org.thinkinjava.innerclasses.exercise6.package1.MyInterface;
4+
5+
public class MyInnerImpl {
6+
7+
protected class MyInner implements MyInterface{
8+
9+
public MyInner(){}
10+
11+
@Override
12+
public void print() {
13+
System.out.println("MyInner.print()");
14+
}
15+
}
16+
}

‎src/test/java/org/thinkinjava/innerclasses/exercise6/package3/MyExtendsImpl.java

+12
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,12 @@
1+
package org.thinkinjava.innerclasses.exercise6.package3;
2+
3+
import org.thinkinjava.innerclasses.exercise6.package1.MyInterface;
4+
import org.thinkinjava.innerclasses.exercise6.package2.MyInnerImpl;
5+
6+
public class MyExtendsImpl extends MyInnerImpl {
7+
8+
9+
public MyInterface returnInner (){
10+
return this.new MyInner();
11+
}
12+
}

‎src/test/java/org/thinkinjava/others/Learn1.java

+38
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,38 @@
1+
package org.thinkinjava.others;
2+
3+
import org.junit.Test;
4+
5+
public class Learn1 {
6+
7+
/**
8+
* 测试基本类型的==
9+
*/
10+
@Test
11+
public void test01(){
12+
int a = 1;
13+
long b = 1;
14+
double c = 1;
15+
System.out.println(a == b);
16+
System.out.println(a == c);
17+
}
18+
19+
@Test
20+
public void test02(){
21+
Integer a = 1;
22+
Double b = 1.0;
23+
Long c = 1L;
24+
System.out.println(a.equals(b));
25+
System.out.println(a.equals(c));
26+
}
27+
28+
@Test
29+
public void test03(){
30+
Integer a = 1;
31+
Integer b = new Integer(1);
32+
Integer c = new Integer(1);
33+
System.out.println("a.equals(b) : " + a.equals(b));
34+
System.out.println("a == b : " + (a == b));
35+
System.out.println("b.equals(c) : " + b.equals(c));
36+
System.out.println("b == c : " + (b == c));
37+
}
38+
}

‎src/test/java/org/thinkinjava/others/Learn2.java

+50
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,50 @@
1+
package org.thinkinjava.others;
2+
3+
import org.junit.Test;
4+
5+
class User {
6+
private String name;
7+
8+
public String getName() {
9+
return name;
10+
}
11+
12+
public void setName(String name) {
13+
this.name = name;
14+
}
15+
}
16+
17+
class Users {
18+
private User user1;
19+
20+
private User user2;
21+
22+
public Users(){
23+
user1 = new User();
24+
}
25+
public User getUser1() {
26+
return user1;
27+
}
28+
29+
public void setUser1(User user1) {
30+
this.user1 = user1;
31+
}
32+
33+
public User getUser2() {
34+
return user2;
35+
}
36+
37+
public void setUser2(User user2) {
38+
this.user2 = user2;
39+
}
40+
}
41+
public class Learn2 {
42+
43+
@Test
44+
public void test01(){
45+
User user = new User();
46+
user.setName("aaa");
47+
48+
Users users = new Users();
49+
}
50+
}

0 commit comments

Comments
 (0)