Question

一道Java练习题

1. 定义论坛的帖子类（Topic），拥有属性：标题（title）、内容（content）、发表时间（publishTime）、用户（user）、所属板块（board），回复（fTopics ArrayList），无参数构造方法对属性进行默认初始化，有参数构造方法，对所有属性进行初始化，显示信息方法（toString（））
编写测试类 设置帖子信息，并输出调用输出方法，输出帖子信息，包括子贴信息
例如：
标题：报道帖
内容：初来乍到请各位多多指教！
用户：张三
回复：
1楼：
标题：re：报道帖
内容：欢迎，欢迎，热烈欢迎
用户：李四
2楼：
标题：re：报道帖
内容：路过，我是来打酱油的
用户：马五
3楼：
标题：哈哈
内容：板凳哦！~~~
用户：王六
求答案，答案满意的会加分

Answer 1

import java.util.ArrayList;
import java.util.Iterator;

/**
*
*/

/**
* @author Think
*
*/
public class TestTopics {

/**
*
*/
public TestTopics() {
// TODO Auto-generated constructor stub
}

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Topic parentTopic = new Topic("报道帖","初来乍到请各位多多指教！","张三","","");
Topic child1 = new Topic();
Topic child2 = new Topic();
Topic child3 = new Topic();

child1.setContent("欢迎，欢迎，热烈欢迎");
child1.setTitle("re:" + parentTopic.getTitle());
child1.setUser("李四");

child2.setContent("路过，我是来打酱油的");
child2.setTitle("re:" + parentTopic.getTitle());
child2.setUser("马五");

child3.setContent("板凳哦！~~~");
child3.setTitle("哈哈");
child3.setUser("王六");

parentTopic.addChildTopic(child1);
parentTopic.addChildTopic(child2);
parentTopic.addChildTopic(child3);

System.out.println(parentTopic.toString());
}

}

class Topic
{
public Topic()
{
this.title = "";
this.content = "";
this.publishTime = "";
this.user = "";
this.board = "";
}

public Topic(String title,String content,String user,String board,String publishTime)
{
this.title = title;
this.content = content;
this.publishTime = publishTime;
this.user = user;
this.board = board;
}

public void addChildTopic(Topic child)
{
// child.setTitle("re:" + title);
fTopics.add(child);
}

public String toString()
{
StringBuffer sb = new StringBuffer();

if(fTopics.size() != 0)
{

sb.append("标题:").append(title).append("\n");
sb.append("内容:").append(content).append("\n");
sb.append("用户:").append(user).append("\n");
sb.append("回复:").append("\n");

int n = 1;

Iterator<Topic> iterator = fTopics.iterator();

while (iterator.hasNext()) {
Topic topic = (Topic) iterator.next();
sb.append(" ");
sb.append(n++).append("楼:\n");
sb.append(topic.toString());
}
}
else {
sb.append(" ");
sb.append("标题:").append(title).append("\n");
sb.append(" ");
sb.append("内容:").append(content).append("\n");
sb.append(" ");
sb.append("用户:").append(user).append("\n");
}

return sb.toString();

}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
public String getPublishTime() {
return publishTime;
}
public void setPublishTime(String publishTime) {
this.publishTime = publishTime;
}
public String getUser() {
return user;
}
public void setUser(String user) {
this.user = user;
}
public String getBoard() {
return board;
}
public void setBoard(String board) {
this.board = board;
}
private String title,content,publishTime;
private String user,board;
private ArrayList<Topic> fTopics = new ArrayList<Topic>();
}