The Java Tutorials have been written for JDK 8.Java教程是为JDK 8编写的。Examples and practices described in this page don't take advantage of improvements introduced in later releases and might use technology no longer available.本页中描述的示例和实践没有利用后续版本中引入的改进，并且可能使用不再可用的技术。See Java Language Changes for a summary of updated language features in Java SE 9 and subsequent releases.有关Java SE 9及其后续版本中更新的语言特性的摘要，请参阅Java语言更改。
See JDK Release Notes for information about new features, enhancements, and removed or deprecated options for all JDK releases.有关所有JDK版本的新功能、增强功能以及已删除或不推荐的选项的信息，请参阅JDK发行说明。
Below is the source code for ExampleGame. For simplicity, ExampleGame does not actually contain code to play a game. It simply retrieves or updates a user's high score.
To see what the user's current high score value is, you could run:
java ExampleGame get
To set a new high score value for the user, you could run:
java ExampleGame set score
To retrieve the user's current high score, ExampleGame simply instantiates a HighScore object and makes a call to its getHighScore method. To set a new high score for the user, ExampleGame instantiates a HighScore object and calls setHighScore, passing it the user's new high score.
Here is the source code for ExampleGame, ExampleGame.java:
package com.gamedev.games;
import java.io.*;
import java.security.*;
import java.util.Hashtable;
import com.scoredev.scores.*;
public class ExampleGame
{
public static void main(String args[])
throws Exception
{
HighScore hs = new HighScore("ExampleGame");
if (args.length == 0)
usage();
if (args[0].equals("set")) {
hs.setHighScore(Integer.parseInt(args[1]));
} else if (args[0].equals("get")) {
System.out.println("score = "+ hs.getHighScore());
} else {
usage();
}
}
public static void usage()
{
System.out.println("ExampleGame get");
System.out.println("ExampleGame set <score>");
System.exit(1);
}
}